Android 截屏技术-蒲公英云

虽然Android系统提供了以组合键的方式来截图，但是有时我们并不需要这么麻烦，而是想尽可能的简单的实现。基于这样的需求，前些天在开发应用时，碰到了屏幕截屏技术，没接触前以为很难，需要写各种代码，各种逻辑，接触后，发现实现关键代码就几行。但是并不满足于现状的我，很快就发现它并不能截取其他应用的界面，于是查了很多资料，还是很失望的，对手机的要求很高，要root，这大概就是市面上很多的截图应用为什么都需要root权限的原因。好吧，先写下应用内截图的几种方式吧，其实都大同小异。

activity_main.xml

<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:id="@+id/rootView"
    android:background="#98761f"
    tools:context="com.example.screenshoot.MainActivity" >
    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    <Button
        android:id="@+id/bt1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:text="截屏技术1111"
        android:layout_below="@+id/textView1"
        android:layout_marginTop="16dp" />
    <Button
        android:id="@+id/bt2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/bt"
        android:layout_below="@+id/bt1"
        android:layout_marginTop="30dp"
        android:text="截屏技术2222" />
    <Button
        android:id="@+id/bt3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/bt2"
        android:layout_marginTop="33dp"
        android:text="截屏技术3333" />
</RelativeLayout>

MainActivity.java

package com.example.screenshoot;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener {
    private Button bt1, bt2, bt3;
    View rootView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        bt1 = (Button) findViewById(R.id.bt1);
        bt2 = (Button) findViewById(R.id.bt2);
        bt3 = (Button) findViewById(R.id.bt3);
        bt1.setOnClickListener(this);
        bt2.setOnClickListener(this);
        bt3.setOnClickListener(this);
        rootView= findViewById(R.id.rootView);
    }
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.bt1:// View的getDrawingCache()方法      
            View view = this.getWindow().getDecorView();
            //或者View view=v.getRootView();
            view.setPressed(false);//这样就不会截取到button被按下的状态
            view.setDrawingCacheEnabled(true);
            view.buildDrawingCache();
            Bitmap b1 = view.getDrawingCache();
            // 获取状态栏高度
            Rect frame = new Rect();
            this.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);
            int statusBarHeight = frame.top;
            Log.i("TAG", "" + statusBarHeight);
            // 获取屏幕长和高
            int width = getResources().getDisplayMetrics().widthPixels;
            int height =getResources().getDisplayMetrics().heightPixels;
            // 去掉标题栏
            // Bitmap b = Bitmap.createBitmap(b1, 0, 25, 320, 455);
            Bitmap bitmap = Bitmap.createBitmap(b1, 0, statusBarHeight, width,
                    height - statusBarHeight);
            saveMyBitmap("noTitle", bitmap);// 去掉标题栏的
            saveMyBitmap("hadTitle", b1);
            view.destroyDrawingCache();
            break;
        case R.id.bt2:
            // TODO Auto-generated method stub
            Bitmap newb = Bitmap.createBitmap(getResources().getDisplayMetrics().widthPixels, getResources().getDisplayMetrics().heightPixels, Config.ARGB_8888);
            Canvas canvas = new Canvas(newb);
            rootView.draw(canvas);
            File file = new File(Environment.getExternalStorageDirectory()
                    + "/" + "secondMethod.png");
            FileOutputStream f = null;
            try {
                f = new FileOutputStream(file);
            } catch (FileNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            boolean b = newb.compress(Bitmap.CompressFormat.PNG, 100, f);
            try {
                f.flush();
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                f.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (b) {
                // 截图成功
                Toast.makeText(this, "截图成功", 1).show();
            }
            break;
        case R.id.bt3:
            saveMyBitmap("thirdMethod", getViewBitmap(v));;
            break;
        default:
            break;
        }
    }
    /**
     * 保存bitmap到sd卡(本项目的file文件夹下)
     * 
     * @param bitName
     * @param mBitmap
     */
    public void saveMyBitmap(String bitName, Bitmap mBitmap) {
        File f = new File(getFilesDir(), bitName + ".png");
        try {
            f.createNewFile();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            // DebugMessage.put("在保存图片时出错："+e.toString());
            e.printStackTrace();
        }
        FileOutputStream fOut = null;
        try {
            fOut = new FileOutputStream(f);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        mBitmap.compress(Bitmap.CompressFormat.PNG, 100, fOut);
        try {
            fOut.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            fOut.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static Bitmap getViewBitmap(View v) {
        v.clearFocus(); //
        v.setPressed(false); //
        // 能画缓存就返回false
        boolean willNotCache = v.willNotCacheDrawing();
        v.setWillNotCacheDrawing(false);
        int color = v.getDrawingCacheBackgroundColor();
        v.setDrawingCacheBackgroundColor(0);
        if (color != 0) {
            v.destroyDrawingCache();
        }
        v.buildDrawingCache();
        Bitmap cacheBitmap = v.getDrawingCache();
        if (cacheBitmap == null) {
            return null;
        }
        Bitmap bitmap = Bitmap.createBitmap(cacheBitmap);
        // Restore the view
        v.destroyDrawingCache();
        v.setWillNotCacheDrawing(willNotCache);
        v.setDrawingCacheBackgroundColor(color);
        return bitmap;
    }
}