在Android中获取所选图库图片的文件路径和文件名

Question

我正在创建一个应用程序，它可以从相册中选择图片并将其上传到 web 服务。该服务需要所选图像的文件名以及文件内容的 base64 编码。我已经使用硬编码文件路径成功实现了这一点。但是，我无法获取真正的图像文件路径。我在网上阅读了一些资料并尝试了以下代码，但它对我不起作用：

 public void onActivityResult(int requestCode, int resultCode, Intent data) {
   if (resultCode == RESULT_OK) {
     Uri selectedImageUri = data.getData();
     String[] projection = {MediaStore.Images.Media.DATA};

     try {
       Cursor cursor = getContentResolver().query(selectedImageUri, projection, null, null, null);
       cursor.moveToFirst();

       int columnIndex = cursor.getColumnIndex(projection[0]);
       String picturePath = cursor.getString(columnIndex);
       cursor.close();
       Log.d("Picture Path", picturePath);
     }
     catch(Exception e) {
       Log.e("Path Error", e.toString());
     }
   }
 }

我遇到了这个错误:

java.lang.NullPointerException

编辑

忘记提到了我正在使用KitKat。看起来我的问题与KitKat有关。我找到了这个（见下文），它帮助我让我的应用程序正常工作：

Android Gallery on KitKat返回不同的Uri以用于Intent.ACTION_GET_CONTENT

- amburnside

---

请将您的Logcat堆栈跟踪粘贴在此处。 - Praveen Sharma

你是否收到了空的“Intent数据”？ - Praveen Sharma

@PraveenSharma，你能帮我解决这个详细的问题并添加悬赏吗？非常感谢：https://stackoverflow.com/questions/62783444/why-does-multipart-pdf-is-not-able-to-upload-in-api-after-nougat-using-retrofit - Priyanka Singh

Answer 1

虽然来晚了一点，但这是我的代码，希望能有所帮助。

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK) {
        Uri selectedImageUri = data.getData( );
        String picturePath = getPath( getActivity( ).getApplicationContext( ), selectedImageUri );
        Log.d("Picture Path", picturePath);
    }
}

public static String getPath( Context context, Uri uri ) {
    String result = null;
    String[] proj = { MediaStore.Images.Media.DATA };
    Cursor cursor = context.getContentResolver( ).query( uri, proj, null, null, null );
    if(cursor != null){
        if ( cursor.moveToFirst( ) ) {
            int column_index = cursor.getColumnIndexOrThrow( proj[0] );
            result = cursor.getString( column_index );
        }
        cursor.close( );
    }
    if(result == null) {
        result = "Not found";
    }
    return result;
}

- Matthew Carpenter

---

非常好用。谢谢。 - Christopher Mills

对我来说未发现错误。 - ajay dhadhal

如果图像没有保存，@ajaydhadhal的getPath将返回未找到。请检查URI路径并定位文件以查看其是否存在。 - Matthew Carpenter

返回“未找到”； - hkchakladar

是啊，为什么找不到呢？ - gumuruh

@gumuruh，也许你要找的位置从来没有保存过你的图片。 - Matthew Carpenter

Answer 2

请使用以下代码：

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

    if (resultCode == RESULT_OK) {

     Uri selectedImageUri = data.getData();
     String s = getRealPathFromURI(selectedImageUri);
     editText1.setText(s);
}
}

以下是你的getRealPathFromURI函数。

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

- InnocentKiller

---

Logcat显示如下内容：E/PathError(29354): java.lang.IllegalArgumentException: column '_data' 不存在。 - amburnside

如果您只想显示完整路径，则可以使用getRealPathFromURI函数与现有代码一起使用，而不是使用完整代码。 - InnocentKiller

我稍微修改了一下代码，现在应该可以工作了，请再试一次。 - InnocentKiller

你能否发布你的完整Activity类代码以及Logcat？ - InnocentKiller

getRealPathFromURI 总是返回 null - hkchakladar

Answer 3

试试这个：

Uri selectedImageURI = data.getData();
imageFile = new File(getRealPathFromURI(selectedImageURI));

And

    private String getRealPathFromURI(Uri contentURI) {
    Cursor cursor = getContentResolver().query(contentURI, null, null, null, null);
    if (cursor == null) { // Source is Dropbox or other similar local file path
        return contentURI.getPath();
    } else { 
        cursor.moveToFirst(); 
        int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA); 
        return cursor.getString(idx); 
    }
}

- Virag Brahme

---

我尝试了你的实现，但它也失败了。以下是从logcat中得到的信息：E/PathError(27809): java.lang.IllegalStateException: Couldn't read row 0, col -1 from CursorWindow. 在访问数据之前，请确保正确初始化Cursor。 - amburnside

