如何挑选从画廊（SD卡），我的应用程序的图像？

StackOverflow https://stackoverflow.com/questions/2507898

题

这个问题最初提出的Android 1.6。

我在我的应用程序工作在照片上的选项。

我有一个按钮，在我的活性的ImageView的。当我点击该按钮会重定向到画廊和我将能够选择一个图像。所选择的图像会出现在我的ImageView。

有帮助吗？

解决方案

更新的答案，近5年以后：

在原始的应答中的代码不再工作可靠，例如得自各种来源的图像有时会与不同的内容的URI，即content://而非file://返回。更好的方法是简单地使用context.getContentResolver().openInputStream(intent.getData())，因为这会返回一个InputStream，你可以处理随你选。

例如，BitmapFactory.decodeStream()完美地工作在这种情况下，因为也可以再使用选项和inSampleSize场下采样放大图，避免存储器的问题。

然而，事情像谷歌驱动器返回URI来已经不算真正到过图片下载呢。因此就需要在后台线程执行getContentResolver（）的代码。

原来的答复：

其他答案解释如何发送的意图，但他们并没有很好地解释了如何处理响应。下面是关于如何做到这一点的一些示例代码：

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

    switch(requestCode) { 
    case REQ_CODE_PICK_IMAGE:
        if(resultCode == RESULT_OK){  
            Uri selectedImage = imageReturnedIntent.getData();
            String[] filePathColumn = {MediaStore.Images.Media.DATA};

            Cursor cursor = getContentResolver().query(
                               selectedImage, filePathColumn, null, null, null);
            cursor.moveToFirst();

            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            String filePath = cursor.getString(columnIndex);
            cursor.close();


            Bitmap yourSelectedImage = BitmapFactory.decodeFile(filePath);
        }
    }
}

在这之后，你就存储在“yourSelectedImage”做你想要与任何所选择的图像。此代码通过获取在ContentResolver的数据库中的图像的位置，但其本身是不够的。每个图像具有约18的信息的列，从它的文件路径向照片拍摄地点的GPS坐标“最后修改日期”，尽管许多字段都没有实际使用。

要节省时间，因为你实际上并不需要其他字段，光标搜索与过滤器来完成。这个过滤器可以通过指定要列，MediaStore.Images.Media.DATA，这是路径的名称，然后给予该字符串[]光标查询。与路径光标查询返回，但你不知道它，直到你使用columnIndex代码列。简单地获取基于它的名字，同一个在过滤过程中使用的列数。一旦你得到了，你终于能够将图像解码与代码我给的最后一行的位图。

其他提示

private static final int SELECT_PHOTO = 100;

开始意图

Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
photoPickerIntent.setType("image/*");
startActivityForResult(photoPickerIntent, SELECT_PHOTO);

处理结果

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) { 
    super.onActivityResult(requestCode, resultCode, imageReturnedIntent); 

    switch(requestCode) { 
    case SELECT_PHOTO:
        if(resultCode == RESULT_OK){  
            Uri selectedImage = imageReturnedIntent.getData();
            InputStream imageStream = getContentResolver().openInputStream(selectedImage);
            Bitmap yourSelectedImage = BitmapFactory.decodeStream(imageStream);
        }
    }
}

另外，您也可以下采样图像，以避免内存不足的错误。

private Bitmap decodeUri(Uri selectedImage) throws FileNotFoundException {

        // Decode image size
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImage), null, o);

        // The new size we want to scale to
        final int REQUIRED_SIZE = 140;

        // Find the correct scale value. It should be the power of 2.
        int width_tmp = o.outWidth, height_tmp = o.outHeight;
        int scale = 1;
        while (true) {
            if (width_tmp / 2 < REQUIRED_SIZE
               || height_tmp / 2 < REQUIRED_SIZE) {
                break;
            }
            width_tmp /= 2;
            height_tmp /= 2;
            scale *= 2;
        }

        // Decode with inSampleSize
        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize = scale;
        return BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImage), null, o2);

