view 相关代码片段笔记

代码中动态创建view,并把AttributeSet加入到当前自定义的view中,动态创建属性相关

 //https://blog.csdn.net/chenhuakang/article/details/53584429

    public static AttributeSet getAttribute(Context ctx,int layoutId){

        XmlPullParser parser = null;

        AttributeSet attributes = null;

        int type;

        try{

            parser = ctx.getResources().getXml(layoutId);//R.layout.textview

            attributes = Xml.asAttributeSet(parser);

            while ((type = parser.next()) != XmlPullParser.START_TAG &&

                    type != XmlPullParser.END_DOCUMENT) {

                // Empty

            }

            if (type != XmlPullParser.START_TAG) {

                throw new InflateException(parser.getPositionDescription()

                        + ": No start tag found!");

            }

        }catch (Resources.NotFoundException e){

            throw new IllegalArgumentException("xml file not found error!");

        }

        catch (XmlPullParserException e) {

            InflateException ex = new InflateException(e.getMessage());

            ex.initCause(e);

            throw ex;

        } catch (IOException e) {

            InflateException ex = new InflateException(

                    parser.getPositionDescription()

                            + ": " + e.getMessage());

            ex.initCause(e);

            throw ex;

        }

        return attributes;

    }

使用:

 AttributeSet attr =  ViewsHelper.getAttribute(act, R.layout.template_setitem);

            SettingItemCommon commonSettingItem = new SettingItemCommon(act,attr);

            commonSettingItem.setItemContent(item.name,item.desc,true);

Recycleview属性分割线处理

public static void initRecycleViewParams(RecyclerView rl,boolean needDivide){

        LinearLayoutManager layoutMag = new LinearLayoutManager(AppAppliacation.getAppContext());

        layoutMag.setOrientation(LinearLayoutManager.VERTICAL);

        rl.setLayoutManager(layoutMag);

        if(needDivide) {

            DividerItemDecoration divider = new DividerItemDecoration(rl.getContext(), DividerItemDecoration.VERTICAL);

            divider.setDrawable(ContextCompat.getDrawable(rl.getContext(), R.drawable.divider2));

            rl.addItemDecoration(divider);

        }

    }

绘图内容在padding外显示（默认为内部）

clipToPadding就是说控件的绘制区域是否在padding里面的
clipChildren是指子控件是否超过padding区域
两个属性设置了false那么这样子控件就能画到padding的区域了。

获取activity contentview视图

activity.findViewById(Window.ID_ANDROID_CONTENT)

// Hijack the decorview

		ViewGroup decorView = (ViewGroup)activity.getWindow().getDecorView();

		View oldScreen = decorView.getChildAt(0);

		decorView.removeViewAt(0);

		// Setup the slider panel and attach it to the decor

		SliderPanel panel = new SliderPanel(activity, oldScreen, config);

		panel.setId(R.id.slidable_panel);

		oldScreen.setId(R.id.slidable_content);

		panel.addView(oldScreen);

		decorView.addView(panel, 0);

viewTree绘制状态监听：

(1)ViewTreeObserver实现

final ViewTreeObserver observer = layoutContainer.getViewTreeObserver();

        observer.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

            @Override

            public void onGlobalLayout() {

                //判断ViewTreeObserver 是否alive，如果存活的话移除这个观察者

                if(observer.isAlive()){

                    observer.removeOnGlobalLayoutListener(this);

                    int viewWidth=view.getMeasuredWidth();

                    int viewHeight=view.getMeasuredHeight();

                }

            }

        });

        observer.addOnDrawListener(new ViewTreeObserver.OnDrawListener() {

            @Override

            public void onDraw() {

                if(observer.isAlive()){

                    observer.removeOnDrawListener(this);

                }

            }

        });

(2)Choreographer方式：

@Override

    protected void onResume() {

        super.onResume();

        Choreographer.getInstance().postFrameCallback(new Choreographer.FrameCallback() {

            @Override

            public void doFrame(long frameTimeNanos) {

                start = SystemClock.uptimeMillis();

                log("绘制开始:height = "+view.getHeight());

            }

        });

    }

在activity中获取fragment中的控件

getFragmentManager().findFragmentById(id).getView().findViewById(id)

EditText click事件无反应问题，

原因：touch事件影响 OnTouch -> OnFocusChange -> OnClick.

