看看我的代码怎么出问题了?有关listview,adapter,ContentObserver,DatabaseOpenHelper的。
2017-01-02 07:44
435 查看
主布局:
注册文件:
主活动代码:
[code]package com.lhj.asus.store;
import android.app.Activity;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import com.lhj.asus.store.db.Message;
import com.lhj.asus.store.db.Msg;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.Inflater;
/**
* Created by asus on 2016/5/13.
* 点击按钮向数据库里插入数据,并且在前台的listview中显示
* 每次打开的时候数据都可以直接查询显示
* ContentProvider,内容提供者,可以操作自身的数据库进行增删该查
*
*/
public class MessageObserverActivity extends AppCompatActivity {
private EditText et;
private ListView lv;
private List<String> list = new ArrayList<String>();
private ContentResolver resolver;
private String uri = "content://com.lhj.asus.store/message";
private MyAdapter adapter;
private Handler handler = new Handler(new Handler.Callback() {
@Override
public boolean handleMessage(android.os.Message msg) {
if (msg.what == 200){
list.add(0,msg.obj.toString());
adapter.notifyDataSetChanged();
}
return true;
}
});
private MsgObserver observer;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_message_observer);
et = (EditText)findViewById(R.id.et);
observer = new MsgObserver(handler,this);
lv = (ListView)findViewById(R.id.lv);
resolver = getContentResolver();
//注册观察者
resolver.registerContentObserver(Uri.parse(uri),true,observer);
//查询数据库获取内容
initDatas();
//适配器初始化
adapter = new MyAdapter();
lv.setAdapter(adapter);
}
@Override
protected void onDestroy() {
super.onDestroy();
resolver.unregisterContentObserver(observer);
}
private void initDatas() {
Cursor cursor = resolver.query(Uri.parse(uri), null, null, null, "_id desc");
if (cursor!=null){
while (cursor.moveToNext()){
//取出数据
String msg = cursor.getString(cursor.getColumnIndex("msg"));
list.add(msg);
}
//关闭cursor
cursor.close();
}
}
//点击按钮的方法
public void click(View v){
ContentValues values = new ContentValues();
values.put("msg",et.getText().toString());
resolver.insert(Uri.parse(uri),values);
}
class MyAdapter extends BaseAdapter{
@Override
public int getCount() {
return list.size();
}
@Override
public String getItem(int position) {
return list.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/msg_tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="message"
android:padding="10dp" />
</LinearLayout>
注册文件:
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.lhj.asus.store"> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission> <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"></uses-permission> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission> <uses-permission android:name="android.permission.READ_CONTACTS"></uses-permission> <uses-permission android:name="android.permission.CALL_PHONE"></uses-permission> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name="com.lhj.asus.store.MainActivity"> <!--<intent-filter>--> <!--<action android:name="android.intent.action.MAIN"/>--> <!--<category android:name="android.intent.category.LAUNCHER"/>--> <!--</intent-filter>--> </activity> <activity android:name="com.lhj.asus.store.MessageObserverActivity"> <intent-filter> <action android:name="android.intent.action.MAIN"/> <category android:name="android.intent.category.LAUNCHER"/> </intent-filter> </activity> <provider android:authorities="com.lhj.asus.store" android:name="com.lhj.asus.store.MsgProvider"></provider> </application> </manifest>
主活动代码:
[code]package com.lhj.asus.store;
import android.app.Activity;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import com.lhj.asus.store.db.Message;
import com.lhj.asus.store.db.Msg;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.Inflater;
/**
* Created by asus on 2016/5/13.
* 点击按钮向数据库里插入数据,并且在前台的listview中显示
* 每次打开的时候数据都可以直接查询显示
* ContentProvider,内容提供者,可以操作自身的数据库进行增删该查
*
*/
public class MessageObserverActivity extends AppCompatActivity {
private EditText et;
private ListView lv;
private List<String> list = new ArrayList<String>();
private ContentResolver resolver;
private String uri = "content://com.lhj.asus.store/message";
private MyAdapter adapter;
private Handler handler = new Handler(new Handler.Callback() {
@Override
public boolean handleMessage(android.os.Message msg) {
if (msg.what == 200){
list.add(0,msg.obj.toString());
adapter.notifyDataSetChanged();
}
return true;
}
});
private MsgObserver observer;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_message_observer);
et = (EditText)findViewById(R.id.et);
observer = new MsgObserver(handler,this);
lv = (ListView)findViewById(R.id.lv);
resolver = getContentResolver();
//注册观察者
resolver.registerContentObserver(Uri.parse(uri),true,observer);
//查询数据库获取内容
initDatas();
//适配器初始化
adapter = new MyAdapter();
lv.setAdapter(adapter);
}
@Override
protected void onDestroy() {
super.onDestroy();
resolver.unregisterContentObserver(observer);
}
private void initDatas() {
Cursor cursor = resolver.query(Uri.parse(uri), null, null, null, "_id desc");
if (cursor!=null){
while (cursor.moveToNext()){
//取出数据
String msg = cursor.getString(cursor.getColumnIndex("msg"));
list.add(msg);
}
//关闭cursor
cursor.close();
}
}
//点击按钮的方法
public void click(View v){
ContentValues values = new ContentValues();
values.put("msg",et.getText().toString());
resolver.insert(Uri.parse(uri),values);
}
class MyAdapter extends BaseAdapter{
@Override
public int getCount() {
return list.size();
}
@Override
public String getItem(int position) {
return list.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
相关文章推荐
- 解决java.lang.IllegalStateException: The content of the adapter has changed but ListView...的问题
- 在线程汇总更新UI的注意问题The content of the adapter has changed but ListView did not receive a notification. Ma
- android SQLite (Cursor SQLiteDatabase SQLiteOpenHelper ContentValues ContentProvider) 总结
- 问题解决:The content of the adapter has changed but ListView did not receive a notification
- java.lang.IllegalStateException:The content of the adapter has changed but ListView did not receiv问题
- 35、拦截黑名单、ViewHolder、对listView的优化、SQLiteOpenHelper、数据库的增删改查 listView&BaseAdapter、按钮变更(button_select)
- 解决问题The content of the adapter has changed but ListView did not receive a notification.
- 关于Adapter的The content of the adapter has changed but ListView did not receive a notification.问题分析
- android4————SQLiteOpenHelper SQLiteDatabase ContentProvider三者的关系
- java.lang.IllegalStateException: The content of the adapter has changed but ListView...的问题
- 解决java.lang.IllegalStateException: The content of the adapter has changed but ListView...的问题
- 求人看看这个代码,有关DLL中使用回调函数的问题:回调不能返回正确值
- 解决ListView的The content of the adapter has changed but ListView did not receive a notification崩溃问题
- 解决java.lang.IllegalStateException: The content of the adapter has changed but ListView...的问题
- 【转】解决java.lang.IllegalStateException: The content of the adapter has changed but ListView...的问题
- 解决The content of the adapter has changed but ListView did not receive a notification的问题
- Android中ListView的addFooterView不显示的有关问题和adapter
- ListView数据源不同步问题The content of the adapter has changed but ListView did not receive a notification.
- listview刷新点击,出现The content of the adapter has changed but ListView did not receive a notification问题
- Android问题3-ListView Adapter(The content of the adapter has changed but ListView did not receive a n)