Answer 4

public class RealFilePath {
    /**
     * Get a file path from a Uri. This will get the the path for Storage Access
     * Framework Documents, as well as the _data field for the MediaStore and
     * other file-based ContentProviders.
     *
     * @param context The context.
     * @param uri     The Uri to query
     */
    public static String getPath(final Context context, final Uri uri) {

        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

        // DocumentProvider
        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
            // ExternalStorageProvider
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }

                // TODO handle non-primary volumes
            }
            // DownloadsProvider
            else if (isDownloadsDocument(uri)) {

                final String id = DocumentsContract.getDocumentId(uri);
                final Uri contentUri = ContentUris.withAppendedId(
                    Uri.parse("content://downloads/public_downloads"), Long.valueOf(id)
                );

                return getDataColumn(context, contentUri, null, null);
            }
            // MediaProvider
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                }
                else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                }
                else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }

                final String selection = "_id=?";
                final String[] selectionArgs = new String[]{
                    split[1]
                };

                return getDataColumn(context, contentUri, selection, selectionArgs);
            }
        }
        // MediaStore (and general)
        else if ("content".equalsIgnoreCase(uri.getScheme())) {

            // Return the remote address
            if (isGooglePhotosUri(uri))
                return uri.getLastPathSegment();

            return getDataColumn(context, uri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }

        return null;
    }

    /**
     * Get the value of the data column for this Uri. This is useful for
     * MediaStore Uris, and other file-based ContentProviders.
     *
     * @param context       The context.
     * @param uri           The Uri to query.
     * @param selection     (Optional) Filter used in the query.
     * @param selectionArgs (Optional) Selection arguments used in the query.
     * @return The value of the _data column, which is typically a file path.
     */
     public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {

        Cursor cursor = null;
        final String column = "_data";
        final String[] projection = {
            column
        };

        try {
            cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
                null);
            if (cursor != null && cursor.moveToFirst()) {
                final int index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(index);
            }
         }
         finally {
             if (cursor != null)
                 cursor.close();
         }
        return null;
    }


   /**
    * @param uri The Uri to check.
    * @return Whether the Uri authority is ExternalStorageProvider.
    */
    public static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getAuthority());
    }

   /**
    * @param uri The Uri to check.
    * @return Whether the Uri authority is DownloadsProvider.
    */
    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }

   /**
    * @param uri The Uri to check.
    * @return Whether the Uri authority is MediaProvider.
    */
    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }

   /**
    * @param uri The Uri to check.
    * @return Whether the Uri authority is Google Photos.
    */
    public static boolean isGooglePhotosUri(Uri uri) {
        return "com.google.android.apps.photos.content".equals(uri.getAuthority());
    }
}

- manas.abrol

---

我不知道这个美妙的代码片段来自哪里，但在StackOverflow上，我们通常会回答问题并提供代码以及合理的解释。偶尔还会附上原始来源的URL。 - Ezequiel Adrian

Answer 5

如果你和我一样没有本地文件可用，例如你想让用户拍照并上传图片，那么这就是如何做到的。 我在Java方面是个新手，但我有很多编程经验。 Stackoverflow帮了我很多忙，现在轮到我回报社区了。

在类活动中，你需要声明这两个项目。 假设你有一个工作的上传类和PHP脚本。

注意，我没有考虑所有不同的API。我正在使用Java编译器1.7和API范围为10到18。

public class Yourproject extends Activity {
File imageFile;
File imageFileName;

//This part is needed for decoding the path adres.

 private String getRealPathFromURI(Uri contentURI) {
            String result;
            Cursor cursor = getContentResolver().query(contentURI, null, null, null, null);
            if (cursor == null) { // Source is Dropbox or other similar local file path
                result = contentURI.getPath();
            } else { 
                cursor.moveToFirst(); 
                int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.BUCKET_DISPLAY_NAME); 
                result = cursor.getString(idx);
                cursor.close();
            }
            return result;
        }

//This is needed for the path name, now you might just want to use one decoding script depending on //your class in total.
//In my case this was the way to go.
//To use one single addres use this line ImageColumns.DATA in the int idx declaration.

        private String getRealPathFromNAME(Uri contentNAME) {
            String result;
            Cursor cursor = getContentResolver().query(contentNAME, null, null, null, null);
            if (cursor == null) { // Source is Dropbox or other similar local file path
                result = contentNAME.getPath();
            } else { 
                cursor.moveToFirst(); 
                int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DISPLAY_NAME); 
                result = cursor.getString(idx);
                cursor.close();
            }
            return result;
        }