解决：使用TouchListener替换Click事件

edit.setOnTouchListener(new View.OnTouchListener() {//click事件处理

                @Override

                public boolean onTouch(View v, MotionEvent event) {

                    if(MotionEvent.ACTION_UP == event.getAction()){

                        if(null!=changeLayout)

                            changeLayout.setVisibility(View.GONE);

                    }

                    return false;//注意返回

                }

            });

自定义处理focus:

禁用 android:focusable="false"

设置focusListener

//            edit.setOnFocusChangeListener(new View.OnFocusChangeListener() {//焦点处理

//                @Override

//                public void onFocusChange(View v, boolean hasFocus) {

//                    if(hasFocus)

//                        Toast.makeText(getApplicationContext(), "onFocusChange", Toast.LENGTH_LONG).show();

//                }

//            });

实现AutoCompleteTextView,SearchView功能

使用Listview+EditTextview+Filter Adatpter

1,Filter Adatpter处理

package com.bjzjkj.net.deviceapp.simcard_module.adapter;

import android.content.Context;

import android.util.AttributeSet;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import android.widget.Filter;

import android.widget.FrameLayout;

import android.widget.ImageView;

import android.widget.TextView;

import com.bjzjkj.net.deviceapp.R;

import java.util.ArrayList;

import java.util.List;

/**

 * Created by yudajun on 2017/6/16.

 * 弹出框下拉样式

 */

public class CommonPopviewListAdapter extends BaseAdapter {

    private Context mContext;

    private List<CommonItemModel> sunItems ,filteredData ;

    public CommonPopviewListAdapter(Context mContext,List<CommonItemModel> items) {

        this.mContext = mContext;

        this.sunItems = items;

        this.filteredData = items;

    }

    public void setData(List<CommonItemModel> items){

        this.sunItems = items;

        this.filteredData = items;

        notifyDataSetChanged();

    }

    @Override

    public View getView(int position, View convertView, ViewGroup parent) {

        HolderView holderView;

        // Important to not just null check, but rather to a instanceof

        // since we might get any subclass of view here.

        if (convertView instanceof HolderView) {

            holderView = (HolderView) convertView;

        } else {

            holderView = new HolderView(mContext, null);

        }

        holderView.bindData(filteredData.get(position).text);

        return holderView;

    }

    @Override

    public int getCount() {

        return filteredData.size();

    }

    @Override

    public CommonItemModel getItem(int position) {

        return filteredData.get(position);

    }

    @Override

    public long getItemId(int id) {

        return id;

    }

    private ItemFilter mFilter = new ItemFilter();

    public Filter getFilter() {

        return mFilter;

    }

    private class HolderView extends FrameLayout {

        private ImageView ivIcon;

        private TextView tvTitle;

        public HolderView(Context context, AttributeSet attrs) {

            super(context, attrs);

            View v = LayoutInflater.from(context).inflate(R.layout.common_pop_item, this);

            tvTitle = (TextView) v.findViewById(R.id.tvTitle);

        }

        public void bindData(String title) {

            tvTitle.setText(title);

        }

    }

    private class ItemFilter extends Filter {//过滤匹配结果

        @Override

        protected FilterResults performFiltering(CharSequence constraint) {

            String filterString = constraint.toString().toLowerCase();

            FilterResults results = new FilterResults();

            final List<CommonItemModel> list = sunItems;

            int count = list.size();

            final List<CommonItemModel> nlist = new ArrayList<CommonItemModel>(count);

            String filterableString ;

            for (int i = 0; i < count; i++) {

                filterableString = list.get(i).text;

                if (filterableString.toLowerCase().contains(filterString)) {

                    nlist.add(list.get(i));

                }

            }

            results.values = nlist;

            results.count = nlist.size();

            return results;

        }

        @Override

        protected void publishResults(CharSequence constraint, FilterResults results) {

            filteredData = (List<CommonItemModel>) results.values;

            notifyDataSetChanged();

        }

    }

    public static class CommonItemModel{

        public String text;

        public String workShopId;//车间id

        public String productId;

        public String typeDetail;

