android listview左滑删除

之前，自己使用listview一直是长按删除，不过发现qq的消息和ios的都是侧滑删除，觉得效果很好，于是自己就想做一个侧滑删除。在网上找了些资料，有很多不是我理想的侧滑删除，最后还是找到了一个不错的，现在记录一下。

首先是自定义一个listview，这个里面需要重写onInterceptTouchEvent和onTouchEvent两个代码，一个是对滑动进行拦截，如果删除按钮已经显示，点击的不是删除的item,则把按钮隐藏。另一个是对item滑动的事件进行处理。滑动时item移动，显示删除按钮。

package com.zviewtech.videonetclient.mydeleteemo;


import android.content.Context;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.TypedValue;
import android.view.MotionEvent;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.LinearLayout;
import android.widget.ListView;

/**
 * Created by JunkChen on 2016/3/29 0029.
 */
public class SideslipListView extends ListView {
    private static final String TAG = "SideslipListView";

    private int mScreenWidth;//屏幕的宽度
    private boolean isDeleteShow;//删除组件是否显示
    private ViewGroup mPointChild;//手指按下位置的item组件
    private int mDeleteWidth;//删除组件的宽度
    private LinearLayout.LayoutParams mItemLayoutParams;//手指按下时所在的item的布局参数
    private int mDownX;//手指初次按下的X坐标
    private int mDownY;//手指初次按下的Y坐标

    private int mPointPosition;//手指按下位置所在的item位置
    private boolean isAllowItemClick;//是否允许item点击

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

    public SideslipListView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context);
    }

    public SideslipListView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context);
    }

    private void init(Context context) {
        // 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;
        Log.i(TAG, "***********mScreenWidth: " + mScreenWidth);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {//事件拦截
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN: {
                isAllowItemClick = true;

                //侧滑删除
                mDownX = (int) ev.getX();
                mDownY = (int) ev.getY();
                mPointPosition = pointToPosition(mDownX, mDownY);
                Log.i(TAG, "*******pointToPosition(mDownX, mDownY): " + mPointPosition);
                if (mPointPosition != -1) {
                    if (isDeleteShow) {
                        ViewGroup tmpViewGroup = (ViewGroup) getChildAt(mPointPosition - getFirstVisiblePosition());
                        if (!mPointChild.equals(tmpViewGroup)) {
                            turnNormal();
                        }
                    }
                    //获取当前的item
                    mPointChild = (ViewGroup) getChildAt(mPointPosition - getFirstVisiblePosition());

                    mDeleteWidth = mPointChild.getChildAt(1).getLayoutParams().width;
                    mItemLayoutParams = (LinearLayout.LayoutParams) mPointChild.getChildAt(0).getLayoutParams();

                    Log.i(TAG, "*********mItemLayoutParams.height: " + mItemLayoutParams.height +
                            ", mDeleteWidth: " + mDeleteWidth);
                    mItemLayoutParams.width = mScreenWidth;
                    mPointChild.getChildAt(0).setLayoutParams(mItemLayoutParams);
                }
                break;
            }
            case MotionEvent.ACTION_MOVE: {
                int nowX = (int) ev.getX();
                int nowY = (int) ev.getY();
                int diffX = nowX - mDownX;
                Log.i(TAG, "******dp2px(4): " + dp2px(8) + ", dp2px(8): " + dp2px(8) +
                        ", density: " + getContext().getResources().getDisplayMetrics().density);
                if (Math.abs(diffX) > dp2px(4) || Math.abs(nowY - mDownY) > dp2px(4)) {
                    return true;//避免子布局中有点击的控件时滑动无效
                }
                break;
            }
        }
        return super.onInterceptTouchEvent(ev);
    }

    public float dp2px(int dp) {
        return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp,
                getContext().getResources().getDisplayMetrics());
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {//事件响应
        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN:
                performActionDown(ev);
                break;
            case MotionEvent.ACTION_MOVE:
                performActionMove(ev);
                break;
            case MotionEvent.ACTION_UP:
                performActionUp(ev);
                break;
        }
        return super.onTouchEvent(ev);
    }

    private void performActionDown(MotionEvent ev) {
        mDownX = (int) ev.getX();
        mDownY = (int) ev.getY();
        if (isDeleteShow) {
            ViewGroup tmpViewGroup = (ViewGroup) getChildAt(pointToPosition(mDownX, mDownY) - getFirstVisiblePosition());
            Log.i(TAG, "*********mPointChild.equals(tmpViewGroup): " + mPointChild.equals(tmpViewGroup));
            if (!mPointChild.equals(tmpViewGroup)) {
                turnNormal();
            }
        }
        //获取当前的item
        mPointChild = (ViewGroup) getChildAt(pointToPosition(mDownX, mDownY) - getFirstVisiblePosition());

        mDeleteWidth = mPointChild.getChildAt(1).getLayoutParams().width;//获取删除组件的宽度
        Log.i(TAG, "**********pointToPosition(x,y): " + pointToPosition(mDownX, mDownY)
                + ", getFirstVisiblePosition() = " + getFirstVisiblePosition()
                + ", mDeleteWidth = " + mDeleteWidth);
        mItemLayoutParams = (LinearLayout.LayoutParams) mPointChild.getChildAt(0).getLayoutParams();

        mItemLayoutParams.width = mScreenWidth;
        mPointChild.getChildAt(0).setLayoutParams(mItemLayoutParams);
    }

