怎么在listview中清除原数据
山上农夫 2018-05-22 09:15:06 之前也看到了用list.clean()方法,但是不知道为什么一直不成功,希望大家帮忙
package com.example.lin.yy1702a_30;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class ListViewDemo extends AppCompatActivity implements View.OnClickListener{
private ListView listView;
private SimpleAdapter simpleAdapter;
public List<Map<String,Object>> list=new ArrayList<Map<String,Object>>();
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_interface);
/*
处理三步走
*/
//第一步得到对象
listView=(ListView)findViewById(R.id.list_item);
//默认数据
ShuJu();
//第二步实例化SimpleAdapter
simpleAdapter=new SimpleAdapter(
this,
list,
R.layout.listview,
new String[]{"class_name","name","text_geren"},
new int[]{R.id.class_name,R.id.name,R.id.text_geren}
);
//第三步设置适配器
listView.setAdapter(simpleAdapter);
}
//数据源--------是我要清除的
protected void ShuJu(){
Map map=new HashMap();
map.put("class_name","计算机1702");
map.put("name","小白");
map.put("text_geren","无");
Map map1=new HashMap();
map1.put("class_name","计算机1702");
map1.put("name","小民");
map1.put("text_geren","无");
Map map2=new HashMap();
map2.put("class_name","计算机1702");
map2.put("name","小天");
map2.put("text_geren","无");
list.add(map);
list.add(map1);
list.add(map2);
}
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.return_button:
finish();
break;
case R.id.add:
final LinearLayout linearLayout=(LinearLayout)getLayoutInflater().inflate(R.layout.load_layout,null);
new AlertDialog.Builder(this)
.setView(linearLayout)
//点击按钮时前面的内容删除,后面的内容添加,怎么做。
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
//是我要添加的
EditText text_class=(EditText)linearLayout.findViewById(R.id.text_class);
EditText text_name=(EditText)linearLayout.findViewById(R.id.text_name);
EditText text_geren=(EditText)linearLayout.findViewById(R.id.text_geren);
TextView class_name=(TextView) findViewById(R.id.class_name);
class_name.setText(text_class.getText().toString());
TextView name=(TextView) findViewById(R.id.name);
name.setText(text_name.getText().toString());
TextView text_geren1=(TextView) findViewById(R.id.text_geren1);
text_geren1.setText(text_geren.getText().toString());
}
}).create().show();
}
}
}