xamarin - 如何使用自定义渲染器在 Xamarin Forms 中制作带圆角的进度条

Question

我想在 Xamarin 表单中显示带有圆角的进度条。我可以使用自定义渲染器在 iOS 中完成此操作:

class CustomProgressBarRenderer: ProgressBarRenderer
{
    protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.ProgressBar> e)
    {
        base.OnElementChanged(e);
        Control.ProgressTintColor = Color.FromRgb(255, 201, 74).ToUIColor();
    }

    public override void LayoutSubviews()
    {
        base.LayoutSubviews();
        var X = 1.0f;
        var Y = 7.0f;
        CGAffineTransform transform = CGAffineTransform.MakeScale(X, Y);
        this.Transform = transform;
        this.ClipsToBounds = true;
        this.Layer.MasksToBounds = true;
        this.Layer.CornerRadius = 5; // This is for rounded corners.
    }
}

如何使用自定义渲染器在 Android 中实现相同的效果。这就是我想要的进度条(圆角)的外观。

Answer 1

How to make a progress bar with rounded corners in Xamarin forms

您可以在 Android ProgressBar 上添加一个 Drawable 来实现此功能。

设置 ProgressBar 、Drawable\bar_color.xml 的样式:

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <!--set progressbar backgound style-->
    <item
        android:id="@android:id/background"
        android:drawable="@drawable/progress_bar_background" />

    <!--set progressbar schedule style-->
    <item android:id="@android:id/progress">
        <scale
            android:drawable="@drawable/shape_progressbar_progress"
            android:scaleWidth="100%" />
    </item>

</layer-list>

Drawable\progress_bar_background.xml:

<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <corners android:radius="20dp" />
    <solid android:color="#FFCBC2C2" />
</shape>

Drawable\shape_progressbar_progress.xml:

<shape xmlns:android="http://schemas.android.com/apk/res/android">
   <corners android:radius="20dp" />
   <solid android:color="#3F8CC4" />
   <stroke
       android:width="0dp"
       android:color="#FFFFFF"></stroke>
</shape>

在您的CustomProgressBarRenderer中使用它:

public class CustomProgressBarRenderer : ProgressBarRenderer
{
    protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.ProgressBar> e)
    {
        base.OnElementChanged(e);

        if(Control != null)
        {
            var progressBar = Control as Android.Widget.ProgressBar;
            //below is now deprecated
            //var draw = Resources.GetDrawable(Resource.Drawable.bar_color);
            var draw = Context.GetDrawable(Resource.Drawable.bar_color);
            progressBar.ProgressDrawable = draw;
        }
    }
}

效果: