看不到进度条

Question

我正在使用自定义对话框 class 来显示图像，由于某种原因，在图像完全加载之前，布局内部的进度条不可见。我正在使用滑行，如果我调用 fullImageProgreesBar.setVisibility(View.VISIBLE); 我可以看到已加载图片上方的进度条。

我想在图片加载前显示进度条。

我的对话框class:

public class FullSizeImageDialog extends Dialog {
private ImageView imageView;
private ProgressBar fullImageProgreesBar;
private Context dialogContext;

public FullSizeImageDialog(@NonNull Context context) {
    super(context);
    setContentView(R.layout.full_size_image_dialog);
    dialogContext = context;
    imageView = findViewById(R.id.full_size_image);
    fullImageProgreesBar = findViewById(R.id.fullImageProgreesBar);
}

public void setImageFullSize(Uri imageUri) {
    Glide.with(dialogContext).load(imageUri)
            .listener(new RequestListener<Uri, GlideDrawable>() {
                @Override
                public boolean onException(Exception e, Uri model, Target<GlideDrawable> target, boolean isFirstResource) {
                    fullImageProgreesBar.setVisibility(View.INVISIBLE);
                    Toast.makeText(dialogContext, "No image available", Toast.LENGTH_SHORT).show();
                    return false;
                }

                @Override
                public boolean onResourceReady(GlideDrawable resource, Uri model, Target<GlideDrawable> target, boolean isFromMemoryCache, boolean isFirstResource) {
                    fullImageProgreesBar.setVisibility(View.INVISIBLE);
                    return false;
                }
            }).into(imageView);
    }
}

我的对话框布局文件：

<?xml version="1.0" encoding="utf-8"?>
  <android.support.constraint.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent">


<ProgressBar
    android:id="@+id/fullImageProgreesBar"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:elevation="6dp"
    android:layout_marginTop="8dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="@+id/full_size_image" />


<ImageView
    android:id="@+id/full_size_image"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginStart="8dp"
    android:layout_marginTop="8dp"
    android:layout_marginEnd="8dp"
    android:layout_marginBottom="8dp"
    android:background="@drawable/new_question"
    android:fitsSystemWindows="true"
    android:scaleType="fitXY"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />


 </android.support.constraint.ConstraintLayout>

没有为我解决这个问题的事情：

从 XML

ProgressBar

更改ProgressBar尺寸
更改ConstaintLayout中的顺序或元素（ProgressBar在XML文件和编辑器中的ImageView之上和之下）

如有任何帮助，我们将不胜感激。

Answer 1

您似乎忘记在 onResourceReady 中加载图像时将进度条的可见性更改为可见。改变这个

fullImageProgreesBar.setVisibility(View.INVISIBLE);

至此

fullImageProgreesBar.setVisibility(View.VISIBLE);

看不到进度条

can't see progress bar

android

android-layout

progress-bar

android-dialog