总结了一个方法，实现了在Android当前Activity的截图，本人测试确实通过了，不过有朋友说截出来的图是黑色的，不能看。我心想，这没有问题啊，相同的代码我就可以执行通过，并没有没有在意这个问题。可是，今天我再调用那个方法时，截出来的图部分是黑屏。我当时就郁闷了。网上的东西很全，但同时很乱。有一个大神用的是引用Linux下编译出来的库，又用到什么JNI我完全不懂，貌似可以实现截屏。当时这个方法太麻烦，我看了一下觉得没有信心，就又继续寻找其他的方法。

我截图出现黑屏的原因是在Activity中用到了SurfaceView控件，在XML布局中的控件可以完整的显示出来但是有surfaceView的时候就出现黑屏了。具体原因我想的是因为在surfaceView中用线程不停的绘图，操作太频繁了，原来那种方法没有办法截出来。在surfaceView中绘图的原理：

用另外一个Canvas对象不停的把要画到surfaceView中的对象画到这个额外的canvas中，再声明一个Bitmap bitmap对象，注意这个bitmap不是你画在surfaceView中的对象，而是你的目标对象，就是需要截的图。你只需要这样：Canvas canvas=new Canvas(bitmap)，接着用canvas.drawBitmap(curBitmap, 0, 0, null),你就可以把当前的的要画的到SurfaceView保存到bitmap中，然后把bitmap保存出来就可以了。PS：这只是截出来SurfaceView中图像，如果想截取背景图片，可以把surfaceView设置为透明。网上有很多种方法，这里就不介绍了。

贴出网上可以运行的代码：

menu.xml:

Element.java

import android.content.res.Resources;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.graphics.Canvas;

public class Element {

private float mX;

private float mY;

private Bitmap mBitmap;

public Element(Resources res, int x, int y) {

mBitmap = BitmapFactory.decodeStream(new BufferedInputStream(res.openRawResource(R.drawable.icon)));

mX = x - mBitmap.getWidth() / 2;

mY = y - mBitmap.getHeight() / 2;

}

public void doDraw(Canvas canvas) {

canvas.drawBitmap(mBitmap, mX, mY, null);

}

}

Panel.java

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.util.ArrayList;

import android.content.Context;

import android.graphics.Bitmap;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.os.Environment;

import android.util.Log;

import android.view.MotionEvent;

import android.view.SurfaceHolder;

import android.view.SurfaceView;

public class Panel extends SurfaceView implements SurfaceHolder.Callback

{

public static float mWidth;

public static float mHeight;

private ViewThread mThread;

private ArrayList mElements = new ArrayList();

private int mElementNumber = 0;

private Paint mPaint = new Paint();

private String mScreenshotPath = Environment.getExternalStorageDirectory()

+ "/droidnova";

public Panel(Context context)

{

super(context);

getHolder().addCallback(this);

mThread = new ViewThread(this);

mPaint.setColor(Color.WHITE);

}

@Override

public void surfaceChanged(SurfaceHolder holder, int format, int width,

int height)

{

mWidth = width;

mHeight = height;

}

@Override

public void surfaceCreated(SurfaceHolder holder)

{

if (!mThread.isAlive())

{

mThread = new ViewThread(this);

mThread.setRunning(true);

mThread.start();

}

}

@Override

public void surfaceDestroyed(SurfaceHolder holder)

{

if (mThread.isAlive())

{

mThread.setRunning(false);

}

}

@Override

public boolean onTouchEvent(MotionEvent event)

{

synchronized (mElements)

{

mElements.add(new Element(getResources(), (int) event.getX(),

(int) event.getY()));

mElementNumber = mElements.size();

}

return super.onTouchEvent(event);

}

/**

* If called, creates a screenshot and saves it as a JPG in the folder

* "droidnova" on the sdcard.

*/

//在surfaceView上不停的绘图

public void doDraw(long elapsed, Canvas canvas)

{

canvas.drawColor(Color.BLACK);

synchronized (mElements)

{

for (Element element : mElements)

{

element.doDraw(canvas);

}

}

canvas.drawText("FPS: " + Math.round(1000f / elapsed) + " Elements: "

+ mElementNumber, 10, 10, mPaint);

}

public void saveScreenshot()

{

if (ensureSDCardAccess())

{

Bitmap bitmap = Bitmap.createBitmap(getWidth(), getHeight(),

Bitmap.Config.ARGB_8888);

Canvas canvas = new Canvas(bitmap);

//在surfaceView上不停的绘图

doDraw(1, canvas);

File file = new File(mScreenshotPath + "/"

+ System.currentTimeMillis() + ".jpg");

FileOutputStream fos;

try

{

fos = new FileOutputStream(file);

bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);

fos.close();

}

catch (FileNotFoundException e)

{

Log.e("Panel", "FileNotFoundException", e);

}

catch (IOException e)

{

Log.e("Panel", "IOEception", e);

}

}

}

/**

* Helper method to ensure that the given path exists. TODO: check external

* storage state

*/

private boolean ensureSDCardAccess()

{

File file = new File(mScreenshotPath);

if (file.exists())

{

return true;

}

else if (file.mkdirs())

{

return true;

}

return false;

}

}

ScreenshotActivity.java

import android.app.Activity;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuInflater;

import android.view.MenuItem;

import android.view.Window;

public class ScreenshotActivity extends Activity {

private Panel mPanel;

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

requestWindowFeature(Window.FEATURE_NO_TITLE);

mPanel = new Panel(this);

setContentView(mPanel);

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

MenuInflater inflater = getMenuInflater();

inflater.inflate(R.menu.menu, menu);

return true;

}

@Override

public boolean onOptionsItemSelected(MenuItem item) {

switch (item.getItemId()) {

case R.id.screenshot:

mPanel.saveScreenshot();

break;

}

return true;

}

}

ViewThread.java

import android.graphics.Canvas;

import android.view.SurfaceHolder;

public class ViewThread extends Thread {

private Panel mPanel;

private SurfaceHolder mHolder;

private boolean mRun = false;

private long mStartTime;

private long mElapsed;

public ViewThread(Panel panel) {

mPanel = panel;

mHolder = mPanel.getHolder();

}

public void setRunning(boolean run) {

mRun = run;

}

@Override

public void run() {

Canvas canvas = null;

mStartTime = System.currentTimeMillis();

while (mRun) {

canvas = mHolder.lockCanvas();

if (canvas != null) {

mPanel.doDraw(mElapsed, canvas);

mElapsed = System.currentTimeMillis() - mStartTime;

mHolder.unlockCanvasAndPost(canvas);

}

mStartTime = System.currentTimeMillis();

}

}

}

其实这很好理解。由于我的代码写在整个项目中，跌出来比较麻烦，就贴了一个以可以完整通过的工程。

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在 2012年LinuxIDC.com\7月\Android中截图(surfaceView)源码

关于截屏，暂时我的需求已经满足了，不知道这符合其他情况么？欢迎有兴趣的人一起交流。