ImageView将可见性从“消失”更改为“可见”后不显示图像

Question

我有这个ImageView:

<ScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/black"
android:id="@+id/formSuggestionScroll">
<LinearLayout 
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    tools:context=".SuggestQuestionActivity" 
    android:orientation="vertical"
    android:scrollbars="vertical"
    android:background="@android:color/black">
  <Button
    android:id="@+id/btnOpenGallery"
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:text="@string/suggest_btnOpenGallery"
    android:onClick="btnOpenGallery_click"
    android:textColor="@android:color/white"
    android:paddingTop="@dimen/buttons_paddingTop"/>
  <ImageView
      android:id="@+id/selectedPicContainer"
      android:layout_width="@dimen/imagen_dimen_width"
      android:layout_height="@dimen/imagen_dimen_height"
      android:layout_marginTop="@dimen/image_padding"
      android:adjustViewBounds="true" 
      android:layout_gravity="center_horizontal"
      android:visibility="gone"/>
  <Button
    android:id="@+id/btnSend"
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:text="@string/suggest_send"
    android:onClick="btnSend_click"
    android:textColor="@android:color/white"
    android:paddingTop="@dimen/buttons_paddingTop"/>
</LinearLayout>

我想让它在用户选择图片库后可见：

public void onActivityResult(int requestCode, int resultCode, Intent data)
{
    switch(requestCode){
        case SELECT_PHOTO:
            if(resultCode == RESULT_OK){
                ImageView view = (ImageView) findViewById(R.id.selectedPicContainer);

                imageUri = data.getData();
                Bitmap galleryPic = scaleBitmap(getPathFromUri(imageUri), view.getHeight());
                if(galleryPic != null){
                    view.setImageBitmap(galleryPic);
                    view.setVisibility(View.VISIBLE);
                }else{
                    Toast toast = Toast.makeText(this, "selection failed", Toast.LENGTH_LONG);
                    toast.show();
                }
            }
            break;
    }
}

scaleBitmap函数代码：

private Bitmap scaleBitmap(String imagePath, int maxDimension) {
    Bitmap scaledBitmap;
    BitmapFactory.Options op = new BitmapFactory.Options();
    op.inJustDecodeBounds = true; 
    scaledBitmap = BitmapFactory.decodeFile(imagePath,op);
    if(maxDimension < op.outHeight || maxDimension < op.outWidth){
        op.inSampleSize = Math.round(Math.max((float) op.outHeight / (float) maxDimension,
                                              (float)op.outWidth / (float) maxDimension));
    }
    op.inJustDecodeBounds = false;
    scaledBitmap = BitmapFactory.decodeFile(imagePath,op);
    return scaledBitmap;
}

问题是ImageView显示的是彩色正方形，而不是图片。颜色取决于选择的图像。所以渲染可能有问题，但我对此的了解很少。

如果我将可见性设置为不可见而不是消失，问题就会消失。

希望有人能帮忙。感谢

Answer 1

会因为view.getHeight()是GONE而使其为0吗？那么scaleBitmap(getPathFromUri(imageUri), view.getHeight())可能将其缩放为1像素？

Answer 2

u也可以显示默认图像，而不是使视图不可见