以下是保罗·伯克的回答的更新版本。在Android 4.4 (KitKat)以下的版本中，我们没有DocumentsContract类。

为了在KitKat以下的版本上工作，创建这个类:

public class DocumentsContract {
    private static final String DOCUMENT_URIS =
        "com.android.providers.media.documents " +
        "com.android.externalstorage.documents " +
        "com.android.providers.downloads.documents " +
        "com.android.providers.media.documents";

    private static final String PATH_DOCUMENT = "document";
    private static final String TAG = DocumentsContract.class.getSimpleName();

    public static String getDocumentId(Uri documentUri) {
        final List<String> paths = documentUri.getPathSegments();
        if (paths.size() < 2) {
            throw new IllegalArgumentException("Not a document: " + documentUri);
        }

        if (!PATH_DOCUMENT.equals(paths.get(0))) {
            throw new IllegalArgumentException("Not a document: " + documentUri);
        }
        return paths.get(1);
    }

    public static boolean isDocumentUri(Uri uri) {
        final List<String> paths = uri.getPathSegments();
        Logger.v(TAG, "paths[" + paths + "]");
        if (paths.size() < 2) {
            return false;
        }
        if (!PATH_DOCUMENT.equals(paths.get(0))) {
            return false;
        }
        return DOCUMENT_URIS.contains(uri.getAuthority());
    }
}

下面的答案是https://stackoverflow.com/users/3082682/cvizv在一个已经不存在的页面上写的，因为他没有足够的代表来回答一个问题，我把它贴出来。没有我的功劳。

public String getImagePath(Uri uri){
   Cursor cursor = getContentResolver().query(uri, null, null, null, null);
   cursor.moveToFirst();
   String document_id = cursor.getString(0);
   document_id = document_id.substring(document_id.lastIndexOf(":")+1);
   cursor.close();

   cursor = getContentResolver().query( 
   android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
   null, MediaStore.Images.Media._ID + " = ? ", new String[]{document_id}, null);
   cursor.moveToFirst();
   String path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
   cursor.close();

   return path;
}

编辑:代码上有一个流程;如果设备有多个外部存储(外部sd卡，外部usb等)，以上代码将不能工作在非主存储。

我也有同样的问题。我需要的文件名，以便能够上传到一个网站。

如果我将意图改为PICK，这对我来说是有效的。 这在AVD for Android 4.4和AVD for Android 2.1中进行了测试。

增加权限READ_EXTERNAL_STORAGE

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

改变意图:

Intent i = new Intent(
  Intent.ACTION_PICK,
  android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI
  );
startActivityForResult(i, 66453666);

/* OLD CODE
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(
  Intent.createChooser( intent, "Select Image" ),
  66453666
  );
*/

我不需要改变我的代码得到实际的路径:

// Convert the image URI to the direct file system path of the image file
 public String mf_szGetRealPathFromURI(final Context context, final Uri ac_Uri )
 {
     String result = "";
     boolean isok = false;

     Cursor cursor = null;
      try { 
        String[] proj = { MediaStore.Images.Media.DATA };
        cursor = context.getContentResolver().query(ac_Uri,  proj, null, null, null);
        int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        result = cursor.getString(column_index);
        isok = true;
      } finally {
        if (cursor != null) {
          cursor.close();
        }
      }

      return isok ? result : "";
 }

以下是保罗·伯克的回答的更新版本。在Android 4.4 (KitKat)以下的版本中，我们没有DocumentsContract类。

为了在KitKat以下的版本上工作，创建这个类:

public class DocumentsContract {
    private static final String DOCUMENT_URIS =
        "com.android.providers.media.documents " +
        "com.android.externalstorage.documents " +
        "com.android.providers.downloads.documents " +
        "com.android.providers.media.documents";

    private static final String PATH_DOCUMENT = "document";
    private static final String TAG = DocumentsContract.class.getSimpleName();

    public static String getDocumentId(Uri documentUri) {
        final List<String> paths = documentUri.getPathSegments();
        if (paths.size() < 2) {
            throw new IllegalArgumentException("Not a document: " + documentUri);
        }

        if (!PATH_DOCUMENT.equals(paths.get(0))) {
            throw new IllegalArgumentException("Not a document: " + documentUri);
        }
        return paths.get(1);
    }

    public static boolean isDocumentUri(Uri uri) {
        final List<String> paths = uri.getPathSegments();
        Logger.v(TAG, "paths[" + paths + "]");
        if (paths.size() < 2) {
            return false;
        }
        if (!PATH_DOCUMENT.equals(paths.get(0))) {
            return false;
        }
        return DOCUMENT_URIS.contains(uri.getAuthority());
    }
}

我们需要在我们早期的onActivityResult()的图库选择器代码中做以下更改/修复，以便在Android 4.4 (KitKat)和所有其他早期版本上无缝运行。

Uri selectedImgFileUri = data.getData();

if (selectedImgFileUri == null ) {

    // The user has not selected any photo
}

try {

   InputStream input = mActivity.getContentResolver().openInputStream(selectedImgFileUri);
   mSelectedPhotoBmp = BitmapFactory.decodeStream(input);
}
catch (Throwable tr) {

    // Show message to try again
}

试试这个:

//KITKAT
i = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, CHOOSE_IMAGE_REQUEST);

在onActivityResult中使用以下命令:

Uri selectedImageURI = data.getData();
input = c.getContentResolver().openInputStream(selectedImageURI);
BitmapFactory.decodeStream(input , null, opts);