參考網(wǎng)上大神的例子,自己照著大意寫了一遍(留著參考,方便日后使用)
1、新建MyListView 繼承自ListView 重寫方法
代碼如下:
package com.deletetest;import android.content.Context;import android.util.AttributeSet;import android.util.DisplayMetrics;import android.view.MotionEvent;import android.view.ViewGroup;import android.view.WindowManager;import android.widget.LinearLayout;import android.widget.ListView;/** * Created by Administrator on 2016/12/9. */public class MyListView extends ListView { PRivate int mScreenWidth; // 屏幕寬度 private int mDownX; // 按下點(diǎn)的x值 private int mDownY; // 按下點(diǎn)的y值 private int mDeleteBtnWidth;// 刪除按鈕的寬度 private boolean isDeleteShown; // 刪除按鈕是否正在顯示 private ViewGroup mPointChild; // 當(dāng)前處理的item private LinearLayout.LayoutParams mLayoutParams;// 當(dāng)前處理的item的LayoutParams public MyListView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public MyListView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); // 獲取屏幕寬度 WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); DisplayMetrics dm = new DisplayMetrics(); wm.getDefaultDisplay().getMetrics(dm); mScreenWidth = dm.widthPixels; } @Override public 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); } // 處理action_down事件 private void performActionDown(MotionEvent ev) { if(isDeleteShown) { turnToNormal(); } mDownX = (int) ev.getX(); mDownY = (int) ev.getY(); // 獲取當(dāng)前點(diǎn)的item mPointChild = (ViewGroup) getChildAt(pointToPosition(mDownX, mDownY) - getFirstVisiblePosition()); // 獲取刪除按鈕的寬度 mDeleteBtnWidth = mPointChild.getChildAt(1).getLayoutParams().width; mLayoutParams = (LinearLayout.LayoutParams) mPointChild.getChildAt(0) .getLayoutParams(); // 為什么要重新設(shè)置layout_width 等于屏幕寬度 // 因?yàn)閙atch_parent時(shí),不管你怎么滑,都不會(huì)顯示刪除按鈕 // why? 因?yàn)閙atch_parent時(shí),ViewGroup就不去布局剩下的view mLayoutParams.width = mScreenWidth; mPointChild.getChildAt(0).setLayoutParams(mLayoutParams); } // 處理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)) { // 如果向左滑動(dòng) if(nowX < mDownX) { // 計(jì)算要偏移的距離 int scroll = (nowX - mDownX) / 3; // 如果大于了刪除按鈕的寬度, 則最大為刪除按鈕的寬度 if(-scroll >= mDeleteBtnWidth) { scroll = -mDeleteBtnWidth; } // 重新設(shè)置leftMargin mLayoutParams.leftMargin = scroll; mPointChild.getChildAt(0).setLayoutParams(mLayoutParams); } return true; } return super.onTouchEvent(ev); } // 處理action_up事件 private void performActionUp() { // 偏移量大于button的一半,則顯示button // 否則恢復(fù)默認(rèn) if(-mLayoutParams.leftMargin >= mDeleteBtnWidth / 3) { mLayoutParams.leftMargin = -mDeleteBtnWidth; isDeleteShown = true; }else { turnToNormal(); } mPointChild.getChildAt(0).setLayoutParams(mLayoutParams); } /** * 變?yōu)檎顟B(tài) */ public void turnToNormal() { mLayoutParams.leftMargin = 0; mPointChild.getChildAt(0).setLayoutParams(mLayoutParams); isDeleteShown = false; } /** * 當(dāng)前是否可點(diǎn)擊 * @return 是否可點(diǎn)擊 */ public boolean canClick() { return !isDeleteShown; }}2、activity側(cè)代碼:
package com.deletetest;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.view.ViewGroup;import android.widget.AdapterView;import android.widget.BaseAdapter;import android.widget.TextView;import android.widget.Toast;import java.util.ArrayList;public class MainActivity extends AppCompatActivity { private MyListView mListView; private ArrayList<String> mData = new ArrayList<String>() { { for(int i=0;i<50;i++) { add("十言" + i); } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mListView = (MyListView) findViewById(R.id.list); mListView.setAdapter(new MyAdapter()); mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public 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 { @Override public int getCount() { return mData.size(); } @Override public Object getItem(int position) { return mData.get(position); } @Override public long getItemId(int position) { return position; } @Override public 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 View.OnClickListener() { @Override public void onClick(View v) { mData.remove(pos); notifyDataSetChanged(); mListView.turnToNormal(); Toast.makeText(MainActivity.this,"已刪除",Toast.LENGTH_SHORT).show(); } }); return convertView; } }}3、activity側(cè)布局
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.deletetest.MainActivity"> <com.loupai.deletetest.MyListView 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" android:scrollbars="none"/></RelativeLayout>4、item布局如下
<?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="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="100dp" android:layout_height="match_parent" android:background="#FFFF0000" android:gravity="center" android:textColor="@android:color/white" android:paddingRight="20dp" android:text="刪除" /></LinearLayout>
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