如何创建一个对话框来提示用户在 WPF 中选择是/否选项

How to Create a DialogBox to prompt the user for Yes/No option in WPF

提问by Shamim Hafiz

I know how to do this on Windows Form App, but I couldn't find anyway of doing so on a WPF App. How would I present the user a blocking DialogBox with Yes/No option and get/process the response from the user?

我知道如何在 Windows 窗体应用程序上执行此操作，但无论如何我都找不到在 WPF 应用程序上执行此操作的方法。我将如何向用户显示一个带有 Yes/No 选项的阻塞 DialogBox 并获取/处理来自用户的响应？

回答by rid

Here's an example:

这是一个例子：

string sMessageBoxText = "Do you want to continue?";
string sCaption = "My Test Application";

MessageBoxButton btnMessageBox = MessageBoxButton.YesNoCancel;
MessageBoxImage icnMessageBox = MessageBoxImage.Warning;

MessageBoxResult rsltMessageBox = MessageBox.Show(sMessageBoxText, sCaption, btnMessageBox, icnMessageBox);

switch (rsltMessageBox)
{
    case MessageBoxResult.Yes:
    /* ... */
    break;

    case MessageBoxResult.No:
    /* ... */
    break;

    case MessageBoxResult.Cancel:
    /* ... */
    break;
}

回答by Frinavale

Please note that while Radu's answer works, you cannot apply WPF styles to the MessageBox.

请注意，虽然 Radu 的答案有效，但您不能将 WPF 样式应用于 MessageBox。

I took a different approach to this problem.

我对这个问题采取了不同的方法。

I created a class to serve as a View Model for my message window and I created a style for how I wanted my window to appear. Later in code I instantiated a new Window, set it's DataContext to an instance of my View Model, and set the Window's Style property to the style I created for the window.

我创建了一个类作为我的消息窗口的视图模型，并创建了一个样式来显示我希望我的窗口的显示方式。稍后在代码中，我实例化了一个新窗口，将它的 DataContext 设置为我的视图模型的一个实例，并将 Window 的 Style 属性设置为我为该窗口创建的样式。

I know it sounds a bit overkill, and I'm not sure how other people go about solving this same issue... but my solution is quite flexible and I'm starting to really like it.

我知道这听起来有点矫枉过正，我不确定其他人如何解决同样的问题……但我的解决方案非常灵活，我开始非常喜欢它。

For example, here is Dialog View Model:

例如，这是对话框视图模型：

Public Class MyDialogViewModel
  Public Event Closed()

  Public Property Message As String

  Public Property Cancel As MyNamespace.RelayCommand
  Public Property Close As MyNamespace.RelayCommand
  Public Property WasCancelled As Boolean

  Public Sub New()
    WasCancelled = True
    Cancel = New MyNamespace.RelayCommand(AddressOf CancelClicked)
    Close = New MyNamespace.RelayCommand(AddressOf CloseClicked)
  End Sub

  Private Sub CancelClicked()
    RaiseEvent Closed()
  End Sub
  Private Sub CloseClicked()
    WasCancelled = False
    RaiseEvent Closed()
  End Sub
End Class

Here is my style for a basic "message" window:

这是我的基本“消息”窗口样式：

    <Style x:Key="myMessageStyle" TargetType="{x:Type myNameSpace:CustomDialogWindow}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate>
                    <ControlTemplate.Resources>
                        <Style TargetType="{x:Type Button}" BasedOn="{StaticResource {x:Type Button}}">
                            <Setter Property="Width" Value="100"/>
                            <Setter Property="Height" Value="25"/>
                        </Style>
                    </ControlTemplate.Resources>
                    <Border >
                        <DockPanel Margin="10,10,0,10">
                            <TextBlock Text="{Binding Message}" Width="Auto" TextWrapping="WrapWithOverflow" DockPanel.Dock="Top" 
                                       Margin="10"
                                       Foreground="{StaticResource MyMessageBoxForegroundColor}"/>
                            <DockPanel Margin="5,0,0,0" DockPanel.Dock="Bottom">
                                <Button Content="Ok" Command="{Binding Close}" ></Button>
                                <Button Content="Cancel" Command="{Binding Cancel}"  HorizontalAlignment="Stretch"></Button>
                            </DockPanel>
                        </DockPanel>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

My CustomDialogWindow is simply a window with nothing in it:

我的 CustomDialogWindow 只是一个没有任何内容的窗口：

(XAML)

(XAML)

<Window x:Class="CustomDialogWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="CustomDialogWindow"
        SizeToContent="WidthAndHeight">

</Window>

And in the CustomDialogWindow I have the following code so that the window closes when the user clicks cancel or ok:

在 CustomDialogWindow 中，我有以下代码，以便在用户单击取消或确定时关闭窗口：

Public Class CustomDialogWindow 

    Private Sub CustomDialogWindow_DataContextChanged(ByVal sender As Object, ByVal e As System.Windows.DependencyPropertyChangedEventArgs) Handles Me.DataContextChanged
        Dim dContext As MyDialogViewModel= TryCast(DataContext, MyDialogViewModel)
        If dContext IsNot Nothing Then
            AddHandler DirectCast(DataContext, MyDialogViewModel).CloseWindow, AddressOf CloseWindow
        End If
    End Sub
    Private Sub CloseWindow()
        Me.Close()
    End Sub
End Class

Now when I need to use the window I just instantiate a new CustomDialogWindow, set it's DataContext to a new instance of the DialogViewModel class, and set it's style to the "myMessageStyle":

现在，当我需要使用该窗口时，我只需实例化一个新的 CustomDialogWindow，将其 DataContext 设置为 DialogViewModel 类的新实例，并将其样式设置为“myMessageStyle”：

Dim cdw As New CustomDialogWindow
Dim dvm As New DialogViewModel
dvm.Message = "Hello World!"
cdw.DataContext = dvm
cdw.ShowDialog()

If dvm.WasCancelled = False Then 
  '....'
End If

The reason why I like this approach is because I inherit from the MyDialogViewModel and provide more properties so that, for instance, I can display a bunch of options for the user to choose from. I just supply custom styles for each type of window I want to display (making sure to bind the appropriate properties). Like I said, it's very flexible and pretty simple to implement.

我喜欢这种方法的原因是因为我从 MyDialogViewModel 继承并提供了更多属性，例如，我可以显示一堆选项供用户选择。我只是为我想要显示的每种类型的窗口提供自定义样式（确保绑定适当的属性）。就像我说的，它非常灵活且易于实现。

Cheers!

干杯!

-Frinny

-弗林尼