Canvas.clipPath上的Android UnsupportedOperationException异常

我正在使用我的项目中的 https://github.com/lvillani/android-cropimage的图像裁剪库来裁剪存储在设备上的图像.

但是,某些用户正在使用以下堆栈跟踪来报告崩溃

java.lang.UnsupportedOperationException
at android.view.GLES20Canvas.clipPath(GLES20Canvas.java:413)
at com.android.camera.HighlightView.draw(HighlightView.java:101)
at com.android.camera.CropImageView.onDraw(CropImage.java:783)
at android.view.View.draw(View.java:11006)
at android.view.View.getDisplayList(View.java:10445)
at android.view.ViewGroup.drawChild(ViewGroup.java:2850)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.getDisplayList(View.java:10443)
at android.view.ViewGroup.drawChild(ViewGroup.java:2850)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.getDisplayList(View.java:10443)
at android.view.ViewGroup.drawChild(ViewGroup.java:2850)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.getDisplayList(View.java:10443)
at android.view.ViewGroup.drawChild(ViewGroup.java:2850)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.getDisplayList(View.java:10443)
at android.view.ViewGroup.drawChild(ViewGroup.java:2850)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:11009)
at android.widget.FrameLayout.draw(FrameLayout.java:450)
at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:2154)
at android.view.View.getDisplayList(View.java:10445)
at android.view.HardwareRenderer$GlRenderer.draw(HardwareRenderer.java:853)
at android.view.ViewRootImpl.draw(ViewRootImpl.java:1961)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1679)
at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2558)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4697)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:787)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:554)
at dalvik.system.NativeStart.main(Native Method)

从搜索我认为这是由某些设备上的硬件加速引起的.我的清单中禁用了硬件加速,但异常仍然发生.我还发现“一个固定的解决方法是识别代码中的有问题的操作,将它们绘制到位图,然后将位图打到加速的画布上.

根据堆栈跟踪的有问题的代码是

protected void draw(Canvas canvas) {
    if (mHidden) {
        return;
    }
    canvas.save();
    Path path = new Path();
    if (!hasFocus()) {
        mOutlinePaint.setColor(0xFF000000);
        canvas.drawRect(mDrawRect,mOutlinePaint);
    } else {
        Rect viewDrawingRect = new Rect();
        mContext.getDrawingRect(viewDrawingRect);
        if (mCircle) {
            float width  = mDrawRect.width();
            float height = mDrawRect.height();
            path.addCircle(mDrawRect.left + (width  / 2),mDrawRect.top + (height / 2),width / 2,Path.Direction.CW);
            mOutlinePaint.setColor(0xFFEF04D6);
        } else {
            path.addRect(new RectF(mDrawRect),Path.Direction.CW);
            mOutlinePaint.setColor(0xFFFF8A00);
        }
        canvas.clipPath(path,Region.Op.DIFFERENCE);
        canvas.drawRect(viewDrawingRect,hasFocus() ? mFocusPaint : mNoFocusPaint);

        canvas.restore();
        canvas.drawPath(path,mOutlinePaint);

        if (mMode == ModifyMode.Grow) {
            if (mCircle) {
                int width  = mResizeDrawableDiagonal.getIntrinsicWidth();
                int height = mResizeDrawableDiagonal.getIntrinsicHeight();

                int d  = (int) Math.round(Math.cos(/*45deg*/Math.PI / 4D)
                        * (mDrawRect.width() / 2D));
                int x  = mDrawRect.left
                        + (mDrawRect.width() / 2) + d - width / 2;
                int y  = mDrawRect.top
                        + (mDrawRect.height() / 2) - d - height / 2;
                mResizeDrawableDiagonal.setBounds(x,y,x + mResizeDrawableDiagonal.getIntrinsicWidth(),y + mResizeDrawableDiagonal.getIntrinsicHeight());
                mResizeDrawableDiagonal.draw(canvas);
            } else {
                int left    = mDrawRect.left   + 1;
                int right   = mDrawRect.right  + 1;
                int top     = mDrawRect.top    + 4;
                int bottom  = mDrawRect.bottom + 3;

                int widthWidth   =
                        mResizeDrawableWidth.getIntrinsicWidth() / 2;
                int widthHeight  =
                        mResizeDrawableWidth.getIntrinsicHeight() / 2;
                int heightHeight =
                        mResizeDrawableHeight.getIntrinsicHeight() / 2;
                int heightWidth  =
                        mResizeDrawableHeight.getIntrinsicWidth() / 2;

                int xMiddle = mDrawRect.left
                        + ((mDrawRect.right  - mDrawRect.left) / 2);
                int yMiddle = mDrawRect.top
                        + ((mDrawRect.bottom - mDrawRect.top) / 2);

                mResizeDrawableWidth.setBounds(left - widthWidth,yMiddle - widthHeight,left + widthWidth,yMiddle + widthHeight);
                mResizeDrawableWidth.draw(canvas);

                mResizeDrawableWidth.setBounds(right - widthWidth,right + widthWidth,yMiddle + widthHeight);
                mResizeDrawableWidth.draw(canvas);

                mResizeDrawableHeight.setBounds(xMiddle - heightWidth,top - heightHeight,xMiddle + heightWidth,top + heightHeight);
                mResizeDrawableHeight.draw(canvas);

                mResizeDrawableHeight.setBounds(xMiddle - heightWidth,bottom - heightHeight,bottom + heightHeight);
                mResizeDrawableHeight.draw(canvas);
            }
        }
    }
}

我如何绘制一个位图然后blit到画布？

任何帮助将不胜感激！

解决方法

在ICS设备上,即使应用程序没有请求硬件加速,也有一个开发者选项.那就是造成崩溃的原因.您应该可以使用这样的东西来强制它使用软件渲染：

if (Build.VERSION.SDK_INT > Build.VERSION_CODES.HONEYCOMB) {
   myCusomView.setLayerType(View.LAYER_TYPE_SOFTWARE,null);
}