Converting file:// scheme to content:// scheme

问题:

I am running to the problem with using Droid X's Files app and Astro file manager to select an image file. This two apps return the selected image with the scheme "file://" while Gallery returns the image with the scheme "content://". How do I convert the first schema to the second. Or how do I decode the image with the second format?

回答1:

You probably want to convert content:// to file://

For gallery images, try something like this:

Uri myFileUri;
Cursor cursor = context.getContentResolver().query(uri,new String[]{android.provider.MediaStore.Images.ImageColumns.DATA}, null, null, null);
if(cursor.moveToFirst())
{
    myFileUri = Uri.parse(cursor.getString(0)).getPath();
}
cursor.close

回答2:

Use ContentResolver.openInputStream() or related methods to access the byte stream. You shouldn't generally be worrying about whether it is a file: or content: URI.

http://developer.android.com/reference/android/content/ContentResolver.html#openInputStream(android.net.Uri)

回答3:

Here, the problem is that, for all files we can't have a content Uri (content://). Because content uri is for those files which are part of MediaStore. Eg: images, audio & video.

However, for supported files, we can find its absolute path. Like for images as follows-

File myimageFile = new File(path);
Uri content_uri=getImageContentUri(this,myimageFile);

The generic method is as follows.

public static Uri getImageContentUri(Context context, File imageFile) {
String filePath = imageFile.getAbsolutePath();
Cursor cursor = context.getContentResolver().query(
        MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
        new String[] { MediaStore.Images.Media._ID },
        MediaStore.Images.Media.DATA + "=? ",
        new String[] { filePath }, null);

if (cursor != null && cursor.moveToFirst()) {
    int id = cursor.getInt(cursor
            .getColumnIndex(MediaStore.MediaColumns._ID));
    Uri baseUri = Uri.parse("content://media/external/images/media");
    return Uri.withAppendedPath(baseUri, "" + id);
} else {
    if (imageFile.exists()) {
        ContentValues values = new ContentValues();
        values.put(MediaStore.Images.Media.DATA, filePath);
        return context.getContentResolver().insert(
                MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
    } else {
        return null;
    }
}}