将内容：// URI转换为Android 4.4中的实际路径

Question

我尝试了一个解决方案（见下文）工作正常，但在Android 4.4中调用startActivityForResult()会调出一个名为“Open from”的活动，其中包含“Recent”，“Images”，“Downloads”以及几个可供挑选的应用程序。当我选择“图像”并尝试解析返回的内容URI（使用下面的代码）时，对cursor.getString()的调用将返回null。如果我使用Gallery应用程序选择完全相同的文件，cursor.getString()将返回文件路径。我只在API级别16和19中对此进行了测试。一切都按照预期的方式运行。至于19，我必须选择图库或其他应用程序，否则它不起作用。

private String getRealPathFromURI(Context context, Uri contentUri) {
    Cursor cursor = null;
    try { 
        String[] proj = { MediaStore.Images.Media.DATA };
        cursor = context.getContentResolver().query(contentUri,  proj, null, null, null);
        int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        String path = cursor.getString(column_index);

        return path;
    } finally {
        if (cursor != null) {
            cursor.close();
        }
    }
}

Answer 1

这将从MediaProvider，DownloadsProvider和ExternalStorageProvider获取文件路径，同时回退到您提到的非官方ContentProvider方法。

   /**
 * 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.
 * @author paulburke
 */
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 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 column_index = cursor.getColumnIndexOrThrow(column);
            return cursor.getString(column_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());
}

source aFileChooser

Answer 2

  

将内容：// URI转换为Android 4.4中的实际路径

在任何Android版本上都没有可靠的方法。 content:// Uri不必代表文件系统上的文件，更不用说您可以访问的文件了。

Android 4.4提供存储框架的更改只会增加您遇到content:// Uri值的频率。

如果您获得content:// Uri，请使用ContentResolver以及openInputStream()和openOutputStream()等方法使用它。

Answer 3

我也一直面临这个问题，但在我的情况下，我想要做的是指定一个具体的Uri到画廊，以便我以后可以使用裁剪。看起来在KitKat的新文档浏览器中我们不能再这样做了，除非你在导航抽屉中选择galery，并且，就像你说的那样，直接从那里打开图像或文件。

在Uri的情况下，您仍然可以从文档浏览器打开时检索路径。

    Intent dataIntent= new Intent(Intent.ACTION_GET_CONTENT);
    dataIntent.setType("image/*"); //Or whatever type you need

然后在onActivityResult：

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == ACTIVITY_SELECT_IMAGE && resultCode == RESULT_OK) {
        myUri = data.getData();
        String path = myUri.getPath();
        openPath(myUri);

    }
}

如果您需要打开包含该路径的文件，您只需使用内容解析器：

public void openPath(Uri uri){
    InputStream is = null;
    try {
        is = getContentResolver().openInputStream(uri);
        //Convert your stream to data here
        is.close();

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

Answer 4

在a Google API中介绍。你可以试试这个：

private Bitmap getBitmapFromUri(Uri uri) throws IOException {
    ParcelFileDescriptor parcelFileDescriptor =
            getContentResolver().openFileDescriptor(uri, "r");
    FileDescriptor fileDescriptor = parcelFileDescriptor.getFileDescriptor();
    Bitmap image = BitmapFactory.decodeFileDescriptor(fileDescriptor);
    parcelFileDescriptor.close();
    return image;
}

Answer 5

如果您确实需要文件路径。首先，使用ContentResolver获取数据。然后，您可以将数据保存到临时文件并使用该路径。

（我必须在函数参数中使用带有File对象的库。）

Answer 6

感谢@FireBear，我现在修改了答案，我们将获得媒体文件的路径

String filePath = saveBitmap（activity，getBitmapFromUri（imageUri），＆＃34; tmpFile＆＃34;）。getPath（）;

private Bitmap getBitmapFromUri(Context context, Uri uri) throws IOException {
        ParcelFileDescriptor parcelFileDescriptor =
                context.getContentResolver().openFileDescriptor(uri, "r");
        FileDescriptor fileDescriptor = parcelFileDescriptor.getFileDescriptor();
        Bitmap image = BitmapFactory.decodeFileDescriptor(fileDescriptor);
        parcelFileDescriptor.close();
        return image;
    }

    private File saveBitmap(Context context, Bitmap bitmap, String name) {
        File filesDir = context.getFilesDir();
        File imageFile = new File(filesDir, name + ".jpg");
        OutputStream os;
        try {
            os = new FileOutputStream(imageFile);
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os);
            os.flush();
            os.close();
        } catch (Exception e) {
            //Log.e(getClass().getSimpleName(), "Error writing bitmap", e);
        }
        return imageFile;
    }

Answer 7

我知道它本身并不能回答问题，但正如@CommonsWare 难过的那样，SAF 并不打算使用这种方式。

可能的一种选择是在应用程序的外部文件目录中创建文件的副本，使用它然后将其删除。

public File createFileCopy(Context context, DocumentFile file) {

        if (file == null || !file.exists() || file.getName() == null) {
            throw new IllegalArgumentException("The file must no be null, and must exist, and must have a name.");
        }

        File fileCopy = new File(context.getExternalFilesDir(null).getAbsolutePath(), file.getName());

        try {

            android.os.FileUtils.copy(openFileInputStream(file), new FileOutputStream(fileCopy));

            return fileCopy;

        } catch (Exception e) {
          // do whateveer you want with this exceeption
            e.printStackTrace();
        }
        return null;
    }

Answer 8

从Uri获取文件路径： - 我创建了一个Util类，它将获取 存储访问框架文档 的路径，以及 MediaStore 的_data字段以及其他 基于文件的ContentProviders 。

ConvertUriToFilePath： -

import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import android.support.annotation.RequiresApi;

public class ConvertUriToFilePath {
    /**
     * 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.
     */
    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    public static String getPathFromURI(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())) {

        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);


        //  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 column_index = cursor.getColumnIndexOrThrow(column);
            return cursor.getString(column_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());
}

}

示例代码：

// Just call this function of ConvertUriToFilePath class and it will return full path of file URI.

 String actualFilepath= ConvertUriToFilePath.getPathFromURI(activity,tempUri);