在实际项目中删除列表中的某一项是非常常见的功能,传统的做法可以使用长按监听器等,而现在流行的做法是左滑弹出删除按钮,微信,QQ等都是这么做的,下面做一个示例,代码如下:
主页面MainActivity:代码比较简单常规
package com.home.testslideview; import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.os.Bundle; import android.widget.ListView; import com.home.textslideview.R; public class MainActivity extends Activity { private ListView listView; private List<NewInfoBean> list = new ArrayList<NewInfoBean>(); // 适配器 private SlideAdapter adapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); initView(); initData(); setAdapter(); } /** * 初始化页面控件 */ private void initView() { listView = (ListView) findViewById(R.id.main_lv); } /** * 初始化数据 */ private void initData() { list.add(new NewInfoBean("这是测试内容1")); list.add(new NewInfoBean("这是测试内容2")); list.add(new NewInfoBean("这是测试内容3")); list.add(new NewInfoBean("这是测试内容4")); list.add(new NewInfoBean("这是测试内容5")); list.add(new NewInfoBean("这是测试内容6")); list.add(new NewInfoBean("这是测试内容7")); list.add(new NewInfoBean("这是测试内容8")); list.add(new NewInfoBean("这是测试内容9")); list.add(new NewInfoBean("这是测试内容10")); } /** * 设置适配器 */ private void setAdapter() { if (adapter == null) { adapter = new SlideAdapter(this, list); listView.setAdapter(adapter); } else { adapter.setList(list); adapter.notifyDataSetChanged(); } } }
实体类NewInfoBean:具体项目中由自己定义:
package com.home.testslideview; public class NewInfoBean { public SlideView slideView; private String content; public SlideView getSlideView() { return slideView; } public void setSlideView(SlideView slideView) { this.slideView = slideView; } public String getContent() { return content; } public void setContent(String content) { this.content = content; } public NewInfoBean() { super(); } public NewInfoBean(String content) { super(); this.content = content; } }
适配器SlideAdapter:也比较简单
package com.home.testslideview; import java.util.List; import android.content.Context; import android.util.SparseArray; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.TextView; import com.home.testslideview.SlideView.OnSlideListener; import com.home.textslideview.R; public class SlideAdapter extends BaseAdapter implements OnSlideListener, OnClickListener { private LayoutInflater inflater; private List<NewInfoBean> list; private Context context; public SlideAdapter(Context context, List<NewInfoBean> list) { if (inflater == null) { inflater = LayoutInflater.from(context); } this.list = list; this.context = context; } @Override public int getCount() { return list.size(); } @Override public Object getItem(int position) { return list.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup arg2) { SlideView slideView = (SlideView) convertView; NewInfoBean bean = list.get(position); if (slideView == null) { slideView = new SlideView(context); slideView.setOnSlideListener(this); } // 设置内容 TextView contentText = getAdapterView(slideView, R.id.slideview_tv_content, position); contentText.setText(bean.getContent()); // 删除按钮 TextView delText = getAdapterView(slideView, R.id.slideview_tv_del, position); delText.setOnClickListener(this); bean.slideView = slideView; bean.slideView.shrink(); return slideView; } @SuppressWarnings("unchecked") public <T extends View> T getAdapterView(View convertView, int id, Object tag) { SparseArray<View> viewHolder = null; try { if (convertView.getTag(R.id.view_holder) instanceof SparseArray<?>) { viewHolder = (SparseArray<View>) convertView .getTag(R.id.view_holder); } } catch (ClassCastException e) { } if (viewHolder == null) { viewHolder = new SparseArray<View>(); convertView.setTag(R.id.view_holder, viewHolder); convertView.setTag(R.id.order_id, tag); } View childView = viewHolder.get(id); if (childView == null) { childView = convertView.findViewById(id); childView.setTag(tag); viewHolder.put(id, childView); } return (T) childView; } public List<NewInfoBean> getList() { return list; } public void setList(List<NewInfoBean> list) { this.list = list; } @Override public void onSlide(View view, int status) { } @Override public void onClick(View v) { switch (v.getId()) { case R.id.slideview_tv_del: int position = (Integer) v.getTag(); list.remove(position); notifyDataSetChanged(); break; default: break; } } }
比较关键的两个类:
自定义的ListView:SlideListView
package com.home.testslideview; import android.content.Context; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; import android.widget.ListView; public class SlideListView extends ListView { private SlideView itemView; public SlideListView(Context context) { super(context); } public SlideListView(Context context, AttributeSet attrs) { super(context, attrs); } public void shrinkListItem(int position) { View item = getChildAt(position); if (item != null) { try { ((SlideView) item).shrink(); } catch (ClassCastException e) { e.printStackTrace(); } } } @Override public boolean onTouchEvent(MotionEvent event) { switch (event.getAction()) { case MotionEvent.ACTION_DOWN: { int x = (int) event.getX(); int y = (int) event.getY(); int position = pointToPosition(x, y); if (position != INVALID_POSITION) { NewInfoBean data = (NewInfoBean) getItemAtPosition(position); itemView = data.slideView; } } default: break; } if (itemView != null) { itemView.onRequireTouchEvent(event); } return super.onTouchEvent(event); } }
