編輯:關於Android編程
最近嘗試做了個listview的多選demo,網上看其他人的例子感覺不是很難,自己動手做了下,各種細節問題,沒那麼簡單啊。既然做了,簡單寫個筆記記錄下。
練手demo,命名筆記亂,不要介意哦。
主界面布局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" android:id="@+id/rootView" 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.example.listchecked.MainActivity" > <ListView android:id="@+id/listView1" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginBottom="50dp" > </ListView> <LinearLayout android:id="@+id/button_group" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignLeft="@+id/listView1" android:layout_alignParentBottom="true" android:orientation="vertical" > <Button android:id="@+id/del" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="刪除" /> </LinearLayout> </RelativeLayout>
列表item的布局
<?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="horizontal" android:descendantFocusability="blocksDescendants" > <!--注意上面這個屬性,很關鍵,不加會導致list無法響應OnItemClickListener中的事件--> <RelativeLayout android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="1" > <CheckBox android:id="@+id/checkBox1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:clickable="false" android:focusable="false" /> <ImageView android:id="@+id/imageView1" android:layout_width="match_parent" android:layout_height="match_parent" android:scaleType="fitCenter" android:src="@drawable/ic_launcher" /> </RelativeLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center" android:orientation="vertical" > <TextView android:id="@+id/title" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Title" android:textSize="20sp" /> <TextView android:id="@+id/teacher" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Teacher" /> <TextView android:id="@+id/time" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Time" /> <TextView android:id="@+id/peopleNum" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="peopleNum" /> </LinearLayout> </LinearLayout>
這個item的布局就被在細節上坑了一次,item中添加button,checkbox,imageButton等時,會導致只響應這些控件的事件,item整體的事件就不會響應了,剛開始沒有加那條屬性,勾選checkbox後,點刪除沒有反應。這問題要發現也有點難度,之前見大神們推薦過分析布局的工具hierarchyviewer,這個工具,個人感覺和前端開發中的F12類似啊,很方便,可以看到每個布局的情況。也是好奇,點開一看,整個item的布局,從父布局,到子布局,只要checkbox可以接受click,其他全部是false,這就是問題所在了,後來百度了一下,即如上結論。
解決辦法就是添加Android:descendantFocusability=”blocksDescendants” 到list的item的布局裡,添加以後,發現checkbox還是可以被單獨點擊,不響應list的點擊選中事件,很是奇怪,看其他人的例子中就沒有這種現象。最後只能設置checkbox不能被點擊 android:clickable=”false” 布局問題解決了,下面是java類的源碼:
首先是bean類,ItemBean.java
package com.example.listchecked; public class ItemBean { private int imgRes; private String title,teacher,time; private int peopleNum,id; private boolean isChecked; private boolean isShow; public boolean isShow() { return isShow; } public void setShow(boolean isShow) { this.isShow = isShow; } public int getId() { return id; } public void setId(int id) { this.id = id; } public boolean isChecked() { return isChecked; } public void setChecked(boolean isChecked) { this.isChecked = isChecked; } public int getImgRes() { return imgRes; } public void setImgRes(int img) { this.imgRes = img; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getTeacher() { return teacher; } public void setTeacher(String teacher) { this.teacher = teacher; } public String getTime() { return time; } public void setTime(String time) { this.time = time; } public int getPeopleNum() { return peopleNum; } public void setPeopleNum(int peopleNum) { this.peopleNum = peopleNum; } }
自定義的Adapter,MyListAdapter.java
package com.example.listchecked; import java.util.List; import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.CheckBox; import android.widget.CompoundButton; import android.widget.CompoundButton.OnCheckedChangeListener; import android.widget.ImageView; import android.widget.TextView; public class MyListAdapter extends BaseAdapter { private LayoutInflater inflater; private List<ItemBean> items; private ItemBean item; private OnShowItemClickListener onShowItemClickListener; public MyListAdapter(List<ItemBean> list,Context context) { items=list; inflater=LayoutInflater.from(context); } @Override public int getCount() { // TODO 自動生成的方法存根 return items.size(); } @Override public Object getItem(int position) { // TODO 自動生成的方法存根 return items.get(position); } @Override public long getItemId(int position) { // TODO 自動生成的方法存根 return items.get(position).getId(); } @Override public View getView(int position, View convertView, ViewGroup parent) { // TODO 自動生成的方法存根 ViewHolder holder;//使用ViewHolder,大神說能提升性能 if(convertView==null) { holder=new ViewHolder(); convertView=inflater.inflate(R.layout.item_view, null); holder.img=(ImageView) convertView.findViewById(R.id.imageView1); holder.cb=(CheckBox) convertView.findViewById(R.id.checkBox1); holder.title=(TextView)convertView.findViewById(R.id.title); holder.teacher=(TextView) convertView.findViewById(R.id.teacher); holder.time=(TextView) convertView.findViewById(R.id.time); holder.poeple=(TextView)convertView.findViewById(R.id.peopleNum); convertView.setTag(holder); }else { holder=(ViewHolder) convertView.getTag(); } item=items.get(position); if(item.isShow()) { holder.cb.setVisibility(View.VISIBLE); } else { holder.cb.setVisibility(View.GONE); } holder.img.setImageResource(item.getImgRes()); holder.title.setText(item.getTitle()); holder.teacher.setText("主講:"+item.getTeacher()); holder.time.setText("課時:"+item.getTime()+"講"); holder.poeple.setText("學習人數:"+item.getPeopleNum()); holder.cb.setOnCheckedChangeListener(new OnCheckedChangeListener() { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { if(isChecked) { item.setChecked(true); } else { item.setChecked(false); } //回調方法,講item加入已選擇的 onShowItemClickListener.onShowItemClick(item); } }); //監聽後設置選擇狀態 holder.cb.setChecked(item.isChecked()); return convertView; } static class ViewHolder { ImageView img; CheckBox cb; TextView title,teacher,time,poeple; } public interface OnShowItemClickListener { public void onShowItemClick(ItemBean bean); } public void setOnShowItemClickListener(OnShowItemClickListener onShowItemClickListener) { this.onShowItemClickListener = onShowItemClickListener; } }