    }

您必须启动画廊意图的结果。

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

然后，在onActivityForResult，呼叫intent.getData()以获取图像的URI。然后，你需要从ContentProvider的获取图像。

下面是用于图像的测试代码和video.It将为所有API工作小于19并大于19为好。

图像：

if (Build.VERSION.SDK_INT <= 19) {
                        Intent i = new Intent();
                        i.setType("image/*");
                        i.setAction(Intent.ACTION_GET_CONTENT);
                        i.addCategory(Intent.CATEGORY_OPENABLE);
                        startActivityForResult(i, 10);
                    } else if (Build.VERSION.SDK_INT > 19) {
                        Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                        startActivityForResult(intent, 10);
                    }

视频：

if (Build.VERSION.SDK_INT <= 19) {
                        Intent i = new Intent();
                        i.setType("video/*");
                        i.setAction(Intent.ACTION_GET_CONTENT);
                        i.addCategory(Intent.CATEGORY_OPENABLE);
                        startActivityForResult(i, 20);
                    } else if (Build.VERSION.SDK_INT > 19) {
                        Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Video.Media.EXTERNAL_CONTENT_URI);
                        startActivityForResult(intent, 20);
                    }    


         @Override
        public void onActivityResult(int requestCode, int resultCode, Intent data) {
            super.onActivityResult(requestCode, resultCode, data);
            if (resultCode == Activity.RESULT_OK) {

                if (requestCode == 10) {
                    Uri selectedImageUri = data.getData();
                    String selectedImagePath = getRealPathFromURI(selectedImageUri);
                } else if (requestCode == 20) {
                    Uri selectedVideoUri = data.getData();
                    String selectedVideoPath = getRealPathFromURI(selectedVideoUri);
                }
    }
}
         public String getRealPathFromURI(Uri uri) {
                if (uri == null) {
                    return null;
                }
                String[] projection = {MediaStore.Images.Media.DATA};
                Cursor cursor = getActivity().getContentResolver().query(uri, projection, null, null, null);
                if (cursor != null) {
                    int column_index = cursor
                            .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
                    cursor.moveToFirst();
                    return cursor.getString(column_index);
                }
                return uri.getPath();
            }

这样做以启动画廊和允许用户选择一个图像：

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
startActivityForResult(intent, IMAGE_PICK);

然后在您onActivityResult()使用时返回到设置在您的ImageView图像的图像的URI。

public class EMView extends Activity {
ImageView img,img1;
int column_index;
  Intent intent=null;
// Declare our Views, so we can access them later
String logo,imagePath,Logo;
Cursor cursor;
//YOU CAN EDIT THIS TO WHATEVER YOU WANT
private static final int SELECT_PICTURE = 1;

 String selectedImagePath;
//ADDED
 String filemanagerstring;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    img= (ImageView)findViewById(R.id.gimg1);



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

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

            //MEDIA GALLERY
            selectedImagePath = getPath(selectedImageUri);


            img.setImageURI(selectedImageUri);

           imagePath.getBytes();
           TextView txt = (TextView)findViewById(R.id.title);
           txt.setText(imagePath.toString());


           Bitmap bm = BitmapFactory.decodeFile(imagePath);

          // img1.setImageBitmap(bm);



        }

    }

}

//UPDATED!
public String getPath(Uri uri) {
String[] projection = { MediaColumns.DATA };
Cursor cursor = managedQuery(uri, projection, null, null, null);
column_index = cursor
        .getColumnIndexOrThrow(MediaColumns.DATA);
cursor.moveToFirst();
 imagePath = cursor.getString(column_index);

return cursor.getString(column_index);
}

}

public class BrowsePictureActivity extends Activity {
private static final int SELECT_PICTURE = 1;

private String selectedImagePath;

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) {

                    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);
        }
    }
}

public String getPath(Uri uri) {

        if( uri == null ) {
            return null;
        }

        // 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();
            return cursor.getString(column_index);
        }

        return uri.getPath();
}

}

由于种种原因，都在这个线程的答案，在onActivityResult()尝试后处理接收到的Uri例如获取图像的真实路径，然后使用BitmapFactory.decodeFile(path)得到Bitmap。

