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*********************************************跟上一篇效果一样***********************************
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity" > <com.example.listview.QQListView android:id="@+id/list" android:layout_width="wrap_content" android:layout_height="wrap_content" android:cacheColorHint="@android:color/transparent" android:listSelector="@android:color/transparent" android:divider="@android:color/darker_gray" android:dividerHeight="2dp" /> </RelativeLayout> item.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" > <TextView android:id="@+id/tv" android:layout_width="match_parent" android:layout_height="wrap_content" android:paddingBottom="20dp" android:paddingLeft="10dp" android:paddingTop="20dp" android:background="@android:color/white"/> <TextView android:id="@+id/delete" android:layout_width="80dp" android:layout_height="match_parent" android:background="#FFFF0000" android:gravity="center" android:paddingLeft="20dp" android:textColor="@android:color/white" android:paddingRight="20dp" android:text="删除" /> </LinearLayout> MainActivity
package com.example.listview;import java.util.ArrayList;import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.TextView;
import android.widget.Toast;public class MainActivity extends Activity {private QQListView mListView;private ArrayList<String> mData = new ArrayList<String>() {{for (int i = 0; i < 50; i++) {add("hello world, hello android " + i);}}};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);// 记载布局，只有一个自定义listViewsetContentView(R.layout.activity_main);//获取listview空间mListView = (QQListView) findViewById(R.id.list);//创建并且设置适配器mListView.setAdapter(new MyAdapter());//设置条目监听事件mListView.setOnItemClickListener(new OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> parent, View view,int position, long id) {if (mListView.canClick()) {Toast.makeText(MainActivity.this, mData.get(position),Toast.LENGTH_SHORT).show();}}});}class MyAdapter extends BaseAdapter {@Overridepublic int getCount() {return mData.size();}@Overridepublic Object getItem(int position) {return mData.get(position);}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {if (null == convertView) {convertView = View.inflate(MainActivity.this, R.layout.item,null);}TextView tv = (TextView) convertView.findViewById(R.id.tv);TextView delete = (TextView) convertView.findViewById(R.id.delete);tv.setText(mData.get(position));final int pos = position;delete.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {mData.remove(pos);notifyDataSetChanged();mListView.turnToNormal();}});return convertView;}}
}QQListView
package com.example.listview;import android.content.Context;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.MotionEvent;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.LinearLayout;
import android.widget.ListView;public class QQListView extends ListView {private int mScreenWidth; // 屏幕宽度private int mDownX; // 按下点的x值private int mDownY; // 按下点的y值private int mDeleteBtnWidth;// 删除按钮的宽度private boolean isDeleteShown; // 删除按钮是否正在显示private ViewGroup mPointChild; // 当前处理的itemprivate LinearLayout.LayoutParams mLayoutParams; // 当前处理的item的LayoutParams/*** 构造器*/public QQListView(Context context, AttributeSet attrs) {this(context, attrs, 0);}public QQListView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);// 获取屏幕宽度WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);DisplayMetrics dm = new DisplayMetrics();wm.getDefaultDisplay().getMetrics(dm);mScreenWidth = dm.widthPixels;}@Overridepublic boolean onTouchEvent(MotionEvent ev) {switch (ev.getAction()) {case MotionEvent.ACTION_DOWN:performActionDown(ev);break;case MotionEvent.ACTION_MOVE:return performActionMove(ev);case MotionEvent.ACTION_UP:performActionUp();break;}return super.onTouchEvent(ev);}/*** 处理action_down事件*/private void performActionDown(MotionEvent ev) {// 如果删除按钮处于显示状态，那么就将listview处于正常状态if (isDeleteShown) {turnToNormal();}//获取按下的xy坐标值mDownX = (int) ev.getX();mDownY = (int) ev.getY();// 获取listview中当前点的itemmPointChild = (ViewGroup) getChildAt(pointToPosition(mDownX, mDownY)- getFirstVisiblePosition());Log.e("TAG", ""+pointToPosition(mDownX, mDownY));Log.e("TAG", ""+getFirstVisiblePosition());// 获取每个条目的删除按钮的宽度mDeleteBtnWidth = mPointChild.getChildAt(1).getLayoutParams().width;//获取每个条目的内容区域的布局参数--另外的方式mLayoutParams = (LinearLayout.LayoutParams) mPointChild.getChildAt(0).getLayoutParams();// 为什么要重新设置layout_width 等于屏幕宽度// 因为match_parent时，不管你怎么滑，都不会显示删除按钮// why？ 因为match_parent时，ViewGroup就不去布局剩下的viewmLayoutParams.width = mScreenWidth;mPointChild.getChildAt(0).setLayoutParams(mLayoutParams);}/*** 处理action_move事件*/private boolean performActionMove(MotionEvent ev) {int nowX = (int) ev.getX();int nowY = (int) ev.getY();if (Math.abs(nowX - mDownX) > Math.abs(nowY - mDownY)) {// 如果向左滑动if (nowX < mDownX) {// 计算要偏移的距离int scroll = (nowX - mDownX) / 2;Log.e("TAGG", ""+scroll);Log.e("TAGG", ""+mDeleteBtnWidth);// 如果大于了删除按钮的宽度， 则最大为删除按钮的宽度if (-scroll >= mDeleteBtnWidth) {scroll = -mDeleteBtnWidth;}// 重新设置leftMarginmLayoutParams.leftMargin = scroll;mPointChild.getChildAt(0).setLayoutParams(mLayoutParams);}return true;}return super.onTouchEvent(ev);}/*** 处理action_up事件*/private void performActionUp() {// 偏移量大于button的一半，则显示button// 否则恢复默认if (-mLayoutParams.leftMargin >= mDeleteBtnWidth / 2) {mLayoutParams.leftMargin = -mDeleteBtnWidth;isDeleteShown = true;} else {turnToNormal();}mPointChild.getChildAt(0).setLayoutParams(mLayoutParams);}/*** 变为正常状态*/public void turnToNormal() {mLayoutParams.leftMargin = 0;mPointChild.getChildAt(0).setLayoutParams(mLayoutParams);isDeleteShown = false;}/*** 当前是否可点击* * @return 是否可点击*/public boolean canClick() {return !isDeleteShown;}
}
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