WPF - 通过事件执行命令

本文关键字：执行 命令 事件 WPF | 更新日期: 2023-09-27 18:33:10

WPF - 通过事件命令

我已经通过命令处理了TextChanged事件。 

<TextBox Text="{Binding ConnectionString, Mode=TwoWay}" xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity">
                <i:Interaction.Triggers>
                    <i:EventTrigger EventName="TextChanged">
                        <i:InvokeCommandAction Command="{Binding Path=SomeCommand, Mode=OneWay}"/>
                    </i:EventTrigger>
                </i:Interaction.Triggers>
            </TextBox>

我的参考资料：

- Microsoft.Expression.Interactions
- Systsem.Windwos.Interactivity

例外：

类型的第一次机会异常 "System.Windows.Markup.XamlParseException" 发生在 演示框架.dll

其他信息：无法加载文件或程序集 "System.Windows.Interactivity， PublicKeyToken=31bf3856ad364e35" 或一个 的依赖关系。系统找不到指定的文件。

WPF - 通过事件执行命令

这对你有用吗？

XAML-

<Window x:Class="garbage.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<Grid>
    <TextBox Text="{Binding ConnectionString, Mode=TwoWay}" xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity">
        <i:Interaction.Triggers>
            <i:EventTrigger EventName="TextChanged">
                <i:InvokeCommandAction Command="{Binding Path=SomeCommand, Mode=OneWay}"/>
            </i:EventTrigger>
        </i:Interaction.Triggers>
    </TextBox>
</Grid>

代码隐藏

    using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace garbage
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            DataContext = this;
            SomeCommand = new RelayCommand(SomeCommandExecute, CanExecute);
        }
        private ICommand someCommand;
        public ICommand SomeCommand
        {
            get
            {
                return someCommand;
            }
            set
            {
                someCommand = value;
            }
        }
        public void SomeCommandExecute(object something)
        {
            MessageBox.Show("Success");
        }
        private bool CanExecute(object thing)
        { return true; }
    }
}

中继命令.cs

    using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
namespace garbage
{
    public class RelayCommand : ICommand
    {
        private Action<object> execute;
        private Predicate<object> canExecute;
        private event EventHandler CanExecuteChangedInternal;
        public RelayCommand(Action<object> execute)
            : this(execute, DefaultCanExecute)
        {
        }
        public RelayCommand(Action<object> execute, Predicate<object> canExecute)
        {
            if (execute == null)
            {
                throw new ArgumentNullException("execute");
            }
            if (canExecute == null)
            {
                throw new ArgumentNullException("canExecute");
            }
            this.execute = execