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本篇文章给大家分享的是有关怎么在Android中利用ListView实现一个侧滑删除功能,小编觉得挺实用的,因此分享给大家学习,希望大家阅读完这篇文章后可以有所收获,话不多说,跟着小编一起来看看吧。
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需求:
1、listView可以侧滑item,展示删除按钮,点击删除按钮,删除当前的item
2、在删除按钮展示时,点击隐藏删除按钮,不响应item的点击事件
3、在删除按钮隐藏时,点击item响应点击事件
根据以上需求在网络上查找响应的例子,也有仿QQ侧滑代码,但不能满足2和3的要求,因此修改了一把,代码如下,共大家拍砖
第一步:重写ListView
public class SwipeListView extends ListView { private final static String TAG = "SwipeListView"; 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 = false; // 删除按钮是否正在显示 private boolean isOnClick = false; private ViewGroup mPointChild; // 当前处理的item private LinearLayout.LayoutParams mLayoutParams; // 当前处理的item的LayoutParams public SwipeListView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public SwipeListView(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; } @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: return performActionUp(ev); // break; } return super.onTouchEvent(ev); } // 处理action_down事件 private void performActionDown(MotionEvent ev) { // Log.e(TAG,"performActionDown===="+isDeleteShown); if (isDeleteShown) { turnToNormal(); } isOnClick = true; mDownX = (int) ev.getX(); mDownY = (int) ev.getY(); // 获取当前点的item int downPosition = pointToPosition(mDownX, mDownY); int firstPosition= getFirstVisiblePosition(); Log.e(TAG,"performActionDown====downPosition:"+downPosition+"==firstPosition"+firstPosition); if(downPosition < 0) return; mPointChild = (ViewGroup) getChildAt(downPosition-firstPosition); // 获取删除按钮的宽度 mDeleteBtnWidth = mPointChild.getChildAt(1).getLayoutParams().width; 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view mLayoutParams.width = mScreenWidth; mPointChild.getChildAt(0).setLayoutParams(mLayoutParams); } // 处理action_move事件 private boolean performActionMove(MotionEvent ev) { // Log.e(TAG, "performActionMove====" + isDeleteShown); int nowX = (int) ev.getX(); int nowY = (int) ev.getY(); isOnClick = false; 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; // 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leftMargin mLayoutParams.leftMargin = scroll; mPointChild.getChildAt(0).setLayoutParams(mLayoutParams); } return true; } return super.onTouchEvent(ev); } // 处理action_up事件 private boolean performActionUp(MotionEvent ev) { boolean falg = false; if(isOnClick && !isDeleteShown) { falg = true; } // 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(); isDeleteShown = false; } mPointChild.getChildAt(0).setLayoutParams(mLayoutParams); // Log.e(TAG, "performActionUp====" + isDeleteShown); if(falg) { return super.onTouchEvent(ev); } return true; } /** * 变为正常状态 */ public void turnToNormal() { mLayoutParams.leftMargin = 0; mPointChild.getChildAt(0).setLayoutParams(mLayoutParams); } /** * 当前是否可点击 * * @return 是否可点击 */ public boolean canClick() { return !isDeleteShown; } }
第二步:适配器
class SwipeListAdapter 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) { ViewHolder holder = null; if (null == convertView) { holder = new ViewHolder(); convertView = View.inflate(TestListViewActivity.this, R.layout.item_swipe_list, null); holder.tv = (LinearLayout) convertView.findViewById(R.id.tv); holder.tvName = (TextView) convertView.findViewById(R.id.tv_name); holder.delete = (TextView) convertView.findViewById(R.id.delete); convertView.setTag(holder); } else { holder = (ViewHolder) convertView.getTag(); } holder.tvName.setText(mData.get(position)); final int pos = position; holder.delete.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { mData.remove(pos); notifyDataSetChanged(); mListView.turnToNormal(); } }); return convertView; } } static class ViewHolder { LinearLayout tv; TextView tvName; TextView delete; }
第三步:写一个TestListViewActivity
private SwipeListView mListView; private ArrayListmData = new ArrayList () { { for (int i = 0; i < 20; i++) { add("hello world, hello android " + i); } } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_test_list_view); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); fab.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) .setAction("Action", null).show(); } }); mListView = (SwipeListView) findViewById(R.id.list); mListView.setAdapter(new SwipeListAdapter()); // mListView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() { // @Override // public boolean onItemLongClick(AdapterView> parent, View view, int position, long id) { // Toast.makeText(TestListViewActivity.this, mData.get(position) + "被点击了", // Toast.LENGTH_SHORT).show(); // return false; // } // }); mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView> parent, View view, int position, long id) { Log.e("SwipeListView", "setOnItemClickListener====" + mListView.canClick()); // Toast.makeText(TestListViewActivity.this, mData.get(position) + "被点击了", // Toast.LENGTH_SHORT).show(); } }); }
第四步:布局文件
第五步:item的布局文件
重点注意:
int downPosition = pointToPosition(mDownX, mDownY);
downPosition 在使用过程中得到-1,导致后面方法调用异常!
以上就是怎么在Android中利用ListView实现一个侧滑删除功能,小编相信有部分知识点可能是我们日常工作会见到或用到的。希望你能通过这篇文章学到更多知识。更多详情敬请关注创新互联行业资讯频道。
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