在 wpf C# 中單擊按鈕時如何禁用其他功能

Question

 I have a screen in WPF like that (WPF MVVM C#)I want to when I clicked the generate reports button.All of other functions will be disable.(without button) 

我怎樣才能做到這一點？ 我等待你的想法（就像在網格中）我可以像所有這些綁定 IsEnabled 一樣做到這一點。 但我不想那樣做。

<CheckBox x:Name="IncludeEmployeesCheckBox" Content="Include All Employees" IsChecked="{Binding IncludeAllEmployees, Mode=TwoWay}" Margin="4" />
                <CheckBox Content="Exclude Weekends" IsChecked="{Binding ExcludeWeekends}" Margin="4" />
                <CheckBox Content="Exclude Former Employees" IsChecked="{Binding ExcludeFormerEmployees}" Margin="4" />
                <CheckBox Content="Exclude Public Holidays" IsChecked="{Binding ExcludePublicHolidays}" Margin="4" />
               
                <Button Content="Generate Reports" Command="{Binding GenerateReportsCommand}" Height="36" Margin="4" />

感謝您的所有幫助。

Answer 1

假設您的報告生成 function 運行時間足夠長以證明使用 async / await 模式是合理的，請為 GenerateReportsCommand 使用異步命令 class。

public abstract class perCommandBase : ICommand
{
    // ICommand members
    public abstract bool CanExecute(object parameter);
    public abstract void Execute(object parameter);
    public event EventHandler CanExecuteChanged;

    public void RaiseCanExecuteChanged()
    {
        CanExecuteChanged?.Invoke(this, EventArgs.Empty);
    }
}

public class perRelayCommandAsync : perCommandBase, INotifyPropertyChanged
{
    private readonly Func<Task> _execute;
    private readonly Func<bool> _canExecute;

    public perRelayCommandAsync(Func<Task> execute) : this(execute, () => true)
    {
    }

    public perRelayCommandAsync(Func<Task> execute, Func<bool> canExecute)
    {
        _execute = execute ?? throw new ArgumentNullException(nameof(execute));
        _canExecute = canExecute;
    }

    private bool _isExecuting;

    /// <summary>
    /// Is the command currently executing
    /// </summary>
    public bool IsExecuting
    {
        get => _isExecuting;
        set
        {
            _isExecuting = value;
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(IsExecuting)));
            RaiseCanExecuteChanged();
        }
    }

    public override bool CanExecute(object parameter) => !IsExecuting && _canExecute();

    public override async void Execute(object parameter)
    {
        if (!CanExecute(parameter))
        {
            return;
        }

        IsExecuting = true;
        try
        {
            var response = await _execute()
                .ExecuteActionWithTimeoutAsync(ExecuteTimeOut)
                .ConfigureAwait(true);

            if (response.IsTimedOut)
            {
                OnTimeOutAction?.Invoke(response);
            }
            else if (response.IsError)
            {
                OnErrorAction?.Invoke(response);
            }
        }
        finally
        {
            IsExecuting = false;
        }
    }

    /// <summary>
    /// Timeout value for Execute invocation
    /// </summary>
    public TimeSpan ExecuteTimeOut { get; set; } = perTimeSpanHelper.Forever;

    /// <summary>
    /// Optional action to perform if Execute generates an error.
    /// </summary>
    public Action<perAsyncActionResponse> OnErrorAction { get; set; }

    /// <summary>
    /// Optional action to perform if Execute times out.
    /// </summary>
    public Action<perAsyncActionResponse> OnTimeOutAction { get; set; }

    public event PropertyChangedEventHandler PropertyChanged;
}

由於CanExecute返回 false，當IsExecuting為 true 時， Button將自動禁用。 您還可以將其他控件的IsEnabled或IsVisible屬性綁定到GenerateReportsCommand.IsExecuting 。

關於如何將命令的 CanExecute 鏈接到我的博客文章中的其他屬性狀態的更多建議。

Answer 2

如果您使用 MVVM 模式，最好將 boolean 屬性與GenerateReportsCommand等長時間運行的操作相關聯。 然后，您可以使用該布爾屬性來隱藏/禁用 XAML 中的控件。

例如：

private bool busy;
public bool Busy { get => this.busy; set { this.busy = value; OnPropertyChanged(); } }

private async Task GenerateReportsAsync()
{
  // Set the Busy flag at the beginning of your long running operation
  Busy = true;

  // ... do your report generation here, which may take a long time

  // Clear the Busy flag at the end of your long running operation
  Busy = false;
}

在您的 xaml 中（我在這里使用 StackPanel，但任何 UIElement 都可以使用其 IsEnabled 或 Visibility 屬性：

<StackPanel>
    <CheckBox/>
    <CheckBox/>
    <CheckBox/>
    <StackPanel.Style>
        <Style TargetType="StackPanel">
            <Style.Triggers>
                <DataTrigger Binding="{Binding Busy}" Value="True">
                    <Setter Property="Visibility" Value="Collapsed"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </StackPanel.Style>
</StackPanel>
<Button Content="Generate Reports" Command="{Binding GenerateReportsCommand}" Height="36" Margin="4" />