Android mapview（negative coloring）

Question

我想在我的android應用程序中繪製一個圓形覆蓋圖，我當然可以輕鬆地做，併爲其添加顏色。

但我真正想做的是保持圓形透明，並以淺灰色遮住圓圈（世界其他地方）的外部。

我試圖添加圓作爲一個路徑，陰影世界和剪出圓圈，但我得到一個圍繞我的設備上的圓周邊框（雖然它看起來很好的模擬器）。

任何幫助表示讚賞。下面是一個代碼片段：

public void draw（Canvas canvas，MapView mapView，boolean shadow） super.draw（canvas，mapView，shadow）;

Projection projection = mapView.getProjection(); 

    Point pt = new Point(); 

    GeoPoint geo = new GeoPoint((int) (mLat * 1e6), (int) (mLon * 1e6)); 

    projection.toPixels(geo, pt); 
    float circleRadius = projection.metersToEquatorPixels(mRadius) 
      * (1/FloatMath.cos((float) Math.toRadians(mLat))); 

    Paint innerCirclePaint; 

    innerCirclePaint = new Paint(); 
    innerCirclePaint.setColor(Color.TRANSPARENT); 
    innerCirclePaint.setAlpha(35); 
    innerCirclePaint.setAntiAlias(true); 
    innerCirclePaint.setStyle(Paint.Style.FILL); 

    Path path = new Path(); 
    path.setFillType(Path.FillType.WINDING); 
    path.addCircle((float) pt.x, (float) pt.y, circleRadius, Path.Direction.CCW);canvas.drawPath(path, innerCirclePaint); 
    canvas.drawARGB(150, 0, 0, 0); 
    canvas.clipPath(path); 
} 

Answer 1

paint.setColor(Color.parseColor ("#88ff0000")); 

Answer 2

嘗試

path.setFillType(Path.FillType.INVERSE_WINDING); 

，而不是

path.setFillType(Path.FillType.WINDING); 

我嘗試了一個正常的形象，這個補丁爲我工作

Canvas canvas = new Canvas(bitmap); 
    Paint innerCirclePaint; 

    innerCirclePaint = new Paint(); 
    innerCirclePaint.setColor(Color.parseColor ("#88ff0000")); 
    innerCirclePaint.setAlpha(35); 
    innerCirclePaint.setAntiAlias(true); 
    innerCirclePaint.setStyle(Paint.Style.FILL); 

    Path path = new Path(); 
    path.setFillType(Path.FillType.INVERSE_WINDING); 
    path.addCircle(150, 150, 150, Path.Direction.CCW); 

    canvas.drawPath(path, innerCirclePaint); 
    canvas.drawARGB(0, 0, 0, 0); 
    canvas.clipPath(path); 

即使clipPath可能是一個原因

Work around Canvas.clipPath() that is not supported in android any more