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package com.ewebapps;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.view.View;

public class Dot extends View {
     private final float x;
     private final float y;
     private final int r;
     private final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
     private final Paint mWhite = new Paint(Paint.ANTI_ALIAS_FLAG);

     public Dot(Context context, float x, float y, int r) {
         super(context);
         mPaint.setColor(0xFF000000); //Black
         mWhite.setColor(0xFFFFFFFF); //White
         this.x = x;
         this.y = y;
         this.r = r;
     }

     @Override
     protected void onDraw(Canvas canvas) {
         super.onDraw(canvas);
         canvas.drawCircle(x, y, r+2, mWhite); //White stroke.
         canvas.drawCircle(x, y, r, mPaint); //Black circle.
     }

}
4

3 回答 3

1

好吧...在创建自己的视图时,最好的方法是覆盖该dispatchTouchEvent方法。相信我,在某些情况下使用setOnTouchListeneronTouchEvent不能很好地工作。这就是你在你的View

@Override
public boolean dispatchTouchEvent(MotionEvent event) {
    // put your logic here  

    return super.dispatchTouchEvent(event);
}
于 2010-11-02T01:26:45.223 回答
0

带有示例的文档

View aView = (View)findViewById(R.id.DotView);
aView.setOnTouchListener(this);

完整的例子在这里

于 2010-11-02T00:17:11.863 回答
0

Aaron Saunders 的答案适用于视图(如按钮),因为 onTouchListener 只告诉您单击了哪个视图,而不是确切的位置。如果您需要在不创建按钮的情况下确切知道事件的位置,请在您的活动类中尝试以下操作:

@Override onTouchEvent(MotionEvent event) { int _x = event.getX();
int _y = event.getY(); // do stuff }

注意:onTouchEvent 仅在事件未由视图处理时调用。
文档

有人可以告诉我如何添加换行符吗?

于 2010-11-02T01:16:33.760 回答