学步园

     在项目中有时候要用到ListView动态添加一些Item，今天研究了一下，一贯还是使用BaseAdapter

创建一个AddNumberBaseAdpater类用来适配ListView

import java.util.ArrayList;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.ImageButton;

import com.example.mobilephone.R;

public class AddNumberBaseAdpater extends BaseAdapter {

 private LayoutInflater mInflater;
 private ArrayList<String> text;

 public AddNumberBaseAdpater(Context context) {
  text = new ArrayList<String>();
  text.add("第一项");// 默认只加载一个Item
  this.mInflater = LayoutInflater.from(context);
 }

 public int getCount() {
  // TODO Auto-generated method stub
  return text.size();
 }

 public Object getItem(int position) {
  // TODO Auto-generated method stub
  return text.get(position);
 }

 public long getItemId(int position) {
  // TODO Auto-generated method stub
  return position;
 }

 public View getView(final int position, View convertView, ViewGroup parent) {
  // TODO Auto-generated method stub
  ViewHolder holder = new ViewHolder();
  if (convertView == null) {
   convertView = mInflater.inflate(R.layout.addnumber, null);
   holder.btnOpen = (ImageButton) convertView
     .findViewById(R.id.ibtnAddNumber);
   holder.editText = (EditText) convertView
     .findViewById(R.id.editNumber);
   convertView.setTag(holder);
  } else {
   holder = (ViewHolder) convertView.getTag();
  }
  switch (position) {// 不要以为XML文件中是2个按钮，其实只有一个
  case 0:
   holder.btnOpen.setBackgroundResource(R.drawable.addnumber);// 第一项按钮则显示加号图片
   break;

  default:
   holder.btnOpen.setBackgroundResource(R.drawable.deletenumber);// 超过了一项则显示减号图片，可以删除
   break;
  }
  holder.btnOpen.setOnClickListener(new View.OnClickListener() {// 添加按钮

     public void onClick(View v) {
      if (position == 0) {
       text.add("xxx");// 添加一项控件

      } else if (position > 0) {// 始终留一项不能删除

       text.remove(text.size() - 1);// 删除按钮
      }
      notifyDataSetChanged();
     }
    });

  return convertView;
 }

 public final class ViewHolder {
  public EditText editText;
  public ImageButton btnOpen;

 }
}


 

主MainActivity

import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;

import com.example.mobilephone.adpater.AddNumberBaseAdpater;

public class MainActivity extends Activity {

	private ListView myList; // ListView控件 

	private AddNumberBaseAdpater addNumberBaseAdpater;
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.moble_input); 
		addNumberBaseAdpater=new AddNumberBaseAdpater(getApplicationContext());
		myList = (ListView) findViewById(R.id.listview1);
		myList.setAdapter(addNumberBaseAdpater);

	}
}

  自定义XML文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/relativeNumber"
    android:layout_width="500px"
    android:layout_height="100px"
    android:layout_below="@+id/relativeLayout1"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="20dp" >

    <EditText
        android:id="@+id/editNumber"
        android:layout_width="300px"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:gravity="center_vertical"
        android:layout_centerHorizontal="true"
        android:layout_marginLeft="16dp"
        android:background="@drawable/number_input"
        android:ems="10" />

    <ImageButton
        android:id="@+id/ibtnAddNumber"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:focusable="true"         
        android:layout_toRightOf="@+id/editNumber"
        android:background="@drawable/addnumber" /> 
</RelativeLayout>

主XML文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FFFFFF" 
    android:orientation="vertical" >
    <ListView
        android:id="@+id/listview1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:cacheColorHint="#00000000"
        android:layout_centerHorizontal="true"
        android:divider="#FFFFFF"
        android:dividerHeight="0px"
        android:fadingEdge="none"
        android:listSelector="#00000000"  > 
    </ListView>

     <TextView
         android:id="@+id/textVie"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_centerHorizontal="true"
         android:layout_below="@+id/listview1"
         android:text="@string/input"
         android:textSize="18dp" />
    
</RelativeLayout>

最后运行效果如下，第一次显示

点击加号按钮后运行效果如下：

点击减号删除