onTouchEvent

新建"MyView"类

package onTouchEvent;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.MotionEvent;
import android.view.View;

public class MyView extends View {
    private int textX=20,textY=20;
    public MyView(Context context) {
    super(context);
    setFocusable(true);
        // TODO Auto-generated constructor stub
    }
        //画笔onDraw方法
    @Override
    protected void onDraw(Canvas canvas) {
        // TODO Auto-generated method stub
        super.onDraw(canvas);
        //初始化画笔
        Paint paint=new Paint();
        //设置颜色
        paint.setColor(Color.GREEN);
        //设置字体大小
        paint.setTextSize(50);
        //在画布上写文字
        canvas.drawText("Android", textX, textY, paint);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        // TODO Auto-generated method stub
        //获取用户手指触屏的X坐标赋值与文本的X坐标
        textX=(int)event.getX();
        //获取用户手指触屏的Y坐标赋值与文本的Y坐标
        textY=(int)event.getY();
        //重绘画布
        invalidate();
        return true;

    }

}

MainActivity中将setContentView设置为当前MyView，即

setContentView(new MyView(this));

执行效果图如下：