//Then under protected void onCreate(Bundle savedInstanceState) you place this code to get 
//the image and process it.
@Override
protected void onCreate(Bundle savedInstanceState) {
        //declare the ImageView
        final ImageView inputPicture = (ImageView) findViewById(R.id.imageView2);

        inputPicture.setImageURI((Uri) getIntent().getExtras().get("picture"));
        //here where recieve the image from last page "Putextra" method


        try {
            //here we will get the data and proces it trough to get the real 
            //address for uploading.
            //This is send from a other activity with a Intent.EXTRA_STREAM
            //The code looks like this:
            /*********"Putextra"*********/
            //final ImageView iv = (ImageView) findViewById(R.id.imageView1);
            //final Uri thumb = (Uri) getIntent().getExtras().get(Intent.EXTRA_STREAM);
            //iv.setImageURI(thumb);

            //Sending it to the next activity

            //it.putExtra("picture", thumb);    
            /*********"Putextra"*********/

            Uri fileUri = (Uri) getIntent().getExtras().get("picture");
            //get 
            //Uri fileName = (Uri) getIntent().getExtras().get("picture");
            //get
            imageFile = new File(getRealPathFromURI(fileUri));
            //send
            imageFileName = new File(getRealPathFromNAME(fileUri));
            //send
            //i got a exeption Uri fileName, use fileUri twice..
        } catch (Exception e2) {
            // TODO Auto-generated catch block
            e2.printStackTrace();
        }
        //here we will declare the name for furter processing.
        final File uploadFilePath = imageFile;
        final File uploadFileName = imageFileName;


}

其余的部分就交给你了，如果你看到这里，我相信你能完成。

- Peter Gruppelaar

Answer 6

希望这能对你有所帮助。

 if (Build.VERSION.SDK_INT <19){

    Intent intent = new Intent(); 
    intent.setType("image/jpeg");
    intent.setAction(Intent.ACTION_GET_CONTENT);
    startActivityForResult(Intent.createChooser(intent, 
    getResources().getString(R.string.select_picture)),GALLERY_INTENT_CALLED);

 }else{

      Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
      intent.addCategory(Intent.CATEGORY_OPENABLE);
      intent.setType("image/jpeg");
      startActivityForResult(intent, GALLERY_KITKAT_INTENT_CALLED);
 }

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

      super.onActivityResult(requestCode, resultCode, data);
      if (resultCode != Activity.RESULT_OK) return;
      if (null == data) return;
      Uri originalUri = null;

      if (requestCode == GALLERY_INTENT_CALLED) {
           originalUri = data.getData();
      } 
      else if (requestCode == GALLERY_KITKAT_INTENT_CALLED) {
           originalUri = data.getData();
           final int takeFlags = data.getFlags()
            & (Intent.FLAG_GRANT_READ_URI_PERMISSION
            | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);

            // Check for the freshest data.
            getContentResolver().takePersistableUriPermission(originalUri,    takeFlags);
      }
      loadSomeStreamAsynkTask(originalUri);
}

- saeed

Answer 7

试试这个，

 file = new File(getPath(outputFileUri));


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

- Murali Ganesan

Answer 8

尝试这个来获取数据以及文件路径并插入到文件夹中。

public void onActivityResult(int requestCode, int resultCode, Intent data)
{
    super.onActivityResult(requestCode, resultCode, data);
    try {
        if (resultCode == RESULT_OK)
        {
            nav = data.getData();
            String[] projection = { MediaStore.Images.Media.DATA };
            Cursor cursor = managedQuery(nav, projection, null, null, null);
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            String path= cursor.getString(column_index);
            Toast.makeText(getApplicationContext(), path, 500).show();
            mBitmap = android.provider.MediaStore.Images.Media.getBitmap(getContentResolver(), nav);
            insert(mBitmap);

            if (mBitmap != null) {  
                mBitmap.recycle();  
                mBitmap = null;  
            } 
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}
private void insert(Bitmap finalBitmap) {
    File myDir=new File("/sdcard/saved_images");
    myDir.mkdirs();

    Random generator = new Random();
    int n = 10000;
    n = generator.nextInt(n);
    String fname = "Image-"+ n +".jpg";
    File file = new File (myDir, fname);
    if (file.exists ()) file.delete (); 
    try {
        FileOutputStream out = new FileOutputStream(file);
        finalBitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
        out.flush();
        out.close();
        File dstFile = new File(file.getParent(), "." + file.getName());
        file.renameTo(dstFile);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

- Naveeen Kumar