強制寫入SD卡時關閉（安卓）

我有一個應用程序，將數據備份到SD卡。當插入SD卡時，它可以很好地工作，並將備份數據。當SD卡不存在時，我編程它創建一個警告，告訴用戶未找到SD卡。強制寫入SD卡時關閉（安卓）

我遇到的問題是，如果有人試圖導出數據的第一次沒有SD卡存在，它會強制關閉。但是，如果他們先備份一組數據，然後在嘗試備份更多數據時再沒有SD卡，則會以我想要的方式顯示警報消息。

有人請幫忙！繼承人我的代碼（從教程修改）：

InputStream myInput; 

try { 

    myInput = new FileInputStream("/data/data/com.android.footprint/databases/MY_DATABASE"); 

    File directory = new File("/sdcard/Footprint"); 

    if (!directory.exists()) 
    { 
     directory.mkdirs(); 
    } 


    OutputStream myOutput = new FileOutputStream(directory.getPath()+ "/MY_DATABASE.backup"); 


    byte[] buffer = new byte[1024]; 
    int length; 
    while ((length = myInput.read(buffer))>0) 
    { 
     myOutput.write(buffer, 0, length); 
    } 

    myOutput.flush(); 

    myOutput.close(); 

    myInput.close(); 

    alertDialog2 = new AlertDialog.Builder(
      settings.this).create(); 
    alertDialog2.setTitle("Export Complete"); 
    alertDialog2.setMessage("Data Backup successful"); 
    alertDialog2.setButton("Ok", new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialog, int which) { 
      alertDialog2.dismiss(); 
     } 
    }); 
    alertDialog2.show(); 

} catch (FileNotFoundException e) { 
    alertDialog2.dismiss(); 
    alertDialog3 = new AlertDialog.Builder(
      settings.this).create(); 
    alertDialog3.setIcon(R.drawable.delete); 
    alertDialog3.setTitle("Export Failed"); 
    alertDialog3.setMessage("Make sure SD card is inserted and unmounted"); 
    alertDialog3.setButton("Ok", new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialog, int which) { 
      alertDialog3.dismiss(); 
     } 
    }); 
    alertDialog3.show(); 
} catch (IOException e) { 
    alertDialog2.dismiss(); 
    alertDialog3 = new AlertDialog.Builder(
      settings.this).create(); 
    alertDialog3.setIcon(R.drawable.delete); 
    alertDialog3.setTitle("Export Failed"); 
    alertDialog3.setMessage("Make sure SD card is inserted and unmounted"); 
    alertDialog3.setButton("Ok", new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialog, int which) { 
      alertDialog3.dismiss(); 
     } 
    }); 
    alertDialog3.show(); 
} catch (Exception e) { 
    alertDialog2.dismiss(); 
    alertDialog3 = new AlertDialog.Builder(
      settings.this).create(); 
    alertDialog3.setIcon(R.drawable.delete); 
    alertDialog3.setTitle("Export Failed"); 
    alertDialog3.setMessage("Make sure SD card is inserted and unmounted"); 
    alertDialog3.setButton("Ok", new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialog, int which) { 
      alertDialog3.dismiss(); 
     } 
    }); 
    alertDialog3.show(); 
}

來源

2012-02-21 725623452362

使用此代碼檢查SD卡：

public static boolean isSdPresent() { 
    return android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED); 
}

我發現這對這個link。希望這有助於..

來源

2012-02-21 20:34:53 Deepak

不知道這是否是你的問題，但它是一個好主意，審查你檢查的方式，如果SD卡存在。以下是我在我的最新的應用程序的一個處理它：

String state = Environment.getExternalStorageState(); 

    if (Environment.MEDIA_MOUNTED.equals(state)) { 
     // Everything is fine, write away ! 
    } else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) { 
     // Card is in read mode, cannot write 
     Log.e("FileManager", "SD Card is in READ ONLY mode, impossible to write files."); 
    } else { 
     // Impossible to access SD Card 
     Log.e("FileManager", "Having trouble with SD card, can't write nor read from it."); 
    }

另外，我建議你從Environement類中，像這樣的靜態方法得到你的路徑：

File root = Environment.getExternalStorageDirectory(); 
    File directory = new File(root + "/Footprint");

希望這幫助你解決你的問題！

來源

2012-02-21 20:37:14

強制寫入SD卡時關閉（安卓）

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