C# 任何时候都只能打开一个ContentDialog

如果我多次按我的登录按钮，它会触发消息：“异步操作未正确启动。任何时候只能打开一个ContentDialog。”（延迟表示应用程序与服务器联系以查看用户是否有效所需的时间。）

如果我使用MessageDialog，一切正常，但我想使用ContentDialog提供的额外定制

链接没有帮助。下面的代码示例演示了如何使用它

XAML：

---

在处理单击时禁用该按钮

private async void Button_Click(object sender, RoutedEventArgs e)
{
    if (sender is Button button)
    {
        button.IsEnabled = false;
    }

    … handle button click

    if (sender is Button button2)
    {
        button2.IsEnabled = true;
    }
}

---

在打开下一个对话框之前，请尝试此操作

ContentDialogMaker.ActiveDialog?.Hide();
// Show new Dialog here.

---

通常，启动登录方法时，需要同时启用登录按钮以避免多次单击。您的解决方案也可用，直到显示上一个对话框，按钮才会工作

我还创建了新的

ContentDialogMaker

。有关更多信息，请参考以下内容

public static class ContentDialogMaker
{
    public static async void CreateContentDialog(ContentDialog Dialog, bool awaitPreviousDialog) { await CreateDialog(Dialog, awaitPreviousDialog); }
    public static async Task CreateContentDialogAsync(ContentDialog Dialog, bool awaitPreviousDialog) { await CreateDialog(Dialog, awaitPreviousDialog); }

    static async Task CreateDialog(ContentDialog Dialog, bool awaitPreviousDialog)
    {
        if (ActiveDialog != null)
        {
            if (awaitPreviousDialog)
            {
                ActiveDialog.Hide();
            }
            else
            {
                switch (Info.Status)
                {
                    case AsyncStatus.Started:
                        Info.Cancel();
                        break;
                    case AsyncStatus.Completed:
                        Info.Close();
                        break;
                    case AsyncStatus.Error:

                        break;
                    case AsyncStatus.Canceled:

                        break;
                }
            }
        }
        ActiveDialog = Dialog;
        ActiveDialog.Closing += ActiveDialog_Closing;
        Info = ActiveDialog.ShowAsync();
    }
    public static IAsyncInfo Info;
    private static void ActiveDialog_Closing(ContentDialog sender, ContentDialogClosingEventArgs args)
    {
        ActiveDialog = null;
    }

    public static ContentDialog ActiveDialog;
}

唯一的区别是

ActiveDialog

在

ActiveDialog\u Closing

事件处理程序方法中被清空。它还可以确保在显示之前的对话框后，该对话框将被清除。因此，只有一个

内容对话框将同时打开。
使用系统；
using System;
using System.Threading.Tasks;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;




namespace DuckTracker
{

public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
}

private async void Button_Click(object sender, RoutedEventArgs e)
{
bool canLogin = await CanLogin();

if (canLogin == false)
{
try
{
await AlertWithMessages("Fail", "Could not log in!", "ok");

}
catch (Exception ex)
{

var dialog = new Windows.UI.Popups.MessageDialog(ex.Message, "Error");
await dialog.ShowAsync();
}

}
}

public async Task AlertWithMessages(string title, string msg, string confirm)
{
ContentDialog dialog = new ContentDialog
{
Title = title,
Content = msg,
PrimaryButtonText = confirm
};


ContentDialogResult result = await dialog.ShowAsync();


}

public async Task<bool> CanLogin()
{
await Task.Delay(1000);

return false;
}
}
}

使用System.Threading.Tasks；
使用Windows.UI.Xaml；
使用Windows.UI.Xaml.Controls；
名称空间跟踪器
{
公共密封部分类主页面：第页
{
公共主页（）
{
this.InitializeComponent（）；
}
专用异步无效按钮\u单击（对象发送方，路由目标）
{
bool canLogin=wait canLogin（）；
if（canLogin==false）
{
尝试
{
使用消息等待警报（“失败”、“无法登录！”、“确定”）；
}
捕获（例外情况除外）
{
var dialog=newwindows.UI.Popups.MessageDialog（例如Message，“Error”）；
wait dialog.ShowAsync（）；
}
}
}
公共异步任务AlertWithMessages（字符串标题、字符串消息、字符串确认）
{
ContentDialog=新建ContentDialog
{
头衔，
内容=味精，
PrimaryButtonText=确认
};
ContentDialogResult=Wait dialog.ShowAsync（）；
}
公共异步任务CanLogin（）
{
等待任务。延迟（1000）；
返回false；
}
}
}
我以为这已经解决了问题，但还没有解决。我仍然得到相同的错误。你如何在这里附加单击事件，如PrimaryButtonClick？
private async void Button_Click(object sender, RoutedEventArgs e)
{
    if (sender is Button button)
    {
        button.IsEnabled = false;
    }

    … handle button click

    if (sender is Button button2)
    {
        button2.IsEnabled = true;
    }
}

ContentDialogMaker.ActiveDialog?.Hide();
// Show new Dialog here.

public static class ContentDialogMaker
{
    public static async void CreateContentDialog(ContentDialog Dialog, bool awaitPreviousDialog) { await CreateDialog(Dialog, awaitPreviousDialog); }
    public static async Task CreateContentDialogAsync(ContentDialog Dialog, bool awaitPreviousDialog) { await CreateDialog(Dialog, awaitPreviousDialog); }

    static async Task CreateDialog(ContentDialog Dialog, bool awaitPreviousDialog)
    {
        if (ActiveDialog != null)
        {
            if (awaitPreviousDialog)
            {
                ActiveDialog.Hide();
            }
            else
            {
                switch (Info.Status)
                {
                    case AsyncStatus.Started:
                        Info.Cancel();
                        break;
                    case AsyncStatus.Completed:
                        Info.Close();
                        break;
                    case AsyncStatus.Error:

                        break;
                    case AsyncStatus.Canceled:

                        break;
                }
            }
        }
        ActiveDialog = Dialog;
        ActiveDialog.Closing += ActiveDialog_Closing;
        Info = ActiveDialog.ShowAsync();
    }
    public static IAsyncInfo Info;
    private static void ActiveDialog_Closing(ContentDialog sender, ContentDialogClosingEventArgs args)
    {
        ActiveDialog = null;
    }

    public static ContentDialog ActiveDialog;
}

using System;
using System.Threading.Tasks;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;




namespace DuckTracker
{

public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
}

private async void Button_Click(object sender, RoutedEventArgs e)
{
bool canLogin = await CanLogin();

if (canLogin == false)
{
try
{
await AlertWithMessages("Fail", "Could not log in!", "ok");

}
catch (Exception ex)
{

var dialog = new Windows.UI.Popups.MessageDialog(ex.Message, "Error");
await dialog.ShowAsync();
}

}
}

public async Task AlertWithMessages(string title, string msg, string confirm)
{
ContentDialog dialog = new ContentDialog
{
Title = title,
Content = msg,
PrimaryButtonText = confirm
};


ContentDialogResult result = await dialog.ShowAsync();


}

public async Task<bool> CanLogin()
{
await Task.Delay(1000);

return false;
}
}
}