Android 自定义View实现单击和双击事件

自定义View,

1. 自定义一个Runnable线程TouchEventCountThread ,  用来统计500ms内的点击次数

2. 在MyView中的 onTouchEvent 中调用 上面的线程

3. 自定义一个Handler, 在TouchEventHandler 中 处理 统计到的点击事件, 单击, 双击, 三击, 都可以处理

核心代码如下:

public class MyView extends View {

   ......

    // 统计500ms内的点击次数
    TouchEventCountThread mInTouchEventCount = new TouchEventCountThread();
    // 根据TouchEventCountThread统计到的点击次数, perform单击还是双击事件
    TouchEventHandler mTouchEventHandler = new TouchEventHandler();

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                if (0 == mInTouchEventCount.touchCount) // 第一次按下时,开始统计
                    postDelayed(mInTouchEventCount, 500);
                break;
            case MotionEvent.ACTION_UP:
                // 一次点击事件要有按下和抬起, 有抬起必有按下, 所以只需要在ACTION_UP中处理
                mInTouchEventCount.touchCount++;
                // 如果是长按操作, 则Handler的消息,不能将touchCount置0, 需要特殊处理
                if(mInTouchEventCount.isLongClick) {
                    mInTouchEventCount.touchCount = 0;
                    mInTouchEventCount.isLongClick = false;
                }
                break;
            case MotionEvent.ACTION_MOVE:
                break;
            case MotionEvent.ACTION_CANCEL:
                break;
            default:
                break;
        }

        return super.onTouchEvent(event);
    }

    public class TouchEventCountThread implements Runnable {
        public int touchCount = 0;
        public boolean isLongClick = false;

        @Override
        public void run() {
            Message msg = new Message();
            if(0 == touchCount){ // long click
                isLongClick = true;
            } else {
                msg.arg1 = touchCount;
                mTouchEventHandler.sendMessage(msg);
                touchCount = 0;
            }
        }
    }

    public class TouchEventHandler extends Handler {

        @Override
        public void handleMessage(Message msg) {
            Toast.makeText(mContext, "touch " + msg.arg1 + " time.", Toast.LENGTH_SHORT).show();
        }
    }

    ......

}

包装以后如下, 这样就能在别的地方调用了:

    public interface OnDoubleClickListener{
        void onDoubleClick(View v);
    }

    private OnDoubleClickListener mOnDoubleClickListener;

    public void setOnDoubleClickListener(MyView.OnDoubleClickListener l) {
        mOnDoubleClickListener = l;
    }

    public boolean performDoubleClick() {
        boolean result = false;
        if(mOnDoubleClickListener != null) {
            mOnDoubleClickListener.onDoubleClick(this);
            result = true;
        }
        return result;
    }

    public class TouchEventHandler extends Handler {

        @Override
        public void handleMessage(Message msg) {
            if(2 == msg.arg1)
                performDoubleClick();
        }
    }

在Activity中使用:

        myView1.setOnDoubleClickListener(new MyView.OnDoubleClickListener() {
            @Override
            public void onDoubleClick(View v) {
                Toast.makeText(mContext,"double click", Toast.LENGTH_SHORT).show();
            }
        });

全部代码

MyView.java

package com.carloz.test.myapplication.view;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Toast;

import com.carloz.test.myapplication.R;

/**
 * Created by root on 15-11-9.
 */
public class MyView extends View {

    private Paint mPaint = new Paint();
    private boolean mNotDestroy = true;
    private int mCount = 0;
    private MyThread myThread;
    Bitmap bitmap;
    // attrs
    private String mText;
    private boolean mStartChange;
    Context mContext;

    public MyView(Context context) {
        super(context);
        init();
    }

    public MyView(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.MyView);
        mText = ta.getString(R.styleable.MyView_text);
        mStartChange = ta.getBoolean(R.styleable.MyView_startChange, false);
        // Log.d("ASDF", "mText=" + mText + ", mStartChange=" + mStartChange);
        ta.recycle();

        init();
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        mPaint.setTextSize(50);
        canvas.drawText(mText + mCount++, 20f, 100f, mPaint);
        canvas.save();
        canvas.rotate(60, getWidth() / 2, getHeight() / 2);
        canvas.drawBitmap(bitmap, 20f, 50f, mPaint);
        canvas.restore();

        if (null == myThread) {
            myThread = new MyThread();
            myThread.start();
        }
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        return super.dispatchTouchEvent(ev);
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        mNotDestroy = true;
    }

