Question

我正在为Android佩戴开发Watch Face。我想让Canvas硬件加速。

在清单中我声明它像吼叫

     <application
         android:hardwareAccelerated="true"
         ..>
            <service
            android:name=".WatchFaceMain"
            android:hardwareAccelerated="true"
            ..>
    </application>

但是当我从My onDraw（Canvas canvas，Rect bounds）内部检查它时，canvas.isHardwareAccelerated（）返回false。这显然意味着我的画布不是硬件加速的。

 @Override
 public void onDraw(Canvas canvas, Rect bounds) {
       ...
       boolean isAccelarated = canvas.isHardwareAccelerated();
       .......
 }

如何使此画布硬件加速？

Answer 1

终于找到了解决这个问题的方法。虽然这不是一个直接或简单的解决方案。

首先，我从librar复制整个android.support.wearable.watchface.CanvasWatchFaceService类，我的WatchFaceMain类扩展了它。

然后我必须编辑Engine类中的draw（）方法，如bellow

public abstract class CanvasWatchFaceService extends WatchFaceService {
    .....

        public class Engine extends android.support.wearable.watchface.WatchFaceService.Engine {
          ...
            private void draw(SurfaceHolder holder) {
                this.mDrawRequested = false;
                Canvas canvas = holder.getSurface().lockHardwareCanvas();
                if(canvas != null) {
                    try {
                        this.onDraw(canvas, holder.getSurfaceFrame());
                    } finally {
                        holder.getSurface().unlockCanvasAndPost(canvas);
                    }

                }
            }
        }
    }

我在onDraw中编辑了两行，如下所述。

from
 Canvas canvas = holder.lockCanvas();
To
 Canvas canvas = holder.getSurface().lockHardwareCanvas();

And From
 holder.unlockCanvasAndPost(canvas);
To
 holder.getSurface().unlockCanvasAndPost(canvas);

我仍然想知道为什么CanvasWatchFaceService没有提供任何更简单的方法来请求硬件加速画布！

More detail solution is available here in this Article.

希望这个答案对其他人也有帮助。

如何在CanvasWatchFaceService的onDraw（）中获得硬件加速Canvas？

1 个答案: