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CursorAdapter

继承e68a84e8a2ad62616964757a686964616f31333361303030于BaseAdapter是个虚类,它为cursor和ListView提供了连接的桥梁。

public abstract class

CursorAdapter

extends BaseAdapter

直接子类只有ResourceCursorAdapter

Class Overview

Adapter that exposes data from a Cursor to a ListView widget.

The Cursor must include a column named "_id" or this class will not work.

注意cursor的必须要有个命名为"_id"的列。比如Contacts._ID就为"_id"

必须实现以下函数：

abstract View newView(Context context, Cursor cursor, ViewGroup parent)

Makes a new view to hold the data pointed to by cursor.

abstract void bindView(View view, Context context, Cursor cursor)

Bind an existing view to the data pointed to by cursor

注意：

newView该函数第一次回调用后，如果数据增加后也会再调用，但是重绘是不会调用的。

数据增加后,回调用该函数来生成与新增数据相对应的view。

bindView函数第一次回调用后，如果数据更新也会再调用，但重绘会再次调用的。

【总的来说应该是在调用bindView如果发现view为空会先调用newView来生成view】

i

[java]

view plaincopy

mport java.util.List;

import android.app.Activity;

import android.app.ListActivity;

import android.os.Bundle;

import android.os.Handler;

import android.content.Context;

import android.content.ContentValues;

import android.database.Cursor;

import android.view.LayoutInflater;

import android.view.View;

import android.widget.ListView;

import android.view.ViewGroup;

import android.widget.ArrayAdapter;

import android.widget.CursorAdapter;

import android.widget.TextView;

import android.provider.ContactsContract.Contacts;

import android.provider.ContactsContract.RawContacts;

import android.view.View.OnClickListener;

import android.widget.Button;

public class HelloCursor extends ListActivity {

private static String[] PROJECTION = new String[] { Contacts._ID,

Contacts.DISPLAY_NAME };

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

Cursor c = getContentResolver().query(Contacts.CONTENT_URI, PROJECTION,

null, null, Contacts.DISPLAY_NAME + " COLLATE NOCASE");

startManagingCursor(c);

MyCursorAdapter adapter = new MyCursorAdapter(this, R.layout.list_row,

c);

this.setListAdapter(adapter);

Button button = (Button)findViewById(R.id.Button01);

OnClickListener listener=new OnClickListener(){

@Override

public void onClick(View v) {

doAction();

}

};

button.setOnClickListener(listener);

mHandler = new Handler();

}

private String[] mStrings = { "hubin", "hudashi", "robin" };

int cnt = 0;

private Handler mHandler;

class AddContactThread implements Runnable {

public void run() {

int nStringLength = mStrings.length;

int randomNumber = 0;

ContentValues newValues = new ContentValues();

String tempString = null;

randomNumber = (int) (Math.random() % 10);

for (int i = 0; i < nStringLength; i++) {

tempString = mStrings + cnt + randomNumber;

newValues.put(Contacts.DISPLAY_NAME, tempString);

getContentResolver().insert(RawContacts.CONTENT_URI, newValues);

newValues.clear();

}

cnt++;

}

}

AddContactThread addContact=new AddContactThread();

void doAction()

{

mHandler.post(addContact);

}

}

class MyCursorAdapter extends CursorAdapter {

Context context=null;

int viewResId;

public MyCursorAdapter(Context context, int resource, Cursor cursor) {

super(context,cursor);

viewResId=resource;

}

public View newView(Context context, Cursor cursor, ViewGroup parent) {

TextView view =null;

LayoutInflater vi = null;

vi = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

view =(TextView)vi.inflate(viewResId, parent, false);

//v =(TextView)vi.inflate(textViewResourceId,null);

Log.i("hubin","newView"+view);

return view;

}

@Override

public void bindView(View view, Context context, Cursor cursor) {

Log.i("hubin","bind"+view);

TextView nameView = (TextView) view;

// Set the name

nameView.setText(cursor

.getString(cursor.getColumnIndex("DISPLAY_NAME")));

}

}

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