安卓:如何将从图库中选择的照片设置为位图

Question

我要求用户通过代码作为这里的侦听器访问图库：

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

但是，我对如何为所选照片设置变量感到困惑。

我将代码放在哪里以将变量设置为所选照片？

谢谢:)

Answer 1

首先，您必须覆盖onActivityResult以获取文件所选图像的uri

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
    if (requestCode == SELECT_PHOTO) {
        if (resultCode == RESULT_OK) {
            if (intent != null) {
                // Get the URI of the selected file
                final Uri uri = intent.getData();
                useImage(uri);                   
              }
        }
       super.onActivityResult(requestCode, resultCode, intent);
    }
}

然后定义useImage(Uri)以使用图像

void useImage(Uri uri)
{
 Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), uri);
 //use the bitmap as you like
 imageView.setImageBitmap(bitmap);
}

Answer 2

你可以这样做。

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    // Here we need to check if the activity that was triggers was the Image Gallery.
    // If it is the requestCode will match the LOAD_IMAGE_RESULTS value.
    // If the resultCode is RESULT_OK and there is some data we know that an image was picked.
    if (requestCode == LOAD_IMAGE_RESULTS && resultCode == RESULT_OK && data != null) {
        // Let's read picked image data - its URI
        Uri pickedImage = data.getData();
        // Let's read picked image path using content resolver
        String[] filePath = { MediaStore.Images.Media.DATA };
        Cursor cursor = getContentResolver().query(pickedImage, filePath, null, null, null);
        cursor.moveToFirst();
        String imagePath = cursor.getString(cursor.getColumnIndex(filePath[0]));
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inPreferredConfig = Bitmap.Config.ARGB_8888;
        Bitmap bitmap = BitmapFactory.decodeFile(imagePath, options);
         // Do something with the bitmap

        // At the end remember to close the cursor or you will end with the RuntimeException!
        cursor.close();
    }
}

Answer 3

阿卡什·库里安·何塞的替代品

答案

Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), uri);

我总是使用

fun getBitmap(file: Uri, cr: ContentResolver): Bitmap?{
            var bitmap: Bitmap ?= null
            try {
                val inputStream = cr.openInputStream(file)
                bitmap = BitmapFactory.decodeStream(inputStream)
                // close stream
                try {
                    inputStream.close()
                } catch (e: IOException) {
                    e.printStackTrace()
                }
            }catch (e: FileNotFoundException){}
            return bitmap
        }

它适用于图库中的照片和相机中的照片。

更大的问题：毕加索无法显示图库中的图像

使用此方法打开图库：

private void openGallery(){
    if (Build.VERSION.SDK_INT <19){
        Intent intent = new Intent(); 
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        startActivityForResult(Intent.createChooser(intent, getResources().getString(R.string.select_picture)),GALLERY_INTENT_CALLED);
    } else {
        Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        intent.setType("image/*");
        startActivityForResult(intent, GALLERY_KITKAT_INTENT_CALLED);
    }
}

然后，您可以使用非洲ContentResolver.openInputStream读取将 Uri 转换为位图或设置图像ImageView.setImageUri(Uri)

Answer 4

如果要将所选图像显示到任何特定的图像视图。假设我们有 RC_PHOTO_PICKER = 1，那么这些代码行应该可以神奇地发挥作用

private void openPhotoPicker() {
    Intent photoPickerIntent = new Intent(Intent.ACTION_GET_CONTENT);
    photoPickerIntent.setType("image/*");
    photoPickerIntent.putExtra(Intent.EXTRA_LOCAL_ONLY, false);
    startActivityForResult(Intent.createChooser(photoPickerIntent,"Complete Action Using"), RC_PHOTO_PICKER);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == RC_PHOTO_PICKER && resultCode == RESULT_OK && data != null) {
        Uri pickedImage = data.getData();
        //set the selected image to ImageView
        mImageView.setImageURI(pickedImage);
    }
}

之后只需调用 openPhotoPicker（） 方法