如何以编程方式从Android的内置图库应用程序中获取/选择图像?

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我正尝试从应用程序内部的Gallery内置应用程序中打开图像/图片,并且有图片的URI(图片位于SD卡上)。

关于这个你有什么意见?

提问于
用户回答回答于

可以查看以下的解决方案来如何处理Picasa图像

我创建了一个简单的AndroidStudio项目,你可以在GitHub查看并直接在系统上导入。

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

(请注意,多个文件选择仍然需要工作)

单幅图片选择

支持来自文件浏览器的图像:

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();
    }

}

选择多幅图片

因为有人在评论中要求提供这些信息,所以最好是收集信息。

设置额外的参数EXTRA_ALLOW_MULTIPLE关于意图:

intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);

在对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,这仅受API级别18+的支持。

用户回答回答于

可以通过以下代码显示图像和视频:

    Intent intent = new Intent();
    intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
    startActivityForResult(intent, 1);
    startActivityForResult(Intent.createChooser(intent,"Wybierz plik"), SELECT_FILE);
用户回答回答于

步骤1 打开图库来选择图片的代码:

public static final int PICK_IMAGE = 1;
private void takePictureFromGalleryOrAnyOtherFolder() 
{
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);
    startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE);
}

步骤2 onActivityResult中获取数据的代码:

 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
            super.onActivityResult(requestCode, resultCode, data);
            if (resultCode == Activity.RESULT_OK) {
               if (requestCode == PICK_IMAGE) {
                    Uri selectedImageUri = data.getData();
                    String imagePath = getRealPathFromURI(selectedImageUri);
                   //Now you have imagePath do whatever you want to do now
                 }//end of inner if
             }//end of outer if
      }

 public String getRealPathFromURI(Uri contentUri) {
        //Uri contentUri = Uri.parse(contentURI);

        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = null;
        try {
            if (Build.VERSION.SDK_INT > 19) {
                // Will return "image:x*"
                String wholeID = DocumentsContract.getDocumentId(contentUri);
                // Split at colon, use second item in the array
                String id = wholeID.split(":")[1];
                // where id is equal to
                String sel = MediaStore.Images.Media._ID + "=?";

                cursor = context.getContentResolver().query(
                        MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                        projection, sel, new String[] { id }, null);
            } else {
                cursor = context.getContentResolver().query(contentUri,
                        projection, null, null, null);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        String path = null;
        try {
            int column_index = cursor
                    .getColumnIndex(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            path = cursor.getString(column_index).toString();
            cursor.close();
        } catch (NullPointerException e) {
            e.printStackTrace();
        }
        return path;
    }
用户回答回答于

它在处理内存不足情况和图像旋转的同时返回某些提供程序的图像。它支持图库,Picasa和文件管理器,如下拉框。 用法很简单:作为输入,构造函数接收内容解析器和uri, 输出是最终的bitmap。

/**
 * Creates resized images without exploding memory. Uses the method described in android
 * documentation concerning bitmap allocation, which is to subsample the image to a smaller size,
 * close to some expected size. This is required because the android standard library is unable to
 * create a reduced size image from an image file using memory comparable to the final size (and
 * loading a full sized multi-megapixel picture for processing may exceed application memory budget).
 */

public class UserPicture {
    static int MAX_WIDTH = 600;
    static int MAX_HEIGHT = 800;
    Uri uri;
    ContentResolver resolver;
    String path;
    Matrix orientation;
    int storedHeight;
    int storedWidth;

    public UserPicture(Uri uri, ContentResolver resolver) {
        this.uri = uri;
        this.resolver = resolver;
    }

    private boolean getInformation() throws IOException {
        if (getInformationFromMediaDatabase())
            return true;

        if (getInformationFromFileSystem())
            return true;

        return false;
    }

    /* Support for gallery apps and remote ("picasa") images */
    private boolean getInformationFromMediaDatabase() {
        String[] fields = { Media.DATA, ImageColumns.ORIENTATION };
        Cursor cursor = resolver.query(uri, fields, null, null, null);

        if (cursor == null)
            return false;

        cursor.moveToFirst();
        path = cursor.getString(cursor.getColumnIndex(Media.DATA));
        int orientation = cursor.getInt(cursor.getColumnIndex(ImageColumns.ORIENTATION));
        this.orientation = new Matrix();
        this.orientation.setRotate(orientation);
        cursor.close();

        return true;
    }

    /* Support for file managers and dropbox */
    private boolean getInformationFromFileSystem() throws IOException {
        path = uri.getPath();

        if (path == null)
            return false;

        ExifInterface exif = new ExifInterface(path);
        int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION,
                                               ExifInterface.ORIENTATION_NORMAL);

        this.orientation = new Matrix();
        switch(orientation) {
            case ExifInterface.ORIENTATION_NORMAL:
                /* Identity matrix */
                break;
            case ExifInterface.ORIENTATION_FLIP_HORIZONTAL:
                this.orientation.setScale(-1, 1);
                break;
            case ExifInterface.ORIENTATION_ROTATE_180:
                this.orientation.setRotate(180);
                break;
            case ExifInterface.ORIENTATION_FLIP_VERTICAL:
                this.orientation.setScale(1, -1);
                break;
            case ExifInterface.ORIENTATION_TRANSPOSE:
                this.orientation.setRotate(90);
                this.orientation.postScale(-1, 1);
                break;
            case ExifInterface.ORIENTATION_ROTATE_90:
                this.orientation.setRotate(90);
                break;
            case ExifInterface.ORIENTATION_TRANSVERSE:
                this.orientation.setRotate(-90);
                this.orientation.postScale(-1, 1);
                break;
            case ExifInterface.ORIENTATION_ROTATE_270:
                this.orientation.setRotate(-90);
                break;
        }

        return true;
    }

    private boolean getStoredDimensions() throws IOException {
        InputStream input = resolver.openInputStream(uri);
        Options options = new Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(resolver.openInputStream(uri), null, options);

        /* The input stream could be reset instead of closed and reopened if it were possible
           to reliably wrap the input stream on a buffered stream, but it's not possible because
           decodeStream() places an upper read limit of 1024 bytes for a reset to be made (it calls
           mark(1024) on the stream). */
        input.close();

        if (options.outHeight <= 0 || options.outWidth <= 0)
            return false;

        storedHeight = options.outHeight;
        storedWidth = options.outWidth;

        return true;
    }

    public Bitmap getBitmap() throws IOException {
        if (!getInformation())
            throw new FileNotFoundException();

        if (!getStoredDimensions())
            throw new InvalidObjectException(null);

        RectF rect = new RectF(0, 0, storedWidth, storedHeight);
        orientation.mapRect(rect);
        int width = (int)rect.width();
        int height = (int)rect.height();
        int subSample = 1;

        while (width > MAX_WIDTH || height > MAX_HEIGHT) {
            width /= 2;
            height /= 2;
            subSample *= 2;
        }

        if (width == 0 || height == 0)
            throw new InvalidObjectException(null);

        Options options = new Options();
        options.inSampleSize = subSample;
        Bitmap subSampled = BitmapFactory.decodeStream(resolver.openInputStream(uri), null, options);

        Bitmap picture;
        if (!orientation.isIdentity()) {
            picture = Bitmap.createBitmap(subSampled, 0, 0, options.outWidth, options.outHeight,
                                          orientation, false);
            subSampled.recycle();
        } else
            picture = subSampled;

        return picture;
    }
}

参考资料:

用户回答回答于

以下有两个关于具有可下载源代码的图像选择器的教程:

如何创建Android图像选择器

如何在Android上选择和裁剪图像

但是,这个应用程序有时会被迫关闭,你可以通过在Manifest文件中的main activity中添加android:configChanges属性来修复它:

<activity android:name=".MainActivity"
                  android:label="@string/app_name" android:configChanges="keyboardHidden|orientation" >

用户回答回答于

hcpl的解决方案很好地支持图库中的本地图像,mad提供了更好的解决方案 - 它有助于加载OI / Astro / Dropbox图像。 但在我的应用程序中,在处理现已集成在Android Gallery中的Picasa库时,两种解决方案都失败了。

如何在运行任何操作系统版本的Android设备上使用图像选择器来获取Picase图像

以下为我的解决方法:

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);
        }
    });
}

public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK) {
        if (requestCode == SELECT_PICTURE) {
            Uri selectedImageUri = data.getData();
            Log.d("URI VAL", "selectedImageUri = " + selectedImageUri.toString());
            selectedImagePath = getPath(selectedImageUri);

            if(selectedImagePath!=null){         
                // IF LOCAL IMAGE, NO MATTER IF ITS DIRECTLY FROM GALLERY (EXCEPT PICASSA ALBUM),
                // OR OI/ASTRO FILE MANAGER. EVEN DROPBOX IS SUPPORTED BY THIS BECAUSE DROPBOX DOWNLOAD THE IMAGE 
                // IN THIS FORM - file:///storage/emulated/0/Android/data/com.dropbox.android/...
                System.out.println("local image"); 
            }
            else{
                System.out.println("picasa image!");
                loadPicasaImageFromGallery(selectedImageUri);
            }
        }
    }
}


// NEW METHOD FOR PICASA IMAGE LOAD
private void loadPicasaImageFromGallery(final Uri uri) {
    String[] projection = {  MediaColumns.DATA, MediaColumns.DISPLAY_NAME };
    Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
    if(cursor != null) {
        cursor.moveToFirst();

        int columnIndex = cursor.getColumnIndex(MediaColumns.DISPLAY_NAME);
        if (columnIndex != -1) {
            new Thread(new Runnable() {
                // NEW THREAD BECAUSE NETWORK REQUEST WILL BE MADE THAT WILL BE A LONG PROCESS & BLOCK UI
                // IF CALLED IN UI THREAD 
                public void run() {
                    try {
                        Bitmap bitmap = android.provider.MediaStore.Images.Media.getBitmap(getContentResolver(), uri);
                        // THIS IS THE BITMAP IMAGE WE ARE LOOKING FOR.
                    } catch (Exception ex) {
                        ex.printStackTrace();
                    }
                }
            }).start();
        }
    }
    cursor.close();
}


public String getPath(Uri uri) {
    String[] projection = {  MediaColumns.DATA};
    Cursor cursor = getContentResolver().query(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
        cursor.moveToFirst();
        int columnIndex = cursor.getColumnIndexOrThrow(MediaColumns.DATA);
        String filePath = cursor.getString(columnIndex);
        cursor.close();
        return filePath;
    }
    else 
        return uri.getPath();               // FOR OI/ASTRO/Dropbox etc
}

并且我对它进行了测试,在每一种情况下运行都没有问题。

用户回答回答于

假设你的SD卡目录中只有图像文件夹:

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
// tells your intent to get the contents
// opens the URI for your image directory on your sdcard
intent.setType("file:///sdcard/image/*"); 
startActivityForResult(intent, 1);

然后,你可以决定应该如何处理activitity中的内容。

以下为一个检索图像路径名的例子,可以用你的代码测试它,以确保你可以处理返回的结果,然后可以根据需求来更改代码:

protected final void onActivityResult(final int requestCode, final int
                     resultCode, final Intent i) {
    super.onActivityResult(requestCode, resultCode, i);

  // this matches the request code in the above call
  if (requestCode == 1) {
      Uri _uri = i.getData();

    // this will be null if no image was selected...
    if (_uri != null) {
      // now we get the path to the image file
     cursor = getContentResolver().query(_uri, null,
                                      null, null, null);
     cursor.moveToFirst();
     String imageFilePath = cursor.getString(0);
     cursor.close();
     }
   }

可以尝试检索图像是否正常工作,我认为问题出在SD卡上的图像的内容。

在SD卡上显示图像

如果你可以给出示例程序并成功运行,那么你应该能找出代码的解决方法。

用户回答回答于

public String getPath(Uri uri) {
    String selectedImagePath;
    //1:MEDIA GALLERY --- query from MediaStore.Images.Media.DATA
    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();
        selectedImagePath = cursor.getString(column_index);
    }else{
        selectedImagePath = null;
    }

    if(selectedImagePath == null){
        //2:OI FILE Manager --- call method: uri.getPath()
        selectedImagePath = uri.getPath();
    }
    return selectedImagePath;
}
用户回答回答于

hcpl的方法没有使用DocumentsProviderAPI,要做到这一点,必须遵循官方的Android文档提供者教程:https://developer.android.com/Guide/Subject/Providers/Document-Provider.html

->打开文档的Bitmap部分

并且对hcpl的代码进行扩展:如果检索到的图像路径的文件抛出异常,则调用此函数:

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;
}

以上代码Nexus 5上已经过测试。

用户回答回答于

以下代码适用于OI文件管理器、天文文件管理器和媒体库(测试)。因此,我想它将适用于每个文件管理器,并且我对他的代码进行了修改:

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;
    }

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