    }

}

2, EditText监听

@Override

        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override

        public void onTextChanged(CharSequence s, int start, int before, int count) {

            mSearchContentLv.setVisibility(View.VISIBLE);

            mSearchableAdapter.getFilter().filter(s.toString());

        }

        @Override

        public void afterTextChanged(Editable s) {

        }

HolderView item view 处理

@Override

public View getView(int i, View convertView, ViewGroup viewGroup) {

    HolderView holderView;

    // Important to not just null check, but rather to a instanceof

    // since we might get any subclass of view here.

    if (convertView instanceof HolderView) {

        holderView = (HolderView) convertView;

    } else {

        holderView = new HolderView(mContext);

    }

    holderView.bind(new Digit(i));

    return holderView;

}

class HolderView extends FrameLayout{

        //private Context ctx;

        private View vroot;

        public HolderView(Context context) {

            super(context);

            init(context);

        }

        public HolderView(Context context, AttributeSet attrs, View vroot) {

            super(context, attrs);

            init(context);

        }

        private void init(Context context){

            vroot = LayoutInflater.from(context).inflate(R.layout.flyrecoder_item, this);

            ButterKnife.bind(this, vroot);

        }

		void bindData(FlyRecordData model){

					this.tv_fly_record_item_title.setText(model.itemTitle);

					this.tv_fly_record_title_today.setText(model.todayData);

		｝

 ｝

在展示窗体内容时添加对view统一处理

mLayoutInflater = (LayoutInflater) activity

                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        mViewGroup = (ViewGroup) activity

                .findViewById(android.R.id.content);

        mToastView = mLayoutInflater.inflate(R.layout.supertoast,

                mViewGroup, false);

        mMessageTextView = (TextView) mToastView

                .findViewById(R.id.message_textview);

指定content view中头部或底部加入其它的view

private void setPoppyViewOnView(View view) {

		LayoutParams lp = view.getLayoutParams();

		ViewParent parent = view.getParent();

		ViewGroup group = (ViewGroup)parent;

		int index = group.indexOfChild(view);

		final FrameLayout newContainer = new FrameLayout(mActivity);

		group.removeView(view);

		group.addView(newContainer, index, lp);

		newContainer.addView(view);

		final FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);

		layoutParams.gravity = mPoppyViewPosition == PoppyViewPosition.BOTTOM ? Gravity.BOTTOM : Gravity.TOP;

		newContainer.addView(mPoppyView, layoutParams);

		group.invalidate();

	}

public enum PoppyViewPosition {

		TOP, BOTTOM

	};

private View mPoppyView;

强制measure childview 方法：

 private void measureView(View child) {

        ViewGroup.LayoutParams p = child.getLayoutParams();

        if (p == null) {

            p = new ViewGroup.LayoutParams(

                    ViewGroup.LayoutParams.FILL_PARENT,

                    ViewGroup.LayoutParams.WRAP_CONTENT);

        }

        int childWidthSpec = ViewGroup.getChildMeasureSpec(0,

                0 + 0, p.width);

        int lpHeight = p.height;

        int childHeightSpec;

        if (lpHeight > 0) {

            childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY);

        } else {

            childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);

        }

        child.measure(childWidthSpec, childHeightSpec);

    }

设置图片叠加层（参差不齐效果）

Drawable[] array = new Drawable[2];

array[0] = getResources().getDrawable(R.drawable.qq_girl);

array[1] = getResources().getDrawable(R.drawable.qq_boy);

LayerDrawable la = new LayerDrawable(array);

// 其中第一个参数为层的索引号，后面的四个参数分别为left、top、right和bottom

la.setLayerInset(0, 0, 0, 0, 0);

la.setLayerInset(1, 18, 35, 180, 76);

image.setImageDrawable(la);  

