Android將圖像保存到新文件夾

Question

我試圖將之前拍攝的圖像保存到不同的文件夾（該文件夾已存在）。我的清單是最新的，我需要的權限，我知道我需要沿該線使用的東西：

MediaStore.Images.Media.insertImage(getContentResolver(), yourBitmap, yourTitle , yourDescription); 

以下是我的代碼。我做錯了什麼，它不會保存？謝謝！

save.setOnClickListener（新View.OnClickListener（）{

@Override 
public void onClick(View v) { 
// TODO Auto-generated method stub 

int id = viewIt.getId(); 

String root = Environment.getExternalStorageDirectory().toString(); 
String myDir = new String(root + "/New Directory/Folder 1/"); 
String description = ""; 
String filestring = arrPath[id];   
try { 
    MediaStore.Images.Media.insertImage(getContentResolver(), myDir, filestring, description); 
    } catch (FileNotFoundException e) { 
    // TODO Auto-generated catch block 
    e.printStackTrace(); 
    } 
    sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, 
    Uri.parse("file://" + Environment.getExternalStorageDirectory()))); 

    Toast.makeText(getApplicationContext(), "Save Successful", Toast.LENGTH_SHORT).show();   


    } 
}); 

下面是我的logcat錯誤：

04-20 17:38:03.763: E/AndroidRuntime(1003): FATAL EXCEPTION: main 
04-20 17:38:03.763: E/AndroidRuntime(1003): java.lang.NullPointerException 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at android.provider.MediaStore$Images$Media.insertImage(MediaStore.java:551) 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at com.test.Import$ImageAdapter$2$4$1.onClick(Import.java:339) 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at android.view.View.performClick(View.java:2485) 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at android.view.View$PerformClick.run(View.java:9080) 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at android.os.Handler.handleCallback(Handler.java:587) 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at android.os.Handler.dispatchMessage(Handler.java:92) 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at android.os.Looper.loop(Looper.java:123) 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at android.app.ActivityThread.main(ActivityThread.java:3683) 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at java.lang.reflect.Method.invokeNative(Native Method) 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at java.lang.reflect.Method.invoke(Method.java:507) 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
04-20 17:38:03.763: E/AndroidRuntime(1003):  at dalvik.system.NativeStart.main(Native Method) 

Answer 1

我想通了！我決定走一條不同的路線，只是重命名文件。我意識到我不想要多個相同的圖像（試圖節省SD卡空間），所以我做了這個，而不是：

int id = viewIt.getId(); 

File sdcard = Environment.getExternalStorageDirectory(); 
File sdddcard = new File(sdcard + "/New Directory/Folder 1/"); 

File from = new File(arrPath[id]); 


Random generator = new Random(); 
int n = 10000; 
n = generator.nextInt(n); 
String filename = "ImageImport-"+ n +".jpg"; 

File to = new File(sdddcard,filename); 

from.renameTo(to); 

Answer 2

1）空間的文件夾名稱可能有一些問題，所以一定要確保你檢查文件夾是否存在，否則創建它。

File file = new File(myDirPath); 
if(!file.exists()) { 
    if(!file.mkdirs()){ 
    Log.e("TAG", "Error: You can't create folder"); 
    } 
} 

2）有可能是一個錯誤，但你沒有看到它，因爲你捕獲異常但不打印它。

嘗試更換此

e.printStackTrace(); 

與

Log.e("TAG", "Error: "+ e.toString());