Android自定义view的点击事件

package com.bwie.test.custom_textview;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

import java.util.Random;
public class MyTextView extends View {
    /**
     * 需要绘制的文字
     */
    private String mText;
    /**
     * 文本的颜色
     */
    private int mTextColor;
    /**
     * 文本的大小
     */
    private float mTextSize;
    /**
     * 绘制时控制文本绘制的范围
     */
    private Rect mBound;
    private Paint mPaint;

    public MyTextView(Context context) {
        this(context, null);
    }

    public MyTextView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public MyTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        //获取自定义属性的值
        TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.MyTextView, defStyleAttr, 0);
        mText = a.getString(R.styleable.MyTextView_mText);
        mTextColor = a.getColor(R.styleable.MyTextView_mTextColor, Color.BLACK);
        mTextSize = a.getDimension(R.styleable.MyTextView_mTextSize, 100);
        a.recycle();  //注意回收
        mPaint = new Paint();
        mPaint.setTextSize(mTextSize);
        mPaint.setColor(mTextColor);
        //获得绘制文本的宽和高
        mBound = new Rect();
        mPaint.getTextBounds(mText, 0, mText.length(), mBound);
    }
    @Override
    protected void onDraw(Canvas canvas) {
        //绘制文字
        canvas.drawText(mText, getWidth() / 2 - mBound.width() / 2, getHeight() / 2 + mBound.height() / 2, mPaint);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()){
            case MotionEvent.ACTION_MOVE:
            case MotionEvent.ACTION_DOWN:
                //获取屏幕上点击的坐标
                float x=event.getX();
                float y = event.getY();
                //如果坐标在我们的文字区域内，则将点击的文字改颜色
                Random ran=new Random();
                int i = ran.nextInt(1000)+1000;
                mText=i+"";
                invalidate();
                break;
            case MotionEvent.ACTION_UP:
                //点击抬起后，回复初始位置。
                invalidate();//更新视图
                return true;
        }
        //这句话不要修改
        return super.onTouchEvent(event);
    }
}