xamarin UWP平台下 HUD 自定义弹窗

在我的上一篇博客中我写了一个在xamarin的UWP平台下的自定义弹窗控件。在上篇文章中介绍了一种弹窗的写法，但在实际应用中发现了该方法的不足：

1、当弹窗出现后，我们拖动整个窗口大小的时候，弹窗的窗口大小没有随着主窗口大小变化。

2、当弹窗出现时，在我们的主窗口上的后退按钮并没有被弹窗遮罩住，这导致了在弹窗的时候窗口还能返回。

为解决上述问题，我们需更改原来的方式，方法如下：

1、定义一个uwp平台的用户控件

xaml文件代码：

 <UserControl
     x:Class="Test.UWP.ExtendControls.UWPHUD"
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:local="using:Test.UWP.ExtendControls"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     mc:Ignorable="d"
     d:DesignHeight=""
     d:DesignWidth="">

     <Grid Name="mask_grid" Background="{ThemeResource TKHUDColorBrush}" >
         <Grid Grid.Row="">
             <Border Background="Black" CornerRadius="" HorizontalAlignment="Center" VerticalAlignment="Center">
                 <TextBlock Margin="" Name="msg_Txt" Foreground="White" Text="..." MinWidth="" ></TextBlock>
             </Border>
         </Grid>

     </Grid>
 </UserControl>

UWPHUD.xaml

xaml.cs文件代码：

 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices.WindowsRuntime;
 using Windows.Foundation;
 using Windows.Foundation.Collections;
 using Windows.UI.Core;
 using Windows.UI.ViewManagement;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
 using Windows.UI.Xaml.Controls.Primitives;
 using Windows.UI.Xaml.Data;
 using Windows.UI.Xaml.Input;
 using Windows.UI.Xaml.Media;
 using Windows.UI.Xaml.Navigation;

 // The User Control item template is documented at http://go.microsoft.com/fwlink/?LinkId=234236

 namespace Test.UWP.ExtendControls
 {
     public sealed partial class UWPHUD : UserControl
     {

         Popup popup;
         public UWPHUD()
         {
             this.InitializeComponent();
             SystemNavigationManager.GetForCurrentView().BackRequested += UWPHUD_BackRequested;
         }
         public UWPHUD(string message)
         {
             this.InitializeComponent();
             SystemNavigationManager.GetForCurrentView().BackRequested += UWPHUD_BackRequested;
             msg_Txt.Text = message;
         }

         private void UWPHUD_BackRequested(object sender, BackRequestedEventArgs e)
         {
             HUDClose();
         }

         public void Show()
         {
             //var appView = ApplicationView.GetForCurrentView();
             popup = new Popup();
             popup.Child = this;
             var bounds = Window.Current.Bounds;
             this.Width = bounds.Width;
             this.Height = bounds.Height;
             popup.IsOpen = true;
         }
         public void HUDClose()
         {
             if (popup.IsOpen)
             {
                 popup.IsOpen = false;
             }
         }

     }
 }

UWPHUD.xaml.cs

同时在原来的基础代码上调用现在定义好的uwp用户控件，代码如下：

 using Mixin.Dependencies;
 using Mixin.UWP.ExtendControls;
 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using Windows.UI;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
 using Windows.UI.Xaml.Controls.Primitives;
 using Windows.UI.Xaml.Media;
 using Xamarin.Forms;

 [assembly: Dependency(typeof(Mixin.UWP.Dependencies.HUD))]
 namespace Test.UWP.Dependencies
 {
     public class HUD : IHUD
     {
         private UWPHUD uwpHUD = null;
         public HUD() { }

         public void Show(string msg)
         {
             ShowProgress(msg);
         }
         public void ShowSuccess(string msg)
         {
             ShowProgress(msg, );
         }
         public void ShowError(string msg)
         {
             ShowProgress(msg, );
         }
         public void ShowErrorLong(string msg)
         {
             ShowProgress(msg, );
         }

         public void ShowProgress(string msg, int second = )
         {
             uwpHUD = new UWPHUD(msg);
             uwpHUD.Show();

             if (second > )
             {
                 Task.Delay(second)
                 .ContinueWith(t =>
                 {
                     Device.BeginInvokeOnMainThread(() =>
                     {
                         uwpHUD.HUDClose();
                     });
                 }
               );
             }
             else
             {
                 Task.Delay()
                 .ContinueWith(t =>
                 {
                     Device.BeginInvokeOnMainThread(() =>
                     {
                         uwpHUD.HUDClose();
                     });
                 }
               );
             }
         }
         public void Dismiss()
         {
             Device.BeginInvokeOnMainThread(() =>
             {
                 uwpHUD.HUDClose();
             });
         }
     }
 }

HUD.cs

经如上方式可解决弹窗的两个问题。