圖像顯示null的選定路徑

Question

我已經提到這個sample。

單擊上傳按鈕，一次上傳多個文件到服務器。

但我得到selectedpath1和selectedpath2空指針異常。我不知道如何解決這一個。任何人都可以幫助我這個。謝謝。

logcat的：

02-12 02:12:15.001: E/selectedImageUri(11964): content://com.android.providers.media.documents/document/image%3A388 
02-12 02:12:15.006: E/selectedPath1(11964): null 
02-12 02:12:26.949: E/selectedImageUri(11964): content://com.android.providers.media.documents/document/image%3A388 
02-12 02:12:26.956: E/selectedPath2(11964): null 

MainActivity.java：

public class MainActivity extends Activity { 

    private static final int SELECT_FILE1 = 1; 
    private static final int SELECT_FILE2 = 2; 
    String selectedPath1; 
    String selectedPath2; 
    TextView tv, res; 
    ProgressDialog progressDialog; 
    Button b1, b2, b3; 
    HttpEntity resEntity; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     tv = (TextView) findViewById(R.id.tv); 
     res = (TextView) findViewById(R.id.res); 
     tv.setText(tv.getText() + selectedPath1 + "," + selectedPath2); 
     b1 = (Button) findViewById(R.id.Button01); 
     b2 = (Button) findViewById(R.id.Button02); 
     b3 = (Button) findViewById(R.id.upload); 

     b1.setOnClickListener(new OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       openGallery(SELECT_FILE1); 
      } 
     }); 

     b2.setOnClickListener(new OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       openGallery(SELECT_FILE2); 
      } 
     }); 

     b3.setOnClickListener(new OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       if (!(selectedPath1.equals("")) 
         && !(selectedPath2.equals(""))) { 
        progressDialog = ProgressDialog.show(MainActivity.this, 
          "", "Uploading files to server.....", false); 
        Thread thread = new Thread(new Runnable() { 
         public void run() { 
          doFileUpload(); 
          runOnUiThread(new Runnable() { 
           public void run() { 
            if (progressDialog.isShowing()) 
             progressDialog.dismiss(); 
           } 
          }); 
         } 
        }); 
        thread.start(); 
       } else { 
        Toast.makeText(getApplicationContext(), 
          "Please select two files to upload.", 
          Toast.LENGTH_SHORT).show(); 
       } 
      } 
     }); 

    } 

    public void openGallery(int req_code) { 

     Intent intent = new Intent(); 
     intent.setType("image/*"); 
     intent.setAction(Intent.ACTION_GET_CONTENT); 
     startActivityForResult(
       Intent.createChooser(intent, "Select file to upload "), 
       req_code); 
    } 

    public void onActivityResult(int requestCode, int resultCode, Intent data) { 

     if (resultCode == RESULT_OK) { 
      Uri selectedImageUri = data.getData(); 

      Log.e("selectedImageUri", ""+selectedImageUri); 

      if (requestCode == SELECT_FILE1) { 
       selectedPath1 = getPath(selectedImageUri); -->path is Null 

       Log.e("selectedPath1", ""+selectedPath1); 

      } 

      if (requestCode == SELECT_FILE2) { 
       selectedPath2 = getPath(selectedImageUri); 

       Log.e("selectedPath2", ""+selectedPath2); 
      } 
      tv.setText("Selected File paths : " + selectedPath1 + "," 
        + selectedPath2); 
     } 
    } 

    public String getPath(Uri uri) { 
     String[] projection = { MediaStore.Images.Media.DATA }; 
     Cursor cursor = managedQuery(uri, projection, null, null, null); 
     int column_index = cursor 
       .getColumnIndexOrThrow(MediaStore.Images.Media.DATA); 
     cursor.moveToFirst(); 
     return cursor.getString(column_index); 
    } 

    private void doFileUpload() { 

     File file1 = new File(selectedPath1); 
     File file2 = new File(selectedPath2); 
     String urlString = "http://10.0.2.2/upload_test/upload_media_test.php"; 
     try { 
      HttpClient client = new DefaultHttpClient(); 
      HttpPost post = new HttpPost(urlString); 
      FileBody bin1 = new FileBody(file1); 
      FileBody bin2 = new FileBody(file2); 
      MultipartEntity reqEntity = new MultipartEntity(); 
      reqEntity.addPart("uploadedfile1", bin1); 
      reqEntity.addPart("uploadedfile2", bin2); 
      reqEntity.addPart("user", new StringBody("User")); 
      post.setEntity(reqEntity); 
      HttpResponse response = client.execute(post); 
      resEntity = response.getEntity(); 
      final String response_str = EntityUtils.toString(resEntity); 
      if (resEntity != null) { 
       Log.i("RESPONSE", response_str); 
       runOnUiThread(new Runnable() { 
        public void run() { 
         try { 
          res.setTextColor(Color.GREEN); 
          res.setText("n Response from server : n " 
            + response_str); 
          Toast.makeText(
            getApplicationContext(), 
            "Upload Complete. Check the server uploads directory.", 
            Toast.LENGTH_LONG).show(); 
         } catch (Exception e) { 
          e.printStackTrace(); 
         } 
        } 
       }); 
      } 
     } catch (Exception ex) { 
      Log.e("Debug", "error: " + ex.getMessage(), ex); 
     } 
    } 
} 

activity_main.xml中：

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical" > 

    <TextView 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:text="Multiple File Upload from CoderzHeaven" /> 

    <Button 
     android:id="@+id/Button01" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="Get First File" > 
    </Button> 

    <Button 
     android:id="@+id/Button02" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="Get Second File" > 
    </Button> 

    <Button 
     android:id="@+id/upload" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="Start Upload" > 
    </Button> 

    <TextView 
     android:id="@+id/tv" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:text="Selected File path : " /> 

    <TextView 
     android:id="@+id/res" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:text="" /> 

</LinearLayout> 

Answer 1

內容ù返回的RI可能會有所不同，具體取決於所做的選擇。特別是介紹存儲訪問框架（SAF）的Kitkat（API級別19），您可以在選擇照片的同時查看所有文檔存儲提供商。 這個問題（和它的修復）已在以下StackOverflow的線程得到解決：

Android Gallery on KitKat returns different Uri for Intent.ACTION_GET_CONTENT

retrieve absolute path when select image from gallery kitkat android

或者乾脆你可以做到以下幾點： -

@Override 
public void onActivityResult(int requestCode, int resultCode, Intent data) { 
    super.onActivityResult(requestCode, resultCode, data); 
    if (resultCode == Activity.RESULT_OK) { 
     InputStream inputStream = context.getContentResolver().openInputStream(data.getData()); 
     //Now you can do whatever you want with your inpustream, save it as file, upload to a server 
    } 
}