此步骤是不必要的。该ImageView类有一个叫做setImageURI(uri)方法。您通过URI它和你应该做的。

Uri imageUri = data.getData();
imageView.setImageURI(imageUri);

对于一个完整的工作例如，你可以看看这里：的 http://androidbitmaps.blogspot.com/2015/04/loading-images-in-android-part-iii-pick.html

PS：点击 获取Bitmap在一个单独的变量是有意义在待加载的图像的情况下是太大而不适合在存储器中，和一个分频操作是必要的，以防止OurOfMemoryError，像示于@siamii答案。

呼叫chooseImage方法类似 - 

public void chooseImage(ImageView v)
{
    Intent intent = new Intent(Intent.ACTION_PICK);
    intent.setType("image/*");
    startActivityForResult(intent, SELECT_PHOTO);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
    // TODO Auto-generated method stub
    super.onActivityResult(requestCode, resultCode, imageReturnedIntent);

    if(imageReturnedIntent != null)
    {
        Uri selectedImage = imageReturnedIntent.getData();
    switch(requestCode) { 
    case SELECT_PHOTO:
        if(resultCode == RESULT_OK)
        {
            Bitmap datifoto = null;
            temp.setImageBitmap(null);
            Uri picUri = null;
            picUri = imageReturnedIntent.getData();//<- get Uri here from data intent
             if(picUri !=null){
               try {
                   datifoto = android.provider.MediaStore.Images.Media.getBitmap(this.getContentResolver(),                                 picUri);
                   temp.setImageBitmap(datifoto);
               } catch (FileNotFoundException e) {
                  throw new RuntimeException(e);
               } catch (IOException e) {
                  throw new RuntimeException(e);
               } catch (OutOfMemoryError e) {
                Toast.makeText(getBaseContext(), "Image is too large. choose other", Toast.LENGTH_LONG).show();
            }

        }
        }
        break;

}
    }
    else
    {
        //Toast.makeText(getBaseContext(), "data null", Toast.LENGTH_SHORT).show();
    }
}

#initialize in main activity 
    path = Environment.getExternalStorageDirectory()
            + "/images/make_machine_example.jpg"; #
     ImageView image=(ImageView)findViewById(R.id.image);
 //--------------------------------------------------||

 public void FromCamera(View) {

    Log.i("camera", "startCameraActivity()");
    File file = new File(path);
    Uri outputFileUri = Uri.fromFile(file);
    Intent intent = new Intent(
            android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
    intent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
    startActivityForResult(intent, 1);

}

public void FromCard() {
    Intent i = new Intent(Intent.ACTION_PICK,
            android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
    startActivityForResult(i, 2);
}

 protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == 2 && resultCode == RESULT_OK
            && null != data) {

        Uri selectedImage = data.getData();
        String[] filePathColumn = { MediaStore.Images.Media.DATA };

        Cursor cursor = getContentResolver().query(selectedImage,
                filePathColumn, null, null, null);
        cursor.moveToFirst();

        int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
        String picturePath = cursor.getString(columnIndex);
        cursor.close();

        bitmap = BitmapFactory.decodeFile(picturePath);
        image.setImageBitmap(bitmap);

        if (bitmap != null) {
            ImageView rotate = (ImageView) findViewById(R.id.rotate);

        }

    } else {

        Log.i("SonaSys", "resultCode: " + resultCode);
        switch (resultCode) {
        case 0:
            Log.i("SonaSys", "User cancelled");
            break;
        case -1:
            onPhotoTaken();
            break;

        }

    }

}

protected void onPhotoTaken() {
    // Log message
    Log.i("SonaSys", "onPhotoTaken");
    taken = true;
    imgCapFlag = true;
    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inSampleSize = 4;
    bitmap = BitmapFactory.decodeFile(path, options);
    image.setImageBitmap(bitmap);


}
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