Android 常用代码集合

这篇文章主要记录一些我常用的一些代码段，方便以后查阅，不断更新中

1 调用浏览器 载入某网址

Uri uri = Uri.parse("http://www.baidu.com");        
Intent it = new Intent(Intent.ACTION_VIEW, uri);        
startActivity(it);

2 Broadcast接收系统广播的intent 监控应用程序包的安装 删除

public class getBroadcast extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
               
                  if(Intent.ACTION_PACKAGE_ADDED.equals(intent.getAction())){
                    Toast.makeText(context, "有应用被添加", Toast.LENGTH_LONG).show();
            }
                else  if(Intent.ACTION_PACKAGE_REMOVED.equals(intent.getAction())){
                    Toast.makeText(context, "有应用被删除", Toast.LENGTH_LONG).show();
            }
             
                else  if(Intent.ACTION_PACKAGE_REPLACED.equals(intent.getAction())){
                    Toast.makeText(context, "有应用被替换", Toast.LENGTH_LONG).show();
            }
                  
                else  if(Intent.ACTION_CAMERA_BUTTON.equals(intent.getAction())){
                    Toast.makeText(context, "按键", Toast.LENGTH_LONG).show();
            }
            
        }
       
}

需要声明的权限如下AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="zy.Broadcast"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".Broadcast"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
      <receiver android:name="getBroadcast" android:enabled="true" >
         <intent-filter>
	         <action android:name="android.intent.action.PACKAGE_ADDED"></action>
	         <!-- <action android:name="android.intent.action.PACKAGE_CHANGED"></action>-->
	         <action android:name="android.intent.action.PACKAGE_REMOVED"></action>
	         <action android:name="android.intent.action.PACKAGE_REPLACED"></action>
	         <!-- <action android:name="android.intent.action.PACKAGE_RESTARTED"></action>-->
	       <!--    <action android:name="android.intent.action.PACKAGE_INSTALL"></action>-->
	           <action android:name="android.intent.action.CAMERA_BUTTON"></action>
	           <data android:scheme="package"></data>
              </intent-filter>
</receiver>
    </application>
    <uses-sdk android:minSdkVersion="3" />
    
</manifest> 

3 使用Toast输出一个字符串

public void DisplayToast(String str)
	    {
	  Toast.makeText(this,str,Toast.LENGTH_SHORT).show();
	    } 

4 把一个字符串写进文件

public void writefile(String str,String path )
	    {
	    	File file;
	    	FileOutputStream out;
	    	 try {
	             //创建文件
	    		 file = new File(path);
	             file.createNewFile();
	             
	             //打开文件file的OutputStream
	             out = new FileOutputStream(file);
	             String infoToWrite = str;
	             //将字符串转换成byte数组写入文件
	             out.write(infoToWrite.getBytes());
	             //关闭文件file的OutputStream
	             out.close();
	             
	             
	             
	         } catch (IOException e) {
	             //将出错信息打印到Logcat
	       	  DisplayToast(e.toString());
	             
	         }
	    }

5 把文件内容读出到一个字符串

public String getinfo(String path)
	    {
	    	File file;
	    	String str=""; 
	    	FileInputStream in;
	     try{
	    	//打开文件file的InputStream
	    	 file = new File(path);
	         in = new FileInputStream(file);
	         //将文件内容全部读入到byte数组
	         int length = (int)file.length();
	         byte[] temp = new byte[length];
	         in.read(temp, 0, length);
	         //将byte数组用UTF-8编码并存入display字符串中
	         str =  EncodingUtils.getString(temp,TEXT_ENCODING);
	         //关闭文件file的InputStream
	         
	         in.close();
	     }
	     catch (IOException e) {
	         
	   	  DisplayToast(e.toString());
	         
	     }
	     return str;
	    }

6 调用Android installer 安装和卸载程序

 Intent intent = new Intent(Intent.ACTION_VIEW); 
        intent.setDataAndType(Uri.fromFile(new File("/sdcard/WorldCupTimer.apk")), "application/vnd.android.package-archive"); 
        startActivity(intent); //安装 程序
        
        Uri packageURI = Uri.parse("package:zy.dnh");     
        Intent uninstallIntent = new Intent(Intent.ACTION_DELETE, packageURI);     
        startActivity(uninstallIntent);//正常卸载程序

7 结束某个进程

activityManager.restartPackage(packageName);

8 设置默认来电铃声

public void setMyRingtone()
    {
   File k = new File("/sdcard/Shall We Talk.mp3"); // 设置歌曲路径
    ContentValues values = new ContentValues();
    values.put(MediaStore.MediaColumns.DATA, k.getAbsolutePath());
    values.put(MediaStore.MediaColumns.TITLE, "Shall We Talk");
    values.put(MediaStore.MediaColumns.SIZE, 8474325);
    values.put(MediaStore.MediaColumns.MIME_TYPE, "audio/mp3");
    values.put(MediaStore.Audio.Media.ARTIST, "Madonna");
    values.put(MediaStore.Audio.Media.DURATION, 230);
    values.put(MediaStore.Audio.Media.IS_RINGTONE, true);
    values.put(MediaStore.Audio.Media.IS_NOTIFICATION, false);
    values.put(MediaStore.Audio.Media.IS_ALARM, false);
    values.put(MediaStore.Audio.Media.IS_MUSIC, false);
    // Insert it into the database
    Uri uri = MediaStore.Audio.Media.getContentUriForPath(k.getAbsolutePath());
    Uri newUri = this.getContentResolver().insert(uri, values);
    RingtoneManager.setActualDefaultRingtoneUri(this, RingtoneManager.TYPE_RINGTONE, newUri);
    ;}

需要的权限

<uses-permission android:name="android.permission.WRITE_SETTINGS"></uses-permission>

模拟HOME按键

Intent i=new Intent(Intent.ACTION_MAIN);
i.addCategory(Intent.CATEGORY_HOME);
i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);

9 打开某一个联系人

Intent intent=new Intent();
String data = "content://contacts/people/1";
Uri  uri = Uri.parse(data);			 intent.setAction(Intent.ACTION_VIEW);
intent.setData(uri);
startActivity(intent);