1.Loader特性:(1).对于每个Activity或者Fragment都可用(2).提供异步加载数据(3).监视数据资源,当内容改变时重新更新(4).当配置改变时,自动重新连接最新的cursor,故不需要重新查询数据2.Loader相关类接口(1).LoaderManager对于每个activity或者fragment只存在一个与之相关的LoaderManager对象,该LoaderManag
public class MyTest extends AndroidTestCase { public MyTest() { // TODO Auto-generated constructor stub } public void insert()&n
一、在AndroidManifest.xml文件中添加 <provider android:name=".StudentProvider" &n
在我们使用真机进行Android应用调试时,无法获得调试信息,错误提示如下:Unable to open log device ‘/dev/log/main’: No such file or directory这是因为我们的手机没有开起log记录,下面以华为c8812为例开启手机的log功能 方法:1、在拨号界面输入:*#*#2846579#*#* 进入测试菜单界面&nbs
传递消息的集中方式:一:Message message = Message.obtain(); message.obj = data; message.what = IS_FINISHED; handle.sendMessage(message);二:Message message = Message.obtain(handle); message.obj = data; message.
在UI线程中创建子线程——》在子线程中获取网络图片--》在线程中通过Message 传递二进制图片给Handler,--》Handler在handleMessage()中处理消息package com.example.android_handler_message; import java.io.IOException; import org.apache.http.HttpResponse; i
import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import org.apache.http.HttpResponse; import org.apache.http.client.Ht
When an asynchronous task is executed, the task goes through 4 steps:onPreExecute(), invoked on the UI thread before the task is executed. This step is normally used to setup the task, f
package com.example.android_db.dao; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import android.content.ContentValues; import android.content.Cont
定义接口package com.example.android_db.service; import java.util.List; import java.util.Map; public interface PersonService { public boolean addPerson(Object[] params);
一、实现一个类,继承SQLiteOpenHelper类,并实现构造函数,onCreate() onUpgrade()import android.content.Context; import android.database.DatabaseErrorHandler; import android.database.sqlite.SQLiteDatabase; import andr
import java.util.HashMap; import java.util.Map; import android.content.Context; import android.content.SharedPreferences; public class MySharedpreference { private Context context; public MySh
import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.UnsupportedEncodingException; import java.net.HttpURLConnectio
import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL; import org.apach
public static String createJsonString(String key, Object value) { JSONObject jsonObject = new JSONObject(); jsonObject.put(key, value); return jsonObject.toString(); }
import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import android.R.integer; import android.content.Context; import android.os.Environment; public class
一:显示Intent intent = new Intent(Intent.ACTION_DIAL); startActivity(intent);二、一般操作,运用URI(Android查看URI的方案,询问哪个活动处理VIEW)Intent intent = new Intent(Intent.ACTION_VIEW); intent.setData(Uri.parse("http://www
在第一个activity中使用startActivityForResult(intent, state_tag);启动第二个activity,在第二个activity中调用 setResult(,)在第一个activity中重载onActivityResult()第一个Activity:public class MainActivity extends Activity { private
通过在content(如activity)中调用startService(Intent )启动service,service只有在调用stopSelf(),或者另外component调用stopService()时才会停止。service启动时会自动调用onStartCommand(Intent intent, int flags, int startId)Service类:This is the
Dialog类public class TestDialog extends DialogFragment implements View.OnClickListener{ TextView textView; EditText editText; Button button_save; Button button_dismiss; Button butto
Canvas canvas = holder.lockCanvas(); canvas.drawRGB(255, 0, 0); holder.unlockCanvasAndPost(canvas);第一行,锁定Surface用于渲染并返回一个可用的Canvas第二行,解锁Surface并确保通过Canvas进行绘制的内容可显示到屏幕上例子:import android.os.Bundle; imp
设置全屏: activity中requestWindowFeature(Window.FEATURE_NO_TITLE); getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); 加
为上下文菜单注册Viewprotected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);
菜单的添加public boolean onCreateOptionsMenu(Menu menu) { super.onCreateOptionsMenu(menu); menu.add(0, 1, 0, "xia"); menu.add(0, 2, 1, "gengj"); menu.add(0, 3, 2, "jia"); me
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