仿QQ滑动删除

柔光的暖阳◎ 2022-08-07 14:51 167阅读 0赞

思路就是利用一个PopupWindow来显示删除的按钮，通过PopupWindow对象来控制什么时候显示，什么时候删除。注意重写dispatchTouchEvent和TouchEvent两个方法。

先看删除Button的布局文件：

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical" >
        
    	<Button 
    	    android:id="@+id/btn_delete"
    	    android:layout_width="wrap_content"
    	    android:layout_height="wrap_content"
    	    android:singleLine="true"
    	    android:text="删除"
    	    android:background="@drawable/mm_title_back_pressed"/>
    </LinearLayout>

在看主页面：

主要看自定义的ListView

package com.drision.ui;
    
    import com.drision.listviewslip.R;
    
    import android.content.Context;
    import android.util.AttributeSet;
    import android.util.Log;
    import android.view.Gravity;
    import android.view.LayoutInflater;
    import android.view.MotionEvent;
    import android.view.View;
    import android.view.ViewConfiguration;
    import android.widget.Button;
    import android.widget.LinearLayout;
    import android.widget.ListView;
    import android.widget.PopupWindow;
    
    public class MyListView extends ListView {
    
    	private static final String TAG="MyListView";
    	/**
    	 * 用户滑动的最小距离
    	 */
    	private int touchSlop;
    	private boolean isSliding;
    	private int xDown;
    	private int yDown;
    	private int xMove;
    	private int yMove;
    	
    	private LayoutInflater inflater;
    	private PopupWindow popupWindow;
    	private int popupHeight;
    	private int popupWidth;
    	
    	private Button btn_delete;
    	//当前手指触摸的view
    	private View currentView;
    	private int currentPosition;
    	private DelButtonClickListener mListener;
    	//构造函数必须使用这个带attrs，不然报错，我也不晓得为什么，因为我很菜
    	public MyListView(Context context , AttributeSet attrs) {
    		super(context, attrs);
    		inflater = LayoutInflater.from(context);
    		touchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
    		View view = inflater.inflate(R.layout.delete_btn, null);
    		btn_delete = (Button) view.findViewById(R.id.btn_delete);
    		popupWindow = new PopupWindow(view, LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
    		/**
    		 * 调用measure，否则拿不到宽和高
    		 */
    		popupWindow.getContentView().measure(0, 0);
    		popupHeight = popupWindow.getContentView().getMeasuredHeight();
    		popupWidth = popupWindow.getContentView().getMeasuredWidth();
    	}
    
    	@Override
    	public boolean onTouchEvent(MotionEvent ev) {
    		int action = ev.getAction();
    		//从右到左滑动
    		if(isSliding){
    			switch(action){
    			case MotionEvent.ACTION_MOVE:
    				int [] location = new int [2];
    				//获取当前item的位置
    				currentView.getLocationOnScreen(location);
    				//设置popup的动画
    				popupWindow.setAnimationStyle(R.style.popwindow_delete_btn_anim_style);
    				popupWindow.update();
    				popupWindow.showAtLocation(currentView, Gravity.LEFT | Gravity.TOP,
    						location[0] + currentView.getWidth(), location[1] + currentView.getHeight() / 2
    								- popupHeight / 2);
    				btn_delete.setOnClickListener(new OnClickListener(){
    
    					@Override
    					public void onClick(View v) {
    						if(mListener != null){
    							mListener.clickHappend(currentPosition);
    							popupWindow.dismiss();
    						}
    					}
    				});
    				break;
    			case MotionEvent.ACTION_UP:  
                    isSliding = false; 
                    break;
    			}
    			return true; 
    		}
    		return super.onTouchEvent(ev);
    	}
    
    	@Override
    	public boolean dispatchTouchEvent(MotionEvent ev) {
    		int action = ev.getAction();
    		int x = (int) ev.getX();
    		int y = (int) ev.getY();
    		switch(action){
    		case MotionEvent.ACTION_DOWN:
    			xDown = x;
    			yDown = y;
    			//如果popup显示
    			if (popupWindow.isShowing())
    			{
    				dismissPopWindow();
    				return false;
    			}
    			
    			//获取当前手指按下的item的位置
    			currentPosition = pointToPosition(xDown, yDown);
    			//获取当前的item
    			View view = getChildAt(currentPosition - getFirstVisiblePosition());
    			currentView = view;
    			break;
    		case MotionEvent.ACTION_MOVE:
    			xMove = x;
    			yMove= y;
    			int dx = xMove - xDown;
    			int dy = yMove - yDown;
    			
    			//判断是否从右向左滑动
    			if(xMove < xDown && Math.abs(dx) > touchSlop && Math.abs(dy)< touchSlop){
    				isSliding = true;
    			}
    			break;
    		}
    		return super.dispatchTouchEvent(ev);
    	}
    
    	private void dismissPopWindow()
    	{
    		if (popupWindow != null && popupWindow.isShowing())
    		{
    			popupWindow.dismiss();
    		}
    	}
    	public void setDelButtonClickListener(DelButtonClickListener listener){  
             mListener = listener;  
         }  
    	  
        public interface DelButtonClickListener {  
            public void clickHappend(int position);  
        }  
    	
    
    }

看两个动画的定义：

delete\_btn\_hide.xml

<?xml version="1.0" encoding="utf-8"?>
    
    <set xmlns:android="http://schemas.android.com/apk/res/android">
    
    <scale  android:interpolator="@android:anim/accelerate_decelerate_interpolator"
    
              android:fromXScale="1.0"
              android:toXScale="0.0"
              android:fromYScale="1.0"
              android:toYScale="1.0"
              android:pivotX="100%"
              android:pivotY="50%"
              android:fillAfter="false"
              android:duration="200" >
    </scale>
    
    </set>

delete\_btn\_show.xml

<?xml version="1.0" encoding="utf-8"?>
    
    <set xmlns:android="http://schemas.android.com/apk/res/android">
    
    <scale  android:interpolator="@android:anim/accelerate_decelerate_interpolator"
    
              android:fromXScale="0.0"
              android:toXScale="1.0"
              android:fromYScale="1.0"
              android:toYScale="1.0"
              android:pivotX="100%"
              android:pivotY="50%"
              android:fillAfter="false"
              android:duration="200" >
    
     
    </scale>
    
    </set>

在看主Activity：

package com.drision.listviewslip;
    
    import java.util.ArrayList;
    import java.util.Arrays;
    import java.util.List;
    
    import com.drision.ui.MyListView.DelButtonClickListener;
    import com.drision.ui.MyListView;
    
    import android.app.Activity;
    import android.os.Bundle;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.view.View;
    import android.widget.AdapterView;
    import android.widget.AdapterView.OnItemClickListener;
    import android.widget.ArrayAdapter;
    import android.widget.Toast;
    
    public class MainActivity extends Activity {
    
    	private MyListView listView;
    	private ArrayAdapter adapter;
    	private List<String> datas;
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.activity_main);
    		listView = (MyListView) this.findViewById(R.id.listView1);
    		datas = new ArrayList<String>(Arrays.asList("HelloWorld", "Welcome", "Java", "Android", "Servlet", "Struts",  
                    "Hibernate", "Spring", "HTML5", "Javascript", "Lucene"));
    		adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, datas);
    		listView.setAdapter(adapter);
    		listView.setDelButtonClickListener(new DelButtonClickListener() {
    			public void clickHappend(int position) {
    				Toast.makeText(MainActivity.this, position + " : " + adapter.getItem(position), 1).show(); 
    				return;
    			}
    		});
    		listView.setOnItemClickListener(new OnItemClickListener(){
    			@Override
    			public void onItemClick(AdapterView<?> parent, View view,
    					int position, long id) {
    				 Toast.makeText(MainActivity.this, position + " : " + adapter.getItem(position), 1).show();  
    			}
    		});;
    	}
    }