设置ImageView的图像资源不可见或消失时，没有显示图像

Question

我有一个ImageView，它已初始化并以编程方式添加到从LinearLayout派生的自定义视图中。自定义视图在XML布局中引用。

图像资源是使用SetImageResource设置的，其容器视图状态最初是不可见的（我也尝试过使用消失的视图状态）。

事件发生后，容器的可见性在主UI线程上设置为可见视图状态。

期望

将容器的可见性设置为“可见”后，我希望能正确显示图像，但是我看不到图像。

实际

如果将容器的初始视图状态设置为不可见，那么当可见性切换为可见时，我会看到ImageView占据了预期的宽度和高度（使用布局边界），但是没有可见的图像。

如果我将容器的初始视图状态设置为走了，那么当可见性切换为可见时，我看不到ImageView占用了预期的宽度和高度（使用布局边界）并且没有可见的图像。

将容器LinearLayout的可见性设置为可见时，为什么没有出现ImageView图像？

下面是我的自定义类（图像下方显示了两个标题）：

using System;
using System.Linq.Expressions;
using Android.Content;
using Android.Content.Res;
using Android.Graphics;
using Android.Graphics.Drawables;
using Android.Runtime;
using Android.Support.V4.Content;
using Android.Support.V7.Widget;
using Android.Util;
using Android.Views;
using Android.Widget;
using Orientation = Android.Widget.Orientation;

namespace ShrimpleSearch.Components
{
    public class CaptionImageView : LinearLayout
    {
        private static TypedArray ReadStyleAttributes(
            Context context
            , IAttributeSet attributeSet
        ) => context.ObtainStyledAttributes(
            attributeSet
            , Resource.Styleable.CaptionImageView
            , 0
            , 0
        );

        private static int GetImageResource(
            TypedArray styleAttributes
        ) => styleAttributes.GetResourceId(
            Resource.Styleable.CaptionImageView_drawableSrc
            , 0
        );

        private static float GetDrawableMarginBottom(
            TypedArray styleAttributes
        ) => styleAttributes.GetDimensionPixelSize(
            Resource.Styleable.CaptionImageView_drawableMarginBottom
            , 0
        );

        private static Color GetPrimaryTextColor(
            TypedArray styleAttributes
        ) => styleAttributes.GetColor(
            Resource.Styleable.CaptionImageView_primaryTextColor
            , Color.Black
        );

        private static string GetPrimaryText(
            TypedArray styleAttributes
        ) => styleAttributes.GetString(Resource.Styleable.CaptionImageView_primaryText);

        private static Typeface GetPrimaryFontFamily(
            TypedArray styleAttributes
        ) => styleAttributes.GetFont(Resource.Styleable.CaptionImageView_primaryTextFontFamily);

        private static float GetPrimaryLetterSpacing(
            TypedArray styleAttributes
        ) => styleAttributes.GetFloat(
            Resource.Styleable.CaptionImageView_primaryLetterSpacing
            , 0f
        );

        private static float GetPrimaryTextSize(
            TypedArray styleAttributes
        ) => styleAttributes.GetDimensionPixelSize(
            Resource.Styleable.CaptionImageView_primaryTextSize
            , 0
        );

        private static float GetPrimaryTextBottomMargin(
            TypedArray styleAttributes
        ) => styleAttributes.GetDimensionPixelSize(
            Resource.Styleable.CaptionImageView_primaryTextBottomMargin
            , 0
        );

        private static Color GetSecondaryTextColor(
            TypedArray styleAttributes
        ) => styleAttributes.GetColor(
            Resource.Styleable.CaptionImageView_secondaryTextColor
            , Color.Black
        );

        private static float GetSecondaryLetterSpacing(
            TypedArray styleAttributes
        ) => styleAttributes.GetFloat(
            Resource.Styleable.CaptionImageView_secondaryLetterSpacing
            , 0f
        );

        private static float GetSecondaryTextSize(
            TypedArray styleAttributes
        ) => styleAttributes.GetDimensionPixelSize(
            Resource.Styleable.CaptionImageView_secondaryTextSize
            , 0
        );

        private static float GetSecondaryTextHorizontalPadding(
            TypedArray styleAttributes
        ) => styleAttributes.GetDimensionPixelSize(
            Resource.Styleable.CaptionImageView_secondaryTextHorizontalPadding
            , 0
        );

        private static Typeface GetSecondaryFontFamily(
            TypedArray styleAttributes
        ) => styleAttributes.GetFont(Resource.Styleable.CaptionImageView_secondaryTextFontFamily);

        private static string GetSecondaryText(
            TypedArray styleAttributes
        ) => styleAttributes.GetString(Resource.Styleable.CaptionImageView_secondaryText);

