Question

我想问一下，是否可以将视图（xaml）中的字符串值传递给ViewModel中的属性？

我有两个标签。首先是＆＃34;流程＆＃34;第二个是＆＃34;非流程＆＃34;。取决于该字符串值，RelayCommand将执行并使用DispatcherTimer触发方法（如果是Process然后是Dispatcher1，如果是Non-Process然后是Dispatcher2）。

XAML：

<i:Interaction.Triggers>
    <i:EventTrigger EventName="PreviewMouseDown" >
       <cmd:EventToCommand Command="{Binding EmployeeViewM.MeasurementEndExecution}"/>
    </i:EventTrigger>
</i:Interaction.Triggers>

我可以使用 CommandParameter 和 CommandParameterValue 将字符串传递给属性吗？

感谢您提出任何建议

Answer 1

是的，你可以，如下所示：

<i:Interaction.Triggers>
    <i:EventTrigger EventName="PreviewMouseDown" >
        <cmd:EventToCommand Command="{Binding EmployeeViewM.MeasurementEndExecution}" CommandParameter="Process"/>
    </i:EventTrigger>
</i:Interaction.Triggers>

和/或

<i:Interaction.Triggers>
    <i:EventTrigger EventName="PreviewMouseDown" >
        <cmd:EventToCommand Command="{Binding EmployeeViewM.MeasurementEndExecution}" CommandParameter="Non-Process"/>
    </i:EventTrigger>
</i:Interaction.Triggers>

希望您的RelayCommand（或ICommand实施）已经接受CommandParameter。如下所示。

 public class RelayCommand : ICommand
{
    #region Fields

    readonly Action<object> _execute;
    readonly Predicate<object> _canExecute;

    #endregion // Fields

    #region Constructors

    /// <summary>
    /// Creates a new command that can always execute.
    /// </summary>
    /// <param name="execute">The execution logic.</param>
    public RelayCommand(Action<object> execute)
        : this(execute, null)
    {
    }

    /// <summary>
    /// Creates a new command.
    /// </summary>
    /// <param name="execute">The execution logic.</param>
    /// <param name="canExecute">The execution status logic.</param>
    public RelayCommand(Action<object> execute, Predicate<object> canExecute)
    {
        if (execute == null)
            throw new ArgumentNullException("execute");

        _execute = execute;
        _canExecute = canExecute;
    }

    #endregion // Constructors

    #region ICommand Members


    public bool CanExecute(object parameter)
    {
        return _canExecute == null ? true : _canExecute(parameter);
    }

    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }

    public void Execute(object parameter)
    {
        _execute(parameter);
    }

    #endregion // ICommand Members
}

通过CommandParameter将String传递给方法

1 个答案: