# 异步业务逻辑
在某些业务场景中，用户点击某个按钮后需要以阻塞形式执行一段业务逻辑，等待业务逻辑执行完毕后继续执行弹窗后续逻辑。在这个示例中，我们通过 StandardButtons 属性为弹窗设定了确定和取消两个按钮，当用户点击确定的时候需要同步阻塞执行一段业务逻辑。
下面这个示例中，我们通过 ButtonClicked 属性绑定一个事件（HandleAsyncDialogButtonClicked），这个事件会执行具体的业务逻辑（业务逻辑代码位于code-behind文件中）。
一些嗅觉灵敏格局大的开发者可能现在已经想到了一个问题：在本示例中， ButtonClicked 绑定的事件是响应是哪个按钮呢？是确定按钮，还是取消按钮呢？其实是都相应，本质上是在 HandleAsyncDialogButtonClicked 业务逻辑代码中判断来源按钮，针对不同按钮做不同逻辑。
axaml文件：
<StackPanel Orientation="Horizontal" Spacing="10">
<Panel>
<atom:Button ButtonType="Primary" Name="AsyncDialogOpenModalButton">
Open Modal with async logic
</atom:Button>
<atom:Dialog PlacementTarget="AsyncDialogOpenModalButton"
IsOpen="{Binding IsAsyncDialogOpened, Mode=TwoWay}"
Title="Asynchronously close Modal"
IsModal="True"
IsDragMovable="True"
IsLightDismissEnabled="True"
IsResizable="False"
IsMaximizable="False"
StandardButtons="Ok, Cancel"
HorizontalStartupLocation="Center"
VerticalStartupLocation="Center"
DefaultStandardButton="Ok"
ButtonClicked="HandleAsyncDialogButtonClicked"
MinWidth="400">
<StackPanel>
<TextBlock>Content of the modal</TextBlock>
</StackPanel>
</atom:Dialog>
</Panel>
</StackPanel>
code-behind文件：
using System.Reactive.Disposables;
using AtomUI.Controls;
using AtomUIGallery.ShowCases.ViewModels;
using Avalonia.Interactivity;
using Avalonia.ReactiveUI;
using Avalonia.Threading;
using ReactiveUI;
namespace AtomUIGallery.ShowCases.Views;
public partial class ModalShowCase : ReactiveUserControl<ModalViewModel>
{
public ModalShowCase()
{
this.WhenActivated(disposables =>
{
BasicOpenModalButton.Click += HandleBasicModalButtonClick;
BasicWindowOpenModalButton.Click += HandleBasicWindowModalButtonClick;
ConfirmMsgBoxBtn.Click += HandleConfirmMsgBoxBtnClick;
InformationMsgBoxBtn.Click += HandleInformationMsgBoxBtnClick;
SuccessMsgBoxBtn.Click += HandleSuccessMsgBoxBtnClick;
ErrorMsgBoxBtn.Click += HandleErrorMsgBoxBtnClick;
WarningMsgBoxBtn.Click += HandleWarningMsgBoxBtnClick;
StyleCaseHostTypeSwitch.IsCheckedChanged += HandleStyleCaseHostTypeSwitchChanged;
LoadingDialogOpenModalButton.Click += HandleLoadingDialogOpenModalButtonClick;
AsyncDialogOpenModalButton.Click += HandleAsyncDialogOpenModalButtonClick;
CustomFooterDialogOpenButton.Click += HandleCustomFooterDialogOpenButtonClick;
CustomFooterMsgBoxOpenButton.Click += HandleCustomFooterMsgBoxOpenButtonClick;
DraggableDialogOpenButton.Click += HandleDraggableMsgBoxOpenButtonClick;
DelayedCloseMsgBoxOpenButton.Click += HandleDelayedCloseMsgBoxOpenButtonClick;
ConfigureButtonsDialogOpenButton.Click += HandleConfigureButtonsDialogButtonClick;
disposables.Add(Disposable.Create(() => BasicOpenModalButton.Click -= HandleBasicModalButtonClick));
disposables.Add(Disposable.Create(() => BasicWindowOpenModalButton.Click -= HandleBasicWindowModalButtonClick));
disposables.Add(Disposable.Create(() => ConfirmMsgBoxBtn.Click -= HandleConfirmMsgBoxBtnClick));
disposables.Add(Disposable.Create(() => InformationMsgBoxBtn.Click -= HandleInformationMsgBoxBtnClick));
disposables.Add(Disposable.Create(() => SuccessMsgBoxBtn.Click -= HandleSuccessMsgBoxBtnClick));
disposables.Add(Disposable.Create(() => ErrorMsgBoxBtn.Click -= HandleErrorMsgBoxBtnClick));
disposables.Add(Disposable.Create(() => WarningMsgBoxBtn.Click -= HandleWarningMsgBoxBtnClick));
disposables.Add(Disposable.Create(() => StyleCaseHostTypeSwitch.IsCheckedChanged -= HandleStyleCaseHostTypeSwitchChanged));
disposables.Add(Disposable.Create(() => LoadingDialogOpenModalButton.Click -= HandleLoadingDialogOpenModalButtonClick));
disposables.Add(Disposable.Create(() => CustomFooterDialogOpenButton.Click -= HandleCustomFooterDialogOpenButtonClick));
disposables.Add(Disposable.Create(() => CustomFooterMsgBoxOpenButton.Click -= HandleCustomFooterMsgBoxOpenButtonClick));
disposables.Add(Disposable.Create(() => DraggableDialogOpenButton.Click -= HandleDraggableMsgBoxOpenButtonClick));
disposables.Add(Disposable.Create(() => DelayedCloseMsgBoxOpenButton.Click -= HandleDelayedCloseMsgBoxOpenButtonClick));
disposables.Add(Disposable.Create(() => ConfigureButtonsDialogOpenButton.Click -= HandleConfigureButtonsDialogButtonClick));
ConfigureButtonPropertiesDialog.ButtonsConfigure = ConfigureButtonProperties;
if (DataContext is ModalViewModel viewModel)
{
viewModel.MessageBoxStyleCaseHostType = DialogHostType.Overlay;
viewModel.CountdownSeconds = 5;
}
});
InitializeComponent();
}
private void HandleBasicModalButtonClick(object? sender, RoutedEventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsBasicModalOpened = true;
}
}
private void HandleBasicWindowModalButtonClick(object? sender, RoutedEventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsBasicWindowModalOpened = true;
}
}
private void HandleConfirmMsgBoxBtnClick(object? sender, RoutedEventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsConfirmMsgBoxOpened = true;
}
}
private void HandleInformationMsgBoxBtnClick(object? sender, RoutedEventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsInformationMsgBoxOpened = true;
}
}
private void HandleSuccessMsgBoxBtnClick(object? sender, RoutedEventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsSuccessMsgBoxOpened = true;
}
}
private void HandleErrorMsgBoxBtnClick(object? sender, RoutedEventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsErrorMsgBoxOpened = true;
}
}
private void HandleWarningMsgBoxBtnClick(object? sender, RoutedEventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsWarningMsgBoxOpened = true;
}
}
private void HandleStyleCaseHostTypeSwitchChanged(object? sender, RoutedEventArgs e)
{
if (sender is ToggleSwitch toggleSwitch)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.MessageBoxStyleCaseHostType = toggleSwitch.IsChecked == true ? DialogHostType.Window : DialogHostType.Overlay;
}
}
}
private void HandleLoadingDialogOpenModalButtonClick(object? sender, RoutedEventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsLoadingMsgBoxOpened = true;
}
}
private void HandleLoadingDialogOpened(object? sender, EventArgs e)
{
if (sender is Dialog dialog)
{
DispatcherTimer.RunOnce(() =>
{
dialog.IsLoading = false;
}, TimeSpan.FromMilliseconds(3000));
}
}
private void HandleLoadingDialogButtonClicked(object? sender, DialogButtonClickedEventArgs e)
{
if (sender is Dialog dialog)
{
dialog.IsLoading = true;
DispatcherTimer.RunOnce(() =>
{
dialog.IsLoading = false;
}, TimeSpan.FromMilliseconds(3000));
}
}
private void HandleAsyncDialogOpenModalButtonClick(object? sender, RoutedEventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsAsyncDialogOpened = true;
}
}
private void HandleAsyncDialogButtonClicked(object? sender, DialogButtonClickedEventArgs e)
{
if (sender is Dialog dialog && e.SourceButton.Role == DialogButtonRole.AcceptRole)
{
dialog.IsConfirmLoading = true;
e.Handled = true;
DispatcherTimer.RunOnce(() =>
{
dialog.IsConfirmLoading = false;
dialog.Done();
}, TimeSpan.FromMilliseconds(3000));
}
}
private void HandleCustomFooterDialogOpenButtonClick(object? sender, EventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsCustomFooterDialogOpened = true;
}
}
private void HandleCustomFooterMsgBoxOpenButtonClick(object? sender, EventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsCustomFooterMsgBoxOpened = true;
}
}
private void HandleDraggableMsgBoxOpenButtonClick(object? sender, EventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsDraggableMsgBoxOpened = true;
}
}
private void HandleDelayedCloseMsgBoxOpenButtonClick(object? sender, EventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsDelayedCloseMsgBoxOpened = true;
}
}
private IDisposable? _delayedCloseDialogDisposal;
private void HandleDelayedCloseMsgBoxOpened(object? sender, EventArgs e)
{
if (sender is MessageBox messageBox)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.CountdownSeconds = 5;
_delayedCloseDialogDisposal?.Dispose();
_delayedCloseDialogDisposal = DispatcherTimer.Run(() =>
{
if (viewModel.CountdownSeconds == 0)
{
messageBox.Confirm();
return false;
}
viewModel.CountdownSeconds--;
return true;
}, TimeSpan.FromMilliseconds(1000));
}
}
}
private void HandleConfigureButtonsDialogButtonClick(object? sender, EventArgs e)
{
if (DataContext is ModalViewModel viewModel)
{
viewModel.IsConfigureButtonsDialogOpened = true;
}
}
private void ConfigureButtonProperties(IReadOnlyList<DialogButton> buttons)
{
foreach (var button in buttons)
{
button.IsEnabled = false;
}
}
}
view-model文件：
using AtomUI.Controls;
using ReactiveUI;
namespace AtomUIGallery.ShowCases.ViewModels;
public class ModalViewModel : ReactiveObject, IRoutableViewModel
{
public const string ID = "Modal";
public IScreen HostScreen { get; }
public string UrlPathSegment { get; } = ID;
private bool _isBasicModalOpened;
public bool IsBasicModalOpened
{
get => _isBasicModalOpened;
set => this.RaiseAndSetIfChanged(ref _isBasicModalOpened, value);
}
private bool _isBasicWindowModalOpened;
public bool IsBasicWindowModalOpened
{
get => _isBasicWindowModalOpened;
set => this.RaiseAndSetIfChanged(ref _isBasicWindowModalOpened, value);
}
private DialogHostType _messageBoxStyleCaseHostType;
public DialogHostType MessageBoxStyleCaseHostType
{
get => _messageBoxStyleCaseHostType;
set => this.RaiseAndSetIfChanged(ref _messageBoxStyleCaseHostType, value);
}
private bool _isConfirmMsgBoxOpened;
public bool IsConfirmMsgBoxOpened
{
get => _isConfirmMsgBoxOpened;
set => this.RaiseAndSetIfChanged(ref _isConfirmMsgBoxOpened, value);
}
private bool _isInformationMsgBoxOpened;
public bool IsInformationMsgBoxOpened
{
get => _isInformationMsgBoxOpened;
set => this.RaiseAndSetIfChanged(ref _isInformationMsgBoxOpened, value);
}
private bool _isSuccessMsgBoxOpened;
public bool IsSuccessMsgBoxOpened
{
get => _isSuccessMsgBoxOpened;
set => this.RaiseAndSetIfChanged(ref _isSuccessMsgBoxOpened, value);
}
private bool _isErrorMsgBoxOpened;
public bool IsErrorMsgBoxOpened
{
get => _isErrorMsgBoxOpened;
set => this.RaiseAndSetIfChanged(ref _isErrorMsgBoxOpened, value);
}
private bool _isWarningMsgBoxOpened;
public bool IsWarningMsgBoxOpened
{
get => _isWarningMsgBoxOpened;
set => this.RaiseAndSetIfChanged(ref _isWarningMsgBoxOpened, value);
}
private bool _isLoadingMsgBoxOpened;
public bool IsLoadingMsgBoxOpened
{
get => _isLoadingMsgBoxOpened;
set => this.RaiseAndSetIfChanged(ref _isLoadingMsgBoxOpened, value);
}
private bool _isAsyncDialogOpened;
public bool IsAsyncDialogOpened
{
get => _isAsyncDialogOpened;
set => this.RaiseAndSetIfChanged(ref _isAsyncDialogOpened, value);
}
private bool _isCustomFooterDialogOpened;
public bool IsCustomFooterDialogOpened
{
get => _isCustomFooterDialogOpened;
set => this.RaiseAndSetIfChanged(ref _isCustomFooterDialogOpened, value);
}
private bool _isCustomFooterMsgBoxOpened;
public bool IsCustomFooterMsgBoxOpened
{
get => _isCustomFooterMsgBoxOpened;
set => this.RaiseAndSetIfChanged(ref _isCustomFooterMsgBoxOpened, value);
}
private bool _isDraggableMsgBoxOpened;
public bool IsDraggableMsgBoxOpened
{
get => _isDraggableMsgBoxOpened;
set => this.RaiseAndSetIfChanged(ref _isDraggableMsgBoxOpened, value);
}
private bool _isDelayedCloseMsgBoxOpened;
public bool IsDelayedCloseMsgBoxOpened
{
get => _isDelayedCloseMsgBoxOpened;
set => this.RaiseAndSetIfChanged(ref _isDelayedCloseMsgBoxOpened, value);
}
private int _countdownSeconds;
public int CountdownSeconds
{
get => _countdownSeconds;
set => this.RaiseAndSetIfChanged(ref _countdownSeconds, value);
}
private bool _isConfigureButtonsDialogOpened;
public bool IsConfigureButtonsDialogOpened
{
get => _isConfigureButtonsDialogOpened;
set => this.RaiseAndSetIfChanged(ref _isConfigureButtonsDialogOpened, value);
}
public ModalViewModel(IScreen screen)
{
HostScreen = screen;
}
}