android - 在Image View android上绘图

每当从另一个ImageView接收到像素值（要绘制的圆的中心）时，有人能帮助我在Activity上绘制一个特定半径的圆吗？

最佳答案

extendImageView和overrideonDraw(Canvas c)方法-addc.drawCirle(x,y,radius,Paint)
或者画圆也可以用纯帆布。
我试过这种方法，但还是不走运

public class MyActivity extends Activity {
private MyImageView myImageView;
 float x, y;
 float [] loc;
float radius = 50;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_show_location);
    myImageView = (MyImageView) findViewById(R.id.mapimageView);
    myImageView.setImageResource(R.drawable.mymap);

    //Receiving location information(x/y pixels array) from myLocation Activity
        Intent i = getIntent();
        loc = i.getFloatArrayExtra("Location");

}
public class MyImageView extends ImageView
{

    public MyImageView(Context context) {
        super(context);
    }
    // Constructor for inflating via XML
   public MyImageView(Context context, AttributeSet attrs) {
   super(context, attrs);
    }


            @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        Paint p = new Paint();
        x= loc[0];
        y=loc[1];
        p.setColor(Color.RED);
        p.setStrokeWidth(2);
        canvas.drawCircle(x, y, radius, p);
    }
}

在xml中，将<ImageView更改为your.package.name.MyImageView
//edit im只从memmory写入，所以可能会有拼写错误