    private boolean performActionMove(MotionEvent ev) {
        int nowX = (int) ev.getX();
        int nowY = (int) ev.getY();
        int diffX = nowX - mDownX;
        if (Math.abs(diffX) > Math.abs(nowY - mDownY) && Math.abs(nowY - mDownY) < 20) {
            if (!isDeleteShow && nowX < mDownX) {//删除按钮未显示时向左滑
                if (-diffX >= mDeleteWidth) {//如果滑动距离大于删除组件的宽度时进行偏移的最大处理
                    diffX = -mDeleteWidth;
                }
                mItemLayoutParams.leftMargin = diffX;
                mPointChild.getChildAt(0).setLayoutParams(mItemLayoutParams);
                isAllowItemClick = false;
            } else if (isDeleteShow && nowX > mDownX) {//删除按钮显示时向右滑
                if (diffX >= mDeleteWidth) {
                    diffX = mDeleteWidth;
                }
                mItemLayoutParams.leftMargin = diffX - mDeleteWidth;
                mPointChild.getChildAt(0).setLayoutParams(mItemLayoutParams);
                isAllowItemClick = false;
            }
            return true;
        }
        return super.onTouchEvent(ev);
    }

    private void performActionUp(MotionEvent ev) {
        //如果向左滑出超过隐藏的二分之一就全部显示
        if (-mItemLayoutParams.leftMargin >= mDeleteWidth / 2) {
            mItemLayoutParams.leftMargin = -mDeleteWidth;
            isDeleteShow = true;
            mPointChild.getChildAt(0).setLayoutParams(mItemLayoutParams);
        } else {
            turnNormal();
        }
    }

    /**
     * 转换为正常隐藏情况
     */
    public void turnNormal() {
        mItemLayoutParams.leftMargin = 0;
        mPointChild.getChildAt(0).setLayoutParams(mItemLayoutParams);
        isDeleteShow = false;
    }

    /**
     * 是否允许Item点击
     *
     * @return
     */
    public boolean isAllowItemClick() {
        return isAllowItemClick;
    }
}

这个listview主要是设置leftMargin这个左偏移来保证按钮的显示和隐藏的。activity里调用的代码也很简单

package com.zviewtech.videonetclient.mydeleteemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
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 static final String TAG = "MainActivity";
    private SideslipListView mSideslipListView;

    /**
     * 初始化数据
     */
    private ArrayList<String> mDataList = new ArrayList<String>() {
        {
            for (int i = 0; i < 50; i++) {
                add("ListView item  " + i);
            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mSideslipListView = (SideslipListView) findViewById(R.id.sideslipListView);
        mSideslipListView.setAdapter(new CustomAdapter());//设置适配器
        //设置item点击事件
        mSideslipListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView parent, View view, int position, long id) {
                if (mSideslipListView.isAllowItemClick()) {
                    Log.i(TAG, mDataList.get(position) + "被点击了");
                    Toast.makeText(MainActivity.this, mDataList.get(position) + "被点击了",
                            Toast.LENGTH_SHORT).show();
                }
            }
        });
        //设置item长按事件
        mSideslipListView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView parent, View view, int position, long id) {
                if (mSideslipListView.isAllowItemClick()) {
                    Log.i(TAG, mDataList.get(position) + "被长按了");
                    Toast.makeText(MainActivity.this, mDataList.get(position) + "被长按了",
                            Toast.LENGTH_SHORT).show();
                    return true;//返回true表示本次事件被消耗了，若返回
                }
                return false;
            }
        });
    }

    /**
     * 自定义ListView适配器
     */
    class CustomAdapter extends BaseAdapter {
        @Override
        public int getCount() {
            return mDataList.size();
        }

        @Override
        public Object getItem(int position) {
            return mDataList.get(position);
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ViewHolder viewHolder;
            if (null == convertView) {
                convertView = View.inflate(MainActivity.this, R.layout.item, null);
                viewHolder = new ViewHolder();
                viewHolder.textView = (TextView) convertView.findViewById(R.id.textView);
                viewHolder.txtv_delete = (TextView) convertView.findViewById(R.id.txtv_delete);
                convertView.setTag(viewHolder);
            } else {
                viewHolder = (ViewHolder) convertView.getTag();
            }
            viewHolder.textView.setText(mDataList.get(position));
            final int pos = position;
            viewHolder.txtv_delete.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Toast.makeText(MainActivity.this, mDataList.get(pos) + "被删除了",
                            Toast.LENGTH_SHORT).show();
                    mDataList.remove(pos);
                    notifyDataSetChanged();
                    mSideslipListView.turnNormal();
                }
            });
            return convertView;
        }
    }

    class ViewHolder {
        public TextView textView;
        public TextView txtv_delete;
    }
}

其实和普通的listview是一致的，只是在点击时判断滑动变量，如果为true，则不响应点击事件。如果为false，则响应点击事件。

listview的item的布居我要显示出来，因为这和自定义的listview的代码相关，必须是这样的，如果修改，则mDeleteWidth = mPointChild.getChildAt(1).getLayoutParams().width；这里也必须做相应的修改，getChild（）的参数和删除按钮的位置一致

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="wrap_content" >

    <LinearLayout android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="wrap_content" android:padding="8dp">

        <TextView
            android:id="@+id/textView"
            android:layout_width="match_parent"
            android:layout_height="48dp"
            android:textSize="18sp"
            android:text="text">

        </TextView>



    </LinearLayout>
    <!--必须指定宽度-->
    <TextView android:id="@+id/txtv_delete" android:layout_width="96dp"
        android:layout_height="match_parent"
        android:textSize="18sp" android:text="删除" android:textColor="#eeeeee" android:gravity="center" android:background="#e53935">
    </TextView>
</LinearLayout>

listview的滑动删除就完成了。

就这么简单。