也可在xml实现

<?xml version="1.0" encoding="utf-8"?>

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

    <item android:drawable="@drawable/compassbackground" />

    <item android:drawable="@drawable/compass_text" />

</layer-list>

扩大控件有效点击区域（以imageview为例，当图片较小时，点击会有不灵敏感觉）这里需要设置scaleType属性

改进：

<ImageView

      android:layout_width="100dp"

      android:layout_height="100dp"

       android:src="@drawable/edit"

      android:scaleType="centerInside"/>

这里设置路ImageView的大小，这个大小区域就是ImageViwe的有效的点击区域，可以根据自己的情况修改大小

需要注意的是：要使用 src 不能使用background 否则图像会被拉伸

使用TouchDelegate扩展区域：

public static void setTouchDelegate(final View view, final int expandTouchWidth) {

        final View parentView = (View) view.getParent();

        parentView.post(new Runnable() {

            @Override

            public void run() {

                final Rect rect = new Rect();

                view.getHitRect(rect); // view构建完成后才能获取，所以放在post中执行

                rect.top -= expandTouchWidth;

                rect.bottom += expandTouchWidth;

                rect.left -= expandTouchWidth;

                rect.right += expandTouchWidth;

                parentView.setTouchDelegate(new TouchDelegate(rect, view));

            }

        });

    }

在touch屏幕上某点时，判断点击是否在某个widget控件内：

Rect mTouchRect = new Rect();

 private boolean isTouchedView(View view, float x, float y) {

        view.getHitRect(mTouchRect);

        // by taping top or bottom padding, the list performs on click on a border item.

        // we don't add top padding here to keep behavior consistent.

      //  mTouchRect.top += mTranslateY;

      //  mTouchRect.bottom += mTranslateY + getPaddingTop();

      //  mTouchRect.left += getPaddingLeft();

      //  mTouchRect.right -= getPaddingRight();

        return mTouchRect.contains((int)x, (int)y);

    }

activity设置背景透明 getWindow().setBackgroundDrawable(new ColorDrawable(android.graphics.Color.TRANSPARENT));

view背景透明设置

android:background

以下两种方法设置背景为透明："@android :color/transparent"和"@null"

GirdView,ListView设置divide透明 gridView.setSelector(new ColorDrawable(Color.TRANSPARENT));

隐去标题栏, 隐去状态栏 android:theme="@android:style/Theme.NoTitleBar.Fullscreen"

设置透明背景，修改AndroidManifest.xml文件，在对应的Activity里面加上下面的属性：

android:theme="@android:style/Theme.Translucent"

使用系统背景作为应用的背景，在onCreate的时候添加窗口标志：

getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WALLPAPER);

android:theme="@android:style/Theme.Dialog"

dialog级别设置 ctx不依赖Activity

AlertDialog mDialog=dialog.create();

mDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);//设定为系统级警告，关键

<activity android:windowSoftInputMode="stateVisible|adjustResize" . . . >

该Activity主窗口总是被调整屏幕的大小以便留出软键盘的空间

//强制为横屏

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

<activity android:name=".HandlerActivity" android:screenOrientation="landscape"/>

//强制为竖屏

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

<activity android:name=".HandlerActivity" android:screenOrientation="portrait"/>

AndroidManifest.xml 中设置属性禁止重新创建Activity,并且添加屏幕切换监听。

<activity android:name=".HandlerActivity"

sdk<3.2 android:configChanges="orientation|keyboardHidden"/>

dk>3.2 android:configChanges="orientation|screenSize"

handler清理所有消息内容 mHandler.removeCallbacksAndMessages(null);

//获取View在窗口/屏幕中的位置

TextView tv= (TextView) findViewById(R.id.tv);

int loc[]=new int[2];

tv.getLocationInWindow(loc);

Log.e("TAG",loc[0]+" "+loc[1]);

根据widget资源名称获取对应ID：

int resID = getResources().getIdentifier("widget_id", "id", getPackageName());

View addButton = findViewById(resID);

View中的isShown()方法，以前都是用view.getVisibility() == View.VISIBLE来判断的，但是与这个函数还是有区别的。

也就是只有当view本身和它的所有父容器都是visible时，isShown()才返回TRUE。

而平常我们调用if(view.getVisibility() == View.VISIBLE)只是对view本身而不对父容器的可见性进行判断。

直接获取view，不需要强制转型

public static <T> T $(View vroot,int viewID) {

return (T) vroot.findViewById(viewID);

}

使用：

Button takePicture = Utils.$(v, R.id.start_camera);

颜色值创建Drawable对象

private Drawable createDrawable(int color) {

        OvalShape ovalShape = new OvalShape();

        ShapeDrawable shapeDrawable = new ShapeDrawable(ovalShape);

        shapeDrawable.getPaint().setColor(color);

        if (mShadow && !hasLollipopApi()) {

            Drawable shadowDrawable = getResources().getDrawable(mType == TYPE_NORMAL ? R.drawable.fab_shadow

