以编程方式从Android的内置库应用程序中获取/选择图像

Question

我正在尝试从我的应用程序内部打开Gallery内置应用程序中的图像/图片。

我有一张图片的URI (图片位于SD卡上)。

你有什么意见建议？

Answer 1

这是一个完整的解决方案。我刚刚用@mad在下面的答案中提供的信息更新了这个示例代码。另外，请查看@Khobaib提供的以下解决方案，解释如何处理picasa图像。

更新

我刚刚检查了我的原始答案，并创建了一个简单的Android Studio项目，您可以从github签出并直接导入到您的系统中。

https://github.com/hanscappelle/SO-2169649

(请注意，多个文件的选择仍然需要工作)

单张图片选择

多亏了用户mad，它支持文件资源管理器中的图像。

public class BrowsePictureActivity extends Activity {

    // this is the action code we use in our intent, 
    // this way we know we're looking at the response from our own action
    private static final int SELECT_PICTURE = 1;

    private String selectedImagePath;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        findViewById(R.id.Button01)
                .setOnClickListener(new OnClickListener() {

                    public void onClick(View arg0) {

                        // in onCreate or any event where your want the user to
                        // select a file
                        Intent intent = new Intent();
                        intent.setType("image/*");
                        intent.setAction(Intent.ACTION_GET_CONTENT);
                        startActivityForResult(Intent.createChooser(intent,
                                "Select Picture"), SELECT_PICTURE);
                    }
                });
    }

    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode == RESULT_OK) {
            if (requestCode == SELECT_PICTURE) {
                Uri selectedImageUri = data.getData();
                selectedImagePath = getPath(selectedImageUri);
            }
        }
    }

    /**
     * helper to retrieve the path of an image URI
     */
    public String getPath(Uri uri) {
            // just some safety built in 
            if( uri == null ) {
                // TODO perform some logging or show user feedback
                return null;
            }
            // try to retrieve the image from the media store first
            // this will only work for images selected from gallery
            String[] projection = { MediaStore.Images.Media.DATA };
            Cursor cursor = managedQuery(uri, projection, null, null, null);
            if( cursor != null ){
                int column_index = cursor
                .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
                cursor.moveToFirst();
                String path = cursor.getString(column_index);
                cursor.close();
                return path;
            }
            // this is our fallback here
            return uri.getPath();
    }

}

选择多张图片

因为有人在评论中请求了这些信息，所以最好收集这些信息。

在intent上设置额外的参数EXTRA_ALLOW_MULTIPLE：

intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);

并在该参数的结果处理检查中：

if (Intent.ACTION_SEND_MULTIPLE.equals(data.getAction()))
        && Intent.hasExtra(Intent.EXTRA_STREAM)) {
    // retrieve a collection of selected images
    ArrayList<Parcelable> list = intent.getParcelableArrayListExtra(Intent.EXTRA_STREAM);
    // iterate over these images
    if( list != null ) {
       for (Parcelable parcel : list) {
         Uri uri = (Uri) parcel;
         // TODO handle the images one by one here
       }
   }
} 

请注意，只有接口层18+才支持此功能。

Answer 2

以下是hcpl发布的优秀代码的更新。但这也适用于OI文件管理器，astro文件管理器和媒体集(测试)。所以我猜它适用于每个文件管理器(除了上面提到的文件管理器之外，还有其他文件管理器吗？)对他写的代码做了一些修改。

public class BrowsePicture extends Activity {

    //YOU CAN EDIT THIS TO WHATEVER YOU WANT
    private static final int SELECT_PICTURE = 1;

    private String selectedImagePath;
    //ADDED
    private String filemanagerstring;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        ((Button) findViewById(R.id.Button01))
        .setOnClickListener(new OnClickListener() {

            public void onClick(View arg0) {

                // in onCreate or any event where your want the user to
                // select a file
                Intent intent = new Intent();
                intent.setType("image/*");
                intent.setAction(Intent.ACTION_GET_CONTENT);
                startActivityForResult(Intent.createChooser(intent,
                        "Select Picture"), SELECT_PICTURE);
            }
        });
    }

    //UPDATED
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode == RESULT_OK) {
            if (requestCode == SELECT_PICTURE) {
                Uri selectedImageUri = data.getData();

                //OI FILE Manager
                filemanagerstring = selectedImageUri.getPath();

                //MEDIA GALLERY
                selectedImagePath = getPath(selectedImageUri);

                //DEBUG PURPOSE - you can delete this if you want
                if(selectedImagePath!=null)
                    System.out.println(selectedImagePath);
                else System.out.println("selectedImagePath is null");
                if(filemanagerstring!=null)
                    System.out.println(filemanagerstring);
                else System.out.println("filemanagerstring is null");

                //NOW WE HAVE OUR WANTED STRING
                if(selectedImagePath!=null)
                    System.out.println("selectedImagePath is the right one for you!");
                else
                    System.out.println("filemanagerstring is the right one for you!");
            }
        }
    }

    //UPDATED!
    public String getPath(Uri uri) {
        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = managedQuery(uri, projection, null, null, null);
        if(cursor!=null)
        {
            //HERE YOU WILL GET A NULLPOINTER IF CURSOR IS NULL
            //THIS CAN BE, IF YOU USED OI FILE MANAGER FOR PICKING THE MEDIA
            int column_index = cursor
            .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            return cursor.getString(column_index);
        }
        else return null;
    }

Answer 3

hcpl的方法在KitKat之前工作得很好，但不能与DocumentsProvider API一起工作。要做到这一点，只需遵循文档提供商的官方Android教程：https://developer.android.com/guide/topics/providers/document-provider.html ->打开文档，位图部分。

我简单地使用了hcpl的代码并对其进行了扩展:如果包含图像的检索路径的文件抛出异常，我将调用此函数：

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;
}

已在Nexus 5上测试。