自定义的ListView中的每一行控件:SlideView(借鉴网上的一个示例):
package com.home.testslideview; import android.content.Context; import android.util.AttributeSet; import android.util.Log; import android.util.TypedValue; import android.view.LayoutInflater; import android.view.MotionEvent; import android.view.View; import android.widget.LinearLayout; import android.widget.Scroller; import com.home.textslideview.R; public class SlideView extends LinearLayout { private static final String TAG = SlideView.class.getSimpleName(); private Context mContext; private Scroller mScroller; private OnSlideListener mOnSlideListener; private int mHolderWidth = 80; private int mLastX = 0; private int mLastY = 0; private static final int TAN = 2; private LayoutInflater inflater; public interface OnSlideListener { public static final int SLIDE_STATUS_OFF = 0; public static final int SLIDE_STATUS_START_SCROLL = 1; public static final int SLIDE_STATUS_ON = 2; /** * @param view * current SlideView * @param status * SLIDE_STATUS_ON or SLIDE_STATUS_OFF */ public void onSlide(View view, int status); } public SlideView(Context context) { super(context); initView(); } public SlideView(Context context, AttributeSet attrs) { super(context, attrs); initView(); } private void initView() { mContext = getContext(); if (inflater == null) { inflater = LayoutInflater.from(mContext); } mScroller = new Scroller(mContext); setOrientation(LinearLayout.HORIZONTAL); View.inflate(mContext, R.layout.slide_view_merge, this); mHolderWidth = Math.round(TypedValue.applyDimension( TypedValue.COMPLEX_UNIT_DIP, mHolderWidth, getResources() .getDisplayMetrics())); } public void setOnSlideListener(OnSlideListener onSlideListener) { mOnSlideListener = onSlideListener; } public void shrink() { if (getScrollX() != 0) { this.smoothScrollTo(0, 0); } } public void onRequireTouchEvent(MotionEvent event) { int x = (int) event.getX(); int y = (int) event.getY(); int scrollX = getScrollX(); Log.d(TAG, "x=" + x + " y=" + y); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: { if (!mScroller.isFinished()) { mScroller.abortAnimation(); } if (mOnSlideListener != null) { mOnSlideListener.onSlide(this, OnSlideListener.SLIDE_STATUS_START_SCROLL); } break; } case MotionEvent.ACTION_MOVE: { int deltaX = x - mLastX; int deltaY = y - mLastY; if (Math.abs(deltaX) < Math.abs(deltaY) * TAN) { break; } int newScrollX = scrollX - deltaX; if (deltaX != 0) { if (newScrollX < 0) { newScrollX = 0; } else if (newScrollX > mHolderWidth) { newScrollX = mHolderWidth; } this.scrollTo(newScrollX, 0); } break; } case MotionEvent.ACTION_UP: { int newScrollX = 0; if (scrollX - mHolderWidth * 0.75 > 0) { newScrollX = mHolderWidth; } this.smoothScrollTo(newScrollX, 0); if (mOnSlideListener != null) { mOnSlideListener.onSlide(this, newScrollX == 0 ? OnSlideListener.SLIDE_STATUS_OFF : OnSlideListener.SLIDE_STATUS_ON); } break; } default: break; } mLastX = x; mLastY = y; } private void smoothScrollTo(int destX, int destY) { // 缓慢滚动到指定位置 int scrollX = getScrollX(); int delta = destX - scrollX; mScroller.startScroll(scrollX, 0, delta, 0, Math.abs(delta) * 3); invalidate(); } @Override public void computeScroll() { if (mScroller.computeScrollOffset()) { scrollTo(mScroller.getCurrX(), mScroller.getCurrY()); postInvalidate(); } } }
main.xml:
<?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" > <com.home.testslideview.SlideListView android:id="@+id/main_lv" android:layout_width="match_parent" android:layout_height="match_parent" android:cacheColorHint="#00000000" android:fadingEdge="none" android:listSelector="#00000000" android:scrollbars="none" /> </LinearLayout>
slide_view_merge.xml:
<?xml version="1.0" encoding="utf-8"?> <merge xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal" > <LinearLayout android:id="@+id/slideview_layout_content" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center_vertical" android:gravity="center_vertical" android:orientation="horizontal" > <TextView android:id="@+id/slideview_tv_content" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="内容部分"/> </LinearLayout> <LinearLayout android:id="@+id/view_layout_del" android:layout_width="80dp" android:layout_height="match_parent" android:layout_gravity="center_vertical" android:layout_toRightOf="@id/slideview_layout_content" android:clickable="true" android:gravity="center_vertical" android:orientation="horizontal" > <TextView android:id="@+id/slideview_tv_del" android:layout_width="80dp" android:layout_height="match_parent" android:layout_marginBottom="2dp" android:gravity="center" android:padding="15dp" android:text="删除"/> </LinearLayout> </merge>
源码下载:高仿微信左滑删除效果
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