                    : R.drawable.fab_shadow_mini);

            LayerDrawable layerDrawable = new LayerDrawable(new Drawable[]{shadowDrawable, shapeDrawable});

            layerDrawable.setLayerInset(1, mShadowSize, mShadowSize, mShadowSize, mShadowSize);

            return layerDrawable;

        } else {

            return shapeDrawable;

        }

    }

代码实现按钮按压效果颜色变化：

private void updateBackground() {

        StateListDrawable drawable = new StateListDrawable();

        drawable.addState(new int[]{android.R.attr.state_pressed}, createDrawable(mColorPressed));

        drawable.addState(new int[]{-android.R.attr.state_enabled}, createDrawable(mColorDisabled));

        drawable.addState(new int[]{}, createDrawable(mColorNormal));

        setBackground(drawable);

    }

悬浮属性设置：

UC浏览器中文版出了一个快速搜索的功能,

显示这个悬浮窗不需要申请android.permission.SYSTEM_ALERT_WINDOW权限

一般设置成TYPE_PHONE就可以悬浮在很多view的上方了, 但是调用这个方法需要申请android.permission.SYSTEM_ALERT_WINDOW权限,

将type设置成TYPE_TOAST果然有奇效, 但是在2.3上不能接收点击事件.

TYPE_APPLICATION_PANEL: 只能配合Activity在当前APP使用(PopupWindow默认就是这个Type)

TYPE_CHANGED: 只能配合Activity在当前APP使用

绘制扇形进度加载

public void draw(Canvas canvas) {

        if (getHideWhenZero() && mLevel == 0) {

            return;

        }

        drawBar(canvas, maxLevel, getBackgroundColor());

        drawBar(canvas, mLevel, getColor());

    }

    private void drawBar(Canvas canvas, int level, int color) {

        Rect bounds = getBounds();

        RectF rectF = new RectF((float) (bounds.right * .4), (float) (bounds.bottom * .4),

                (float) (bounds.right * .6), (float) (bounds.bottom * .6));

        mPaint.setColor(color);

        mPaint.setStyle(Paint.Style.STROKE);

        mPaint.setStrokeWidth(6);

        if (level != 0)

            canvas.drawArc(rectF, 0, (float) (level * 360 / maxLevel), false, mPaint);

    }

屏幕截取

/**

     * 获取当前屏幕截图，包含状态栏

     */

    public static Bitmap snapShotWithStatusBar(Activity activity){

        View view = activity.getWindow().getDecorView();

        view.setDrawingCacheEnabled(true);

        view.buildDrawingCache();

        Bitmap bmp = view.getDrawingCache();

        int width = getScreenWidth(activity);

        int height = getScreenHeight(activity);

        Bitmap bp = null;

        bp = Bitmap.createBitmap(bmp, 0, 0, width, height);

        view.destroyDrawingCache();

        return bp;

    }

    /**

     * 获取当前屏幕截图，不包含状态栏

     *

     */

    public static Bitmap snapShotWithoutStatusBar(Activity activity){

        View view = activity.getWindow().getDecorView();

        view.setDrawingCacheEnabled(true);

        view.buildDrawingCache();

        Bitmap bmp = view.getDrawingCache();

        Rect frame = new Rect();

        activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);

        int statusBarHeight = frame.top;

        int width = getScreenWidth(activity);

        int height = getScreenHeight(activity);

        Bitmap bp = null;

        bp = Bitmap.createBitmap(bmp, 0, statusBarHeight, width, height

                - statusBarHeight);

        view.destroyDrawingCache();

        return bp;

    }

Bitmap大小计算

static int getBitmapBytes(Bitmap bitmap) {

    int result;

    if (SDK_INT >= HONEYCOMB_MR1) {

      result = BitmapHoneycombMR1.getByteCount(bitmap);

    } else {

      result = bitmap.getRowBytes() * bitmap.getHeight();

    }

    if (result < 0) {

      throw new IllegalStateException("Negative size: " + bitmap);

    }

    return result;

  }

保存恢复ListView当前位置

private void saveCurrentPosition() {

        if (mListView != null) {

            int position = mListView.getFirstVisiblePosition();

            View v = mListView.getChildAt(0);

            int top = (v == null) ? 0 : v.getTop();

            //保存position和top

        }

    }

    private void restorePosition() {

        if (mFolder != null && mListView != null) {

            int position = 0;//取出保存的数据

            int top = 0;//取出保存的数据

            mListView.setSelectionFromTop(position, top);

        }

    }

帮助、about、关于作者、HELP等的提示dialog页面

	//方法一：

 AlertDialog ad = new AlertDialog.Builder(SettingPreference.this)

	                        .setTitle(R.string.about_dlg_title)

	                        .setMessage(R.string.about_dlg_message)

	                        .setPositiveButton(getText(R.string.ok), null).create();

	                ad.show();

					//加入链接功能

	                Linkify.addLinks((TextView) ad.findViewById(android.R.id.message),

	                        Linkify.ALL);

//方法二：

//设计一个AboutDialog类继承于AlertDialog

public class AboutDialog extends AlertDialog {

    public AboutDialog(Context context) {

        super(context);

        final View view = getLayoutInflater().inflate(R.layout.about,

                null);

        setButton(context.getText(R.string.close), (OnClickListener) null);

        setIcon(R.drawable.icon_about);

        setTitle("程序版本   v1.0.0" );

        setView(view);

    }

布局文件about.xml

<?xml version="1.0" encoding="utf-8"?>

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="fill_parent" android:layout_height="wrap_content">

    <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"

        android:layout_width="fill_parent" android:layout_height="fill_parent">  

        <TextView android:layout_height="fill_parent"

            android:layout_width="fill_parent" android:text="@string/help_dialog_text"

            android:padding="6dip" android:textColor="#FFFFFF" />

    </ScrollView>

</FrameLayout>

自定义View相关问题:

measure解析:

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

		int width = getDefaultSize(mVideoWidth, widthMeasureSpec);

		int height = getDefaultSize(mVideoHeight, heightMeasureSpec);

		setMeasuredDimension(width, height);

	}

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

		int count = getChildCount();

		int maxHeight = 0;

		int maxWidth = 0;

		measureChildren(widthMeasureSpec, heightMeasureSpec);

		for (int i = 0; i < count; i++) {

			View child = getChildAt(i);

			if (child.getVisibility() != GONE) {

				int childRight;

				int childBottom;

				CenterLayout.LayoutParams lp = (CenterLayout.LayoutParams) child.getLayoutParams();

				childRight = lp.x + child.getMeasuredWidth();

				childBottom = lp.y + child.getMeasuredHeight();

				maxWidth = Math.max(maxWidth, childRight);

				maxHeight = Math.max(maxHeight, childBottom);

			}

		}

		maxWidth += mPaddingLeft + mPaddingRight;

		maxHeight += mPaddingTop + mPaddingBottom;

		maxHeight = Math.max(maxHeight, getSuggestedMinimumHeight());

		maxWidth = Math.max(maxWidth, getSuggestedMinimumWidth());

		setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec), resolveSize(maxHeight, heightMeasureSpec));

	}

@Override

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        //DensityUtils.dp2px(getContext(),40)+

        int minWidth = getPaddingLeft() + getPaddingRight();

        int minHeight = barHeight + getPaddingBottom() + getPaddingTop();

        int w = resolveSizeAndState(minWidth, widthMeasureSpec, 0);

        int h = resolveSizeAndState(minHeight, heightMeasureSpec, 0);

        setMeasuredDimension(w, h);

    }

绘制文本居中显示:

 public void drawTextCentredInRectWithSides(Canvas canvas, Paint paint, String text, float left, float top, float right, float bottom) {

        paint.setTextAlign(Paint.Align.CENTER);

        float textHeight = paint.descent() - paint.ascent();

        float textOffset = (textHeight / 2) - paint.descent();

        canvas.drawText(text, (left + right) / 2, (top + bottom) / 2 + textOffset, paint);

    }

绘制局部圆角

1，绘制完整圆角 canvas.drawRoundRect

2，去除部分圆角，在要去除地方，在绘制一次小的矩形使其变为方角

    private void clipTopLeft(final Canvas canvas, final Paint paint, int offset,int left,int top) {

        Rect block = new Rect(left, top, left+offset, top+offset);

        canvas.drawRect(block, paint);

    }

    private void clipTopRight(final Canvas canvas, final Paint paint, int offset, int right,int top) {

        Rect block = new Rect(right - offset, top, right, top+offset);

        canvas.drawRect(block, paint);

    }

    private void clipBottomLeft(final Canvas canvas, final Paint paint, int offset, int left, int bottom) {

        Rect block = new Rect(left, bottom - offset, left+offset, bottom);

        canvas.drawRect(block, paint);

    }

    private void clipBottomRight(final Canvas canvas, final Paint paint, int offset, int right, int bottom) {

        Rect block = new Rect(right - offset, bottom - offset, right, bottom);

        canvas.drawRect(block, paint);

    }

带进度webview

public class ProgressWebView extends WebView {

    private ProgressBar progressbar;

    public ProgressWebView(Context context, AttributeSet attrs) {

        super(context, attrs);

        progressbar = new ProgressBar(context, null, android.R.attr.progressBarStyleHorizontal);

        progressbar.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, 3, 0, 0));

        addView(progressbar);

        //        setWebViewClient(new WebViewClient(){});

        setWebChromeClient(new WebChromeClient());

    }

    public class WebChromeClient extends android.webkit.WebChromeClient {

        @Override

        public void onProgressChanged(WebView view, int newProgress) {

            if (newProgress == 100) {

                progressbar.setVisibility(GONE);

            } else {

                if (progressbar.getVisibility() == GONE)

                    progressbar.setVisibility(VISIBLE);

                progressbar.setProgress(newProgress);

            }

            super.onProgressChanged(view, newProgress);

        }

    }

    @Override

    protected void onScrollChanged(int l, int t, int oldl, int oldt) {

        LayoutParams lp = (LayoutParams) progressbar.getLayoutParams();

        lp.x = l;

        lp.y = t;

        progressbar.setLayoutParams(lp);

        super.onScrollChanged(l, t, oldl, oldt);

    }

}

textview文字图片一起水平居中

public class DrawableCenterTextView extends TextView {

......

    @Override

    protected void onDraw(Canvas canvas) {

        Drawable[] drawables = getCompoundDrawables();

        if (drawables != null) {

            Drawable drawableLeft = drawables[0];

            if (drawableLeft != null) {//左边图片处理

                float textWidth = getPaint().measureText(getText().toString());

                int drawablePadding = getCompoundDrawablePadding();

                int drawableWidth = 0;

                drawableWidth = drawableLeft.getIntrinsicWidth();

                float bodyWidth = textWidth + drawableWidth + drawablePadding;

                canvas.translate((getWidth() - bodyWidth) / 2, 0);

            }

        }

        Drawable drawableRight = drawables[2];

        if (drawableRight != null) {//右边图像处理

            float textWidth = getPaint().measureText(getText().toString());

            int drawablePadding = getCompoundDrawablePadding();

            int drawableWidth = 0;

            drawableWidth = drawableLeft.getIntrinsicWidth();

            float bodyWidth = textWidth + drawableWidth + drawablePadding;

            setPadding(0, 0, (int)(getWidth() - bodyWidth), 0);

            canvas.translate((getWidth() - bodyWidth) / 2, 0);

        }

        super.onDraw(canvas);

    }

}

底部导航tab中间button高出一部分内容

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:clipChildren="false"

    android:orientation="vertical" >

    <LinearLayout

        android:layout_width="match_parent"

        android:layout_height="48dip"

        android:background="#B0C4DE"

        android:orientation="horizontal" >

        <ImageView

            android:layout_width="0dip"

            android:layout_height="fill_parent"

            android:layout_weight="1.0"

            android:scaleType="fitCenter"

            android:src="@drawable/ic_launcher" />

         <ImageView

             android:layout_width="0dip"

            android:layout_height="64dip"

            android:layout_gravity="bottom"

            android:layout_weight="1.0"

            android:scaleType="fitCenter"

            android:src="@drawable/ic_launcher" />

    </LinearLayout>  

</LinearLayout>

1、只需在根节点设置android:clipChildren为false即可，默认为true
2、可以通过android:layout_gravity控制超出的部分如何显示。
3、android:clipChildren的意思：是否限制子View在其范围内

巴特西

view 相关代码片段笔记

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