最後是MainActivity.java
package com.example.listchecked; import java.util.ArrayList; import java.util.List; import android.app.Activity; import android.content.Context; import android.os.Bundle; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnClickListener; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.ListView; import android.widget.RelativeLayout; import android.widget.Toast; import com.example.listchecked.MyListAdapter.OnShowItemClickListener; public class MainActivity extends Activity implements OnShowItemClickListener { private ListView listView; private List<ItemBean> dataList,selectedList; private MyListAdapter myAdapter; private RelativeLayout rootView; private LinearLayout menuView; private LinearLayout openView; private static boolean isShow; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); isShow=false; setContentView(R.layout.activity_main); Button delbtn=(Button) findViewById(R.id.del); rootView=(RelativeLayout) findViewById(R.id.rootView); menuView=(LinearLayout) findViewById(R.id.button_group); listView=(ListView) findViewById(R.id.listView1); dataList=new ArrayList<ItemBean>(); selectedList=new ArrayList<ItemBean>(); for(int i=0;i<10;i++) { ItemBean item=new ItemBean(); item.setId(i); item.setImgRes(R.drawable.ic_launcher); item.setTitle("第"+item.getId()+"個"); item.setTeacher("楊老師"); item.setTime("34"); item.setPeopleNum(i+1*100); item.setChecked(false); item.setShow(isShow); dataList.add(item); } myAdapter=new MyListAdapter(dataList, this); myAdapter.setOnShowItemClickListener(MainActivity.this); listView.setAdapter(myAdapter); delbtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO 自動生成的方法存根 showMenu(); isShow=true; selectedList.clear(); for(ItemBean item:dataList) { item.setShow(isShow); } myAdapter.notifyDataSetChanged(); } }); listView.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { // TODO 自動生成的方法存根 if (isShow) { ItemBean item = dataList.get(position); boolean isChecked = item.isChecked(); if (isChecked) { item.setChecked(false); } else { item.setChecked(true); } myAdapter.notifyDataSetChanged(); Log.d("select",selectedList.size()+""); } } }); } //顯示選擇刪除等的菜單 private void showMenu() { RelativeLayout.LayoutParams lp=new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT); lp.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM); LayoutInflater inflater = (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE); openView=(LinearLayout) inflater.inflate(R.layout.delmenu_layout, null); rootView.removeView(menuView); rootView.addView(openView,lp); final Button sBtn=(Button) openView.findViewById(R.id.selectAll); Button dBtn=(Button) openView.findViewById(R.id.del_button); Button cBtn= (Button) openView.findViewById(R.id.cancel_button); sBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO 自動生成的方法存根 if ("全選".equals(sBtn.getText().toString())) { for (ItemBean bean : dataList) { if (!bean.isChecked()) { bean.setChecked(true); if (!selectedList.contains(bean)) { selectedList.add(bean); } } } myAdapter.notifyDataSetChanged(); sBtn.setText("反選"); } else if ("反選".equals(sBtn.getText().toString())) { for (ItemBean bean : dataList) { bean.setChecked(false); if (!selectedList.contains(bean)) { selectedList.remove(bean); } } myAdapter.notifyDataSetChanged(); sBtn.setText("全選"); } } }); dBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO 自動生成的方法存根 if (selectedList!=null && selectedList.size()>0) { dataList.removeAll(selectedList); myAdapter.notifyDataSetChanged(); selectedList.clear(); } else { Toast.makeText(MainActivity.this, "請選擇條目", Toast.LENGTH_SHORT).show(); } } }); cBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO 自動生成的方法存根 if (isShow) { selectedList.clear(); for (ItemBean bean : dataList) { bean.setChecked(false); bean.setShow(false); } myAdapter.notifyDataSetChanged(); isShow = false; restoreView(); } } }); } @Override public void onShowItemClick(ItemBean bean) { // TODO 自動生成的方法存根 if (bean.isChecked() && !selectedList.contains(bean)) { selectedList.add(bean); } else if (!bean.isChecked() && selectedList.contains(bean)) { selectedList.remove(bean); } } private void restoreView() { rootView.addView(menuView); if(openView!=null) { rootView.removeView(openView); openView=null; } } }
最後還有那個小菜單的布局,還是放上吧
<?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="horizontal" > <Button android:id="@+id/selectAll" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:text="全選" /> <Button android:id="@+id/del_button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:text="刪除" /> <Button android:id="@+id/cancel_button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:text="取消" /> </LinearLayout>
全部代碼都放上了,如果不想復制粘貼,GitHub地址:https://github.com/2767321434/ListChecked
以上就是本文的全部內容,希望對大家學習Android軟件編程有所幫助。
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