        private static float GetPrimaryTextLineSpacing(
            TypedArray styleAttributes
        ) => styleAttributes.GetFloat(Resource.Styleable.CaptionImageView_primaryTextLineSpacing, 1f);

        private static float GetSecondaryTextLineSpacing(
            TypedArray styleAttributes
        ) => styleAttributes.GetFloat(Resource.Styleable.CaptionImageView_secondaryTextLineSpacing, 1f);

        private static AppCompatImageView CreateImageView(
            Context context
            , TypedArray styleAttributes
            , IAttributeSet attributeSet
        )
        {
            var layoutParameters = new LayoutParams(
                ViewGroup.LayoutParams.MatchParent
                , ViewGroup.LayoutParams.WrapContent
            ) {Weight = 1};

            layoutParameters.SetMargins(
                0
                , 0
                , 0
                , (int) GetDrawableMarginBottom(styleAttributes)
            );

            var imageView = new AppCompatImageView(context, attributeSet)
            {
                Id = GenerateViewId(),
                LayoutParameters = layoutParameters
            };

            imageView.SetImageResource(GetImageResource(styleAttributes));

            return imageView;
        }

        private static AppCompatTextView CreatePrimaryCaptionTextView(Context context, TypedArray styleAttributes)
        {
            var layoutParams = new LayoutParams(
                ViewGroup.LayoutParams.MatchParent
                , ViewGroup.LayoutParams.WrapContent
            ) {Weight = 0};

            layoutParams.SetMargins(
                0
                , 0
                , 0
                , (int) GetPrimaryTextBottomMargin(styleAttributes)
            );

            var textView = new LetterSpacingTextView(context)
            {
                Id = GenerateViewId(),
                Text = GetPrimaryText(styleAttributes),
                LetterSpacing = GetPrimaryLetterSpacing(styleAttributes),
                TextAlignment = TextAlignment.Center,
                Typeface = GetPrimaryFontFamily(styleAttributes),
                LayoutParameters = layoutParams
            };

            textView.SetLineSpacing(0, GetPrimaryTextLineSpacing(styleAttributes));
            textView.SetTextSize(ComplexUnitType.Px, GetPrimaryTextSize(styleAttributes));
            textView.SetTextColor(GetPrimaryTextColor(styleAttributes));

            return textView;
        }

        private static AppCompatTextView CreateSecondaryCaptionTextView(Context context, TypedArray styleAttributes)
        {
            var layoutParams = new LayoutParams(
                ViewGroup.LayoutParams.MatchParent
                , ViewGroup.LayoutParams.WrapContent
            ) {Weight = 0};

            var horizontalPadding = (int) GetSecondaryTextHorizontalPadding(styleAttributes);

            layoutParams.SetMargins(
                horizontalPadding
                , 0
                , horizontalPadding
                , 0
            );

            var textView = new LetterSpacingTextView(context)
            {
                Id = GenerateViewId(),
                Text = GetSecondaryText(styleAttributes),
                LetterSpacing = GetSecondaryLetterSpacing(styleAttributes),
                TextAlignment = TextAlignment.Center,
                Typeface = GetSecondaryFontFamily(styleAttributes),
                LayoutParameters = layoutParams
            };

            textView.SetLineSpacing(0, GetSecondaryTextLineSpacing(styleAttributes));
            textView.SetTextSize(ComplexUnitType.Px, GetSecondaryTextSize(styleAttributes));
            textView.SetTextColor(GetSecondaryTextColor(styleAttributes));

            return textView;
        }

        protected CaptionImageView(
            IntPtr javaReference
            , JniHandleOwnership transfer
        ) : base(javaReference, transfer) => Expression.Empty();

        public CaptionImageView(Context context) : base(context) => Expression.Empty();

        public CaptionImageView(
            Context context
            , IAttributeSet attrs
        ) : base(context, attrs) => Init(context, attrs);

        public CaptionImageView(
            Context context
            , IAttributeSet attrs
            , int defStyleAttr
        ) : base(context, attrs,
            defStyleAttr) => Init(context, attrs);

        public CaptionImageView(
            Context context
            , IAttributeSet attrs
            , int defStyleAttr
            , int defStyleRes
        ) : base(context, attrs, defStyleAttr, defStyleRes) => Init(context, attrs);

        private void Init(Context context, IAttributeSet attrs)
        {
            var styleAttributes = ReadStyleAttributes(context, attrs);

            var imageView = CreateImageView(context, styleAttributes, attrs);
            var primaryCaptionTextView = CreatePrimaryCaptionTextView(context, styleAttributes);
            var secondaryCaptionTextView = CreateSecondaryCaptionTextView(context, styleAttributes);

            Orientation = Orientation.Vertical;

            AddView(imageView);
            AddView(primaryCaptionTextView);
            AddView(secondaryCaptionTextView);
        }
    }
}