protected static void excuteSuCMD() { 
   Process process = null; 
   OutputStream out = null; 
   InputStream in = null; 
   String currentTempFilePath = "/sdcard/QQ.apk"; 
   try { 
   // 请求root 
   process = Runtime.getRuntime().exec("su"); 
   out = process.getOutputStream(); 
   // 调用安装 
   out.write(("pm install -r " + currentTempFilePath + "\n").getBytes()); 
   in = process.getInputStream(); 
   int len = 0; 
   byte[] bs = new byte[256]; 
   while (-1 != (len = in.read(bs))) { 
   String state = new String(bs, 0, len); 
   if (state.equals("Success\n")) { 
    //安装成功后的操作 
     } 
    } 
   } catch (IOException e) { 
    e.printStackTrace(); 
   } catch (Exception e) { 
    e.printStackTrace(); 
   } finally { 
    try { 
     if (out != null) { 
      out.flush(); 
      out.close(); 
     } 
     if (in != null) { 
      in.close(); 
     } 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
   } 
  } 

public static void openFile() { 
  // 核心是下面几句代码 
  if (!isHasfile()) { 
   downLoadFile(url); 
  } 
  Intent intent = new Intent(); 
  intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
  intent.setAction(android.content.Intent.ACTION_VIEW); 
  intent.setDataAndType( 
    Uri.fromFile(new File("/sdcard/update/updata.apk")), 
    "application/vnd.android.package-archive"); 
  mContext.startActivity(intent); 
 }