設置前景以編程方式查看

Question

我已經以編程方式設置背景。現在我必須為我的 LinearLayout 添加漣漪效果，所以我不僅需要設置背景，還需要設置前景

代碼：

        public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
        {
            var vh = holder as StaffViewHolder;

            vh.Layout.SetBackgroundColor(position % 2 == 0 ? Color.ParseColor("#ffffff") : Color.ParseColor("#f5f5f5"));
            //vh.Layout.Foreground = "?attr/selectableItemBackground";
            vh.StaffTv.Text = items[position].Name;
        }

        class StaffViewHolder : RecyclerView.ViewHolder
        {
            public TextView StaffTv { get; private set; }
            public LinearLayout Layout { get; private set; }

        public StaffViewHolder(View view) : base(view)
        {
            StaffTv = view.FindViewById<TextView>(Resource.Id.StaffItemLayout_textTv);
            Layout = view.FindViewById<LinearLayout>(Resource.Id.StaffItemLayout_layout);
        }
    }

Answer 1

您可以從該屬性資源中獲取 drawable，如下所示：

public Drawable GetDrawableFromAttrRes(int attrRes, Context context)
{
    TypedArray a = context.ObtainStyledAttributes(new int[] { attrRes });
    try
    {
        return a.GetDrawable(0);
    }
    finally
    {
        a.Recycle();
    }
}

然后您將使用如下：

vh.Layout.Foreground = GetDrawableFromAttrRes(Resource.Attribute.selectableItemBackground, context);

Answer 2

如果你有前景漣漪xml：

例如ripple_foreground.xml （在Resources/drawable-v21 中）：

<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
     android:color="#f5f5f5">
</ripple>

你可以這樣設置：

public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
    {
        var vh = holder as StaffViewHolder;
        vh.Layout.SetBackgroundColor(position % 2 == 0 ? Color.ParseColor("#ffffff") : Color.ParseColor("#f5f5f5"));
        vh.Layout.Foreground = vh.ItemView.Context.GetDrawable(Resource.Drawable.ripple_foreground);
        vh.StaffTv.Text = items[position].Name;
    }

並且需要設置 LinearLayout 屬性

android:clickable="true"

效果是這樣的：