這個問題百度上一搜一大把,基本上都是說找到和SurfaceView的比例相近的camera預覽尺寸,但是發現預覽時候還是差了點意思,具體看下面這個回調就知道是為什么了。
@Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { Log.i(TAG, "surfaceChanged: " + width + " " + height); }從上面的回調打印的數據知道其實取相近的比例解決不了根本問題。
所以,對于此類的解決方法我只想說僅僅相近有神馬用。
那么既然知道surfaceChanged的寬高就是SurfaceView的渲染寬高,那么想辦法把surfaceChanged里的寬高比弄成和camera比例一樣不就行了嘛,所以看SurfaceView的源碼:
protected void updateWindow(boolean force, boolean redrawNeeded) { ...代碼省略 int myWidth = mRequestedWidth; if (myWidth <= 0) myWidth = getWidth(); int myHeight = mRequestedHeight; if (myHeight <= 0) myHeight = getHeight(); ...代碼省略 if (creating || formatChanged || sizeChanged || visibleChanged || realSizeChanged) { if (DEBUG) Log.i(TAG, System.identityHashCode(this) + " " + "surfaceChanged -- format=" + mFormat + " w=" + myWidth + " h=" + myHeight); if (callbacks == null) { callbacks = getSurfaceCallbacks(); } for (SurfaceHolder.Callback c : callbacks) { c.surfaceChanged(mSurfaceHolder, mFormat, myWidth, myHeight); } } ...代碼省略 }可以看到寬高其實就是調用的View的getHeight和getWidth或者是mRequestedWidth和mRequestedHeight。
熟悉了View的自定義就知道getHeight和getWidth都是和View的onMeasure息息相關,所以想到重寫onMeasure方法。
再從源碼看到關于mRequestedWidth和mRequestedHeight的賦值
@Override public void setFixedSize(int width, int height) { if (mRequestedWidth != width || mRequestedHeight != height) { mRequestedWidth = width; mRequestedHeight = height; requestLayout(); } }以下是完整類代碼:
public class ResizeAbleSurfaceView extends SurfaceView { private int mWidth = -1; private int mHeight = -1; public ResizeAbleSurfaceView(Context context) { super(context); } public ResizeAbleSurfaceView(Context context, AttributeSet attrs) { super(context, attrs); } public ResizeAbleSurfaceView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { if (-1 == mWidth || -1 == mHeight) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); } else { setMeasuredDimension(mWidth, mHeight); } } public void resize(int width, int height) { mWidth = width; mHeight = height; getHolder().setFixedSize(width, height); requestLayout(); invalidate(); }}實例化的時候記得調用resize方法就好了。
注意和camera的預覽尺寸比例一致,且寬高記得傳正確,不然可能不全屏
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