如何将画布点转换为地图坐标

Question

I am drawing a shape on the map. Actually, I am using a View on a map to draw a shape. I brought this View to front on some button click. So, map is residing back to this View. I am able to draw a shape on the View using canvas. Now, I want these points to be converted to Map coordinates.

See this image,

It seems that drawing is done on the map. But the drawing is done on a transparent View. From these canvas Points, I want to translate to Map Coordinates.

I don't know how to achieve this. Please suggest me any idea of how to do this.

my code,

public boolean onTouch(View v, MotionEvent event) {     
    int action = event.getAction();
    path = new Path();
    float upX;
    float upY;
    Log.d("", "OnTouch");
    switch (action) {
    case MotionEvent.ACTION_DOWN:
        canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
        downx = event.getX();
        downy = event.getY();
        eventX = downx;
        eventY = downy;
        Log.d("", "startx" + eventX);
        break;
    case MotionEvent.ACTION_MOVE:
        upx = event.getX();
        upy = event.getY();
        canvas.drawLine(downx, downy, upx, upy, paint);
        drawable.invalidate();
        downx = upx;
        downy = upy;
        break;
    case MotionEvent.ACTION_UP:
        upX = event.getX();
        upY = event.getY();
        Log.d("", "Action Up");
        Log.d("", "endx" + upX);
        canvas.drawLine(eventX, eventY, upX, upY, paint);
        drawable.invalidate();
        return true;
    case MotionEvent.ACTION_CANCEL:
        break;
    default:
        break;

    }
    return true;
}

I want to perform some functinality in this area drawn by getting the N,E,W,S coordinates(map coordinates) from the drawing on the view. In which way I can modify my code. Please suggest me.

Please provide me any links if possible. Any help is appreciated!!

Answer 1

您想要的是Projection https://developers.google.com/maps/documentation/android/v1/reference/com/google/android/maps/Projection ，请问为什么在onTouch中在Canvas上绘制任何内容？