自定义view重写触摸事件-imageview为例

最新推荐文章于 2021-05-27 22:29:41 发布

原创最新推荐文章于 2021-05-27 22:29:41 发布 · 1.9k 阅读

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本文深入探讨了如何在Android中为自定义View重写触摸事件，以ImageView为例，详细解释了如何捕获和处理触摸事件，包括ACTION_DOWN、ACTION_MOVE和ACTION_UP等，帮助开发者实现更丰富的交互效果。

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package com.bdyl.view;
import com.bdyl.constance.Logs;
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;

public class MyImage extends ImageView {
	private float mOldX;
	private float mOldY;
	private float mCurrentX;
	private float mCurrentY;
	private int state = -1;

	public static final int left = 1;
	public static final int right = 2;
	public static final int normal = 3;

	public MyImage(Context context, AttributeSet attrs) {
		super(context, attrs);
	}
	/*
	*重写触摸事件
	*/
	@Override
	public boolean onTouchEvent(MotionEvent event) {
		switch (event.getAction()) {
		// 按下
		case MotionEvent.ACTION_DOWN:
			mOldX = event.getX();
			mOldY = event.getY();
			state = normal;
			break;
		// 移动,根据坐标判断移动方向（偏移量是需要定义dimen，这里为了方便）
		case MotionEvent.ACTION_MOVE:
			mCurrentX = event.getX();
			mCurrentY = event.getY();
			if (mCurrentX - mOldX > 0 && Math.abs(mCurrentY - mOldY) < 10) {
				state = right;
				Logs.v("向右>>>>");
			}
			else if (mCurrentX - mOldX < 0
					&& Math.abs(mCurrentY - mOldY) < 10) {
				state = left;
				Logs.v("向向左>>>>");

			}
			else if (mCurrentY - mOldY > 0
					&& Math.abs(mCurrentX - mOldX) < 10) {

			}
			else if (mCurrentY - mOldY < 0
					&& Math.abs(mCurrentX - mOldX) < 10) {
			}
			break;
		// 释放
		case MotionEvent.ACTION_UP:
			switch (state) {
			case right:
				mMoveListener.last();
				Logs.v("向right up  ");
				break;
			case left:
				mMoveListener.next();
				Logs.v("向向左 up  ");
				break;
			case normal:
				mMoveListener.click();		
			break;
			}
			break;
		}
		return true;

	}
	private OnMovePicture mMoveListener;
	public void setOnMovePicture(OnMovePicture move){
		mMoveListener= move;
	}
	/*
	*左右滑动点击的回调接口
	*/
	public interface OnMovePicture{
		void next();
		void last();
		void click();
	}

}