package com.example.imagedemotext;

import java.io.ByteArrayOutputStream;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.InputStream;

import java.util.ArrayList;

import java.util.List;

import android.app.Activity;

import android.content.ContentResolver;

import android.content.Intent;

import android.database.Cursor;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.net.Uri;

import android.os.Bundle;

import android.provider.MediaStore.Images.Thumbnails;

import android.view.View;

import android.view.View.OnClickListener;

import android.view.ViewGroup;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemClickListener;

import android.widget.BaseAdapter;

import android.widget.Button;

import android.widget.GridView;

import android.widget.ImageView;

public class MainActivity extends Activity {

    Button btn_start;

    GridView gridview;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        btn_start = (Button) findViewById(R.id.btn_start);

        gridview = (GridView) findViewById(R.id.gridview);

        adapter = new Myadapter();

        iniLisner();

        inidata();

    }

    private void refreshAdapter(){

        if(list == null){

            list = new ArrayList<String>();

        }

        if(adapter == null){

            adapter = new Myadapter();

        }

        if(list.size() == ON){

            list.remove(list.size() - 1);

        }

        adapter.notifyDataSetChanged();

    }

    private final int ON = 5;  //允许的图片数量 + 1

    private void inidata() {

        if(list == null){

            list = new ArrayList<String>();

            list.add("a");  //添加默认图片

        }

        gridview.setAdapter(adapter);

        gridview.setOnItemClickListener(new OnItemClickListener() {

            @Override

            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

                if(list.get(position).equals("a")){

                    setClick();

                }

            }

        });

        refreshAdapter();

    }

    Myadapter adapter;

    class Myadapter extends BaseAdapter{

        @Override

        public int getCount() {return list.size();}

        @Override

        public Object getItem(int position) {return null;}

        @Override

        public long getItemId(int position) {return 0;}

        @Override

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

            ViewHolder vh = null;

            if(convertView == null){

                convertView = View.inflate(getApplicationContext(), R.layout.item, null);

                vh = new ViewHolder();

                vh.iamge = (ImageView) convertView.findViewById(R.id.image);

                convertView.setTag(vh);

            }else {

                vh = (ViewHolder) convertView.getTag();

            }

            if(list.get(position).equals("a")){  //添加默认图片

                vh.iamge.setImageResource(R.drawable.ic_launcher);

            }else {

                Bitmap loacalBitmap = getLoacalBitmap(list.get(position));

                if(loacalBitmap != null){

                    vh.iamge.setImageBitmap(loacalBitmap);

                }

            }

            return convertView;

        }

    }

    class ViewHolder {

        ImageView iamge;

    }

    private void iniLisner() {

        if(btn_start != null){

            btn_start.setOnClickListener(new OnClickListener() {

                @Override

                public void onClick(View v) {

                    setClick();

                }

            });

        }

    }

    private void setClick(){

        Intent getImage = new Intent(Intent.ACTION_GET_CONTENT);

        getImage.addCategory(Intent.CATEGORY_OPENABLE);

        getImage.setType("image/jpeg");

        startActivityForResult(getImage, 0);

    }

    private byte[] mContent;

    private List<String> list;

    @Override

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        super.onActivityResult(requestCode, resultCode, data);

        ContentResolver resolver = getContentResolver();

        if(data == null){

            return;

        }

        if (requestCode == 0) {

            try {

                Uri originalUri = data.getData();

                mContent = readStream(resolver.openInputStream(Uri.parse(originalUri.toString())));

                String path = originalUri.toString();

                ContentResolver testcr = getContentResolver();

                Cursor cur = testcr.query(originalUri, null, null, null, null);

                if(list.size() == ON){

                    removeItem();

                    refreshAdapter();

                    return;

                }

                removeItem();

                for (cur.moveToFirst(); !cur.isAfterLast(); cur.moveToNext()) {

                    int dataColumn = cur.getColumnIndex(Thumbnails.DATA);

                    String image_path = cur.getString(dataColumn);

                    list.add(image_path);

                }

                list.add("a");

                refreshAdapter();

            } catch (Exception e) {

                System.out.println(e.getMessage());

            }

        } 

    }

    private void removeItem() {

        if(list.size() -1 != ON){

            if(list.size() != 0){  //删除默认图片

                list.remove(list.size() - 1);

            }

        }

    }

    public static byte[] readStream(InputStream inStream) throws Exception {

        byte[] buffer = new byte[1024];

        int len = -1;

        ByteArrayOutputStream outStream = new ByteArrayOutputStream();

        while ((len = inStream.read(buffer)) != -1) {

            outStream.write(buffer, 0, len);

        }

        byte[] data = outStream.toByteArray();

        outStream.close();

        inStream.close();

        return data;

    }

    public static Bitmap getLoacalBitmap(String url) {

         try {

              FileInputStream fis = new FileInputStream(url);

              return BitmapFactory.decodeStream(fis);

         } catch (FileNotFoundException e) {

              e.printStackTrace();

              return null;

         }

    }

}

<LinearLayout 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:orientation="vertical"

    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" >

    <TextView

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="点击按钮选择一个图片后会显示在下面的GridView" />

    <Button

        android:id="@+id/btn_start"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:text="获取图片" />

    <View

        android:layout_width="match_parent"

        android:layout_height="9dp"

        android:background="#a0000000" />

    <GridView

        android:id="@+id/gridview"

        android:layout_width="match_parent"

        android:layout_height="match_parent" >

    </GridView>

</LinearLayout>

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

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

    android:layout_width="wrap_content"

    android:layout_height="wrap_content"

    android:orientation="vertical" >

    <ImageView

        android:id="@+id/image"

        android:layout_width="40dp"

        android:layout_height="40dp"

 />

</LinearLayout>