今天跟大家简单的说说,我们在开发中有时候会遇到listview中有checkbox,由于我们重用了convertView,但是一些错误问题!这种解决思路,是我的之前一个朋友跟我说的,他以前工作中,遇到这个问题,他的一种解决思路,现在分享给大家
效果图:
接下来简单的说说listview一些优化:
1、布局文件的android:layout_width,android:layout_height 设置要非“wrap_content”,如果这里不这么设置的话,getView将会被重复执行3~4次
2、给convertView设置Tag,为了是减少findViewById
布局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">
<ListView
android:id="@+id/listview"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</RelativeLayout>
<?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" >
<TextView
android:id="@+id/tv_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<EditText
android:id="@+id/et_print"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
/>
<CheckBox
android:id="@+id/cbo_test"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<Button
android:id="@+id/btn_commit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="提交"
/>
</LinearLayout>
实体的代码:
package com.example.bamboo_listview_viewholder;
/**
* 测试的实体类
* @author bamboo
*
*/
public class TestBean {
private String name;
/** 是否选中 为了防止错位*/
private boolean isChecked;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public boolean isChecked() {
return isChecked;
}
public void setChecked(boolean isChecked) {
this.isChecked = isChecked;
}
}
adapter.java的源代码:
package com.example.bamboo_listview_viewholder;
import java.util.ArrayList;
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.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class MyAdapter extends BaseAdapter {
private List<TestBean> mList;
private Context mContext;
public MyAdapter(Context context) {
this.mContext = context;
this.mList = new ArrayList<TestBean>();
}
/**
* 添加数据源
*
* @param list
*/
public void add(List<TestBean> list) {
this.mList.addAll(list);
this.notifyDataSetChanged();
}
@Override
public int getCount() {
return mList.size();
}
@Override
public Object getItem(int position) {
return mList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder mHolder = null;
if (convertView == null) {
mHolder = new ViewHolder();
convertView = LayoutInflater.from(mContext).inflate(
R.layout.item_listview, null);
mHolder.tv_name = (TextView) convertView.findViewById(R.id.tv_name);
mHolder.et_print = (EditText) convertView
.findViewById(R.id.et_print);
mHolder.cbo_test = (CheckBox) convertView
.findViewById(R.id.cbo_test);
mHolder.btn_commit = (Button) convertView
.findViewById(R.id.btn_commit);
mHolder.cbo_test
.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
/** 这里选中后,将是数据源中的属性也做改变 */
int position = Integer.valueOf(buttonView.getTag()
.toString());
mList.get(position).setChecked(isChecked);
}
});
mHolder.btn_commit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
/** 获取button的父布局 */
<span style="color:#ff0000;">View pView = (View) v.getParent();
EditText et = (EditText) pView.findViewById(R.id.et_print);
Toast.makeText(mContext, et.getText().toString(), 0).show();</span>
}
});
convertView.setTag(mHolder);
} else {
mHolder = (ViewHolder) convertView.getTag();
}
TestBean bean = mList.get(position);
mHolder.tv_name.setText(bean.getName());
mHolder.cbo_test.setTag(position);
/** 设置是否选中 */
mHolder.cbo_test.setChecked(bean.isChecked());
return convertView;
}
class ViewHolder {
private TextView tv_name;
private EditText et_print;
private CheckBox cbo_test;
private Button btn_commit;
}
}
MainActivity.java的源代码:
package com.example.bamboo_listview_viewholder;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.ListView;
public class MainActivity extends Activity {
private ListView listview;
/** 适配器*/
private MyAdapter mAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listview=(ListView) this.findViewById(R.id.listview);
mAdapter=new MyAdapter(this);
getData();
listview.setAdapter(mAdapter);
}
/** 添加数据源*/
public void getData(){
List<TestBean> list=new ArrayList<TestBean>();
for(int i=0 ; i<30; i++){
TestBean t=new TestBean();
t.setName("bamboo_"+i);
t.setChecked(false);
list.add(t);
}
mAdapter.add(list);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
这里面还有一个问题,昨天我朋友问我,如何点击里面的button,而获取edittext的输入内容,我想了想用上面红色的代码实现的,不知道这种方式实现好不好?
大家如果还有别的思路可以提供!
源代码下载: