android - 使用 mvvmcross 的 LinearLayout 背景颜色

Question

我有一个圆形的线性布局，想使用值转换器更改它的颜色。

下面是我的线性布局的样子

<LinearLayout
   android:orientation="vertical"
   android:id="@+id/linearLayoutDaysLeft"
   android:background="@drawable/RedBackground"
   local:MvxBind="BackgroundColor DateColor(EndDate)"/>

注意我已经将背景设置为@drawable/RedBackground

下面是我的@drawable/RedBackground.xml 文件的样子

<?xml version="1.0" encoding="utf-8" ?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
  <corners android:radius="10dip"/>
  <solid android:color="#D00E0D"/>
</shape>

下面是我的 DateColorValueConverter 代码

protected override Cirrious.CrossCore.UI.MvxColor Convert(object value, object parameter, System.Globalization.CultureInfo culture)
        {
            var date = (DateTime)value;
            int dayLeft;
            TimeSpan difference = date - DateTime.Today;
            dayLeft = (int)Math.Ceiling(difference.TotalDays);


            if (dayLeft < 0)
                return (new Cirrious.CrossCore.UI.MvxColor(208, 14, 13, 150));
            if (dayLeft >= 0 && dayLeft <= 1)
                return (new Cirrious.CrossCore.UI.MvxColor(255, 210, 0, 150));
            if (dayLeft > 1)
                return (new Cirrious.CrossCore.UI.MvxColor(93, 210, 85, 150));

            return (new Cirrious.CrossCore.UI.MvxColor(93, 210, 85, 150));
        }

请注意，我的 DateColor 按要求工作，但当它返回颜色时，它会移除圆形

请帮帮我

谢谢

阿曼

Answer 1

首先感谢Stuart指引了正确的方向

我已成功实现所需的可绘制背景更改

如果有人需要，我也想与其他人分享

下面是我自定义的 LinearLayout 绑定(bind)

public class ShapeBackgroundBinding : MvxAndroidTargetBinding
    {        
        private readonly LinearLayout _linearLayout;
        public ShapeBackgroundBinding(LinearLayout view) : base(view)
        {
            this._linearLayout = view;
        }
        protected override void SetValueImpl(object target, object value)
        {
            // to do logic
        }

        public override void SetValue(object value)
        {
            var date = (DateTime)value;
            int dayLeft;
            TimeSpan difference = date - DateTime.Today;
            dayLeft = (int)Math.Ceiling(difference.TotalDays);


            if (dayLeft < 0)
                _linearLayout.SetBackgroundResource(Resource.Drawable.RedBackground);
            else if (dayLeft >= 0 && dayLeft <= 1)
                _linearLayout.SetBackgroundResource(Resource.Drawable.YellowBackground);
            else if (dayLeft > 1)
                _linearLayout.SetBackgroundResource(Resource.Drawable.GreenBackground); 
            else
                _linearLayout.SetBackgroundResource(Resource.Drawable.GreenBackground);
        }
        public override Type TargetType
        {
            get { return typeof(DateTime); }
        }
        public override MvxBindingMode DefaultMode
        {
            get { return MvxBindingMode.OneTime; }
        }        
    }

下面是我如何在设置文件中注册自定义绑定(bind)

 protected override void FillTargetFactories(IMvxTargetBindingFactoryRegistry registry)
        {
            base.FillTargetFactories(registry);
            registry.RegisterFactory(new MvxCustomBindingFactory<LinearLayout>("ShapeBackground", (view) => new ShapeBackgroundBinding(view)));
        }

完成上述步骤后，简单的我们只需要像下面的代码 fragment 一样绑定(bind)线性布局控件

<LinearLayout
    android:orientation="vertical"
    android:id="@+id/linearLayoutTest"                    
    local:MvxBind="ShapeBackground EndDate">

就是这样......