系统截屏源码

frameworks\base\packages\SystemUI\src\com\android\systemui\screenshot

takeScreenshot方法

// We need to orient the screenshot correctly (and the Surface api seems to take screenshots// only in the natural orientation of the device :!)mDisplay.getRealMetrics(mDisplayMetrics);float[] dims &＃61; {mDisplayMetrics.widthPixels, mDisplayMetrics.heightPixels};float degrees &＃61; getDegreesForRotation(mDisplay.getRotation());boolean requiresRotation &＃61; (degrees > 0);if (requiresRotation) {// Get the dimensions of the device in its native orientationmDisplayMatrix.reset();mDisplayMatrix.preRotate(-degrees);mDisplayMatrix.mapPoints(dims);dims[0] &＃61; Math.abs(dims[0]);dims[1] &＃61; Math.abs(dims[1]);}// Take the screenshotmScreenBitmap &＃61; SurfaceControl.screenshot((int) dims[0], (int) dims[1]);if (mScreenBitmap &＃61;&＃61; null) {notifyScreenshotError(mContext, mNotificationManager);finisher.run();return;}if (requiresRotation) {// Rotate the screenshot to the current orientationBitmap ss &＃61; Bitmap.createBitmap(mDisplayMetrics.widthPixels,mDisplayMetrics.heightPixels, Bitmap.Config.ARGB_8888);Canvas c &＃61; new Canvas(ss);c.translate(ss.getWidth() / 2, ss.getHeight() / 2);c.rotate(degrees);c.translate(-dims[0] / 2, -dims[1] / 2);c.drawBitmap(mScreenBitmap, 0, 0, null);c.setBitmap(null);// Recycle the previous bitmapmScreenBitmap.recycle();mScreenBitmap &＃61; ss;}// OptimizationsmScreenBitmap.setHasAlpha(false);mScreenBitmap.prepareToDraw();// Start the post-screenshot animationstartAnimation(finisher, mDisplayMetrics.widthPixels, mDisplayMetrics.heightPixels,statusBarVisible, navBarVisible);

  // Take the screenshot
        mScreenBitmap &＃61; SurfaceControl.screenshot((int) dims[0], (int) dims[1]);

主要还是这一句也就是SurfaceControl.screenshot();

所以我们也可以调用反射调用

//使用反射调用截屏private void screenShotByReflect(){DisplayMetrics mDisplayMetrics &＃61; new DisplayMetrics();float[] dims &＃61; { mDisplayMetrics.widthPixels,mDisplayMetrics.heightPixels };try {Class demo &＃61; Class.forName("android.view.SurfaceControl");Method method &＃61; demo.getDeclaredMethod("screenshot", int.class,int.class);mScreenBitmap &＃61; (Bitmap) method.invoke(null,(int) dims[0],(int) dims[1]);} catch (Exception e) {e.printStackTrace();}}

因为这部分代码是在setting里的&＃xff0c;可能是需要系统签名的&＃xff0c;我自己试了一下&＃xff0c;没有系统签名是不成功的。