Android  自己定义View须要重写ondraw()等方法。这篇博客给大家说说自己定义View的写法，须要我们继承View，然后重写一些

方法，方法多多，看你须要什么方法

首先写一个自己定义的View 继承View

package com.example.engineerjspview;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.util.AttributeSet;

import android.view.MotionEvent;

/**

 * 自己定义 EngineerJspView

 * @author Engineer-Jsp

 * @date 2014.10.28

 * */

import android.view.View;

public class EngineerJspView extends View{

	public float E_X = 188;

    public float E_Y = 188;

    Paint paint = new Paint(); 

	public EngineerJspView(Context context) {

		super(context);

	}

	public EngineerJspView(Context context, AttributeSet set){

		super(context, set);

	}

	@Override

	protected void onDraw(Canvas canvas) {

		super.onDraw(canvas);

		paint.setColor(Color.RED);

        canvas.drawCircle(E_X, E_Y, 88, paint);

	}

	@Override

	public boolean onTouchEvent(MotionEvent event) {

		 E_X = event.getX();

	     E_X = event.getY();

	        invalidate();

		return false;

	}

	@Override

	protected void onAnimationStart() {

		super.onAnimationStart();

	}

	@Override

	protected void onAnimationEnd() {

		super.onAnimationEnd();

	}

}

布局文件：

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

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context=".MainActivity" >

    <com.example.engineerjspview.EngineerJspView

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:layout_alignParentBottom="true"

        android:layout_centerHorizontal="true" />

</RelativeLayout>

主活动：

package com.example.engineerjspview;

/**

 * 自己定义 EngineerJspView

 * @author Engineer-Jsp

 * @date 2014.10.28

 * */

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.view.View;

public class MainActivity extends Activity {

	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_main);

	}

}

效果：

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自己定义View看你需求而定，并不仅仅是绘图形而已。我这里仅仅是说明下自己定义View须要重写的方法~~