Android中SurfaceView截屏

package com.droidnova.android.tutorial.screenshot; 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<Element> mElements = new ArrayList<Element>(); 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); } 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); } @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. */ public void saveScreenshot() { if (ensureSDCardAccess()) { Bitmap bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(bitmap); 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; } }