    @Override
    protected void onDetachedFromWindow() {
        mNotDestroy = false;
        super.onDetachedFromWindow();
    }

    // 统计500ms内的点击次数
    TouchEventCountThread mInTouchEventCount = new TouchEventCountThread();
    // 根据TouchEventCountThread统计到的点击次数, perform单击还是双击事件
    TouchEventHandler mTouchEventHandler = new TouchEventHandler();

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                if (0 == mInTouchEventCount.touchCount) // 第一次按下时,开始统计
                    postDelayed(mInTouchEventCount, 500);
                break;
            case MotionEvent.ACTION_UP:
                // 一次点击事件要有按下和抬起, 有抬起必有按下, 所以只需要在ACTION_UP中处理
                mInTouchEventCount.touchCount++;
                // 如果是长按操作, 则Handler的消息,不能将touchCount置0, 需要特殊处理
                if(mInTouchEventCount.isLongClick) {
                    mInTouchEventCount.touchCount = 0;
                    mInTouchEventCount.isLongClick = false;
                }
                break;
            case MotionEvent.ACTION_MOVE:
                break;
            case MotionEvent.ACTION_CANCEL:
                break;
            default:
                break;
        }

        return super.onTouchEvent(event);
    }

    public class TouchEventCountThread implements Runnable {
        public int touchCount = 0;
        public boolean isLongClick = false;

        @Override
        public void run() {
            Message msg = new Message();
            if(0 == touchCount){ // long click
                isLongClick = true;
            } else {
                msg.arg1 = touchCount;
                mTouchEventHandler.sendMessage(msg);
                touchCount = 0;
            }
        }
    }

    public class TouchEventHandler extends Handler {

        @Override
        public void handleMessage(Message msg) {
            Toast.makeText(mContext, "touch " + msg.arg1 + " time.", Toast.LENGTH_SHORT).show();
        }
    }

    class MyThread extends Thread {

        @Override
        public void run() {
            super.run();
            while (mNotDestroy) {
                if (mStartChange) {
                    postInvalidate();
                    try {
                        Thread.sleep(500);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
    }

    public void init() {
        mContext = getContext();
        bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
    }

    public void setText(String mText) {
        this.mText = mText;
    }

    public void setStartChange(boolean mStartChange) {
        this.mStartChange = mStartChange;
    }

    public boolean getStartChange() {
        return this.mStartChange;
    }
}

attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="MyView">
        <attr name="text" format="string"/>
        <attr name="startChange" format="boolean"/>
    </declare-styleable>

</resources>

postDelayed方法最终是靠 Handler 的 postDelayed 方法 实现原理如下

    public final boolean postDelayed(Runnable r, long delayMillis)
    {
        return sendMessageDelayed(getPostMessage(r), delayMillis);
    }

    public final boolean sendMessageDelayed(Message msg, long delayMillis)
    {
        if (delayMillis < 0) {
            delayMillis = 0;
        }
        return sendMessageAtTime(msg, SystemClock.uptimeMillis() + delayMillis);
    }

    public boolean sendMessageAtTime(Message msg, long uptimeMillis) {
        MessageQueue queue = mQueue;
        if (queue == null) {
            RuntimeException e = new RuntimeException(
                    this + " sendMessageAtTime() called with no mQueue");
            Log.w("Looper", e.getMessage(), e);
            return false;
        }
        return enqueueMessage(queue, msg, uptimeMillis);  // 然后在MessageQueue中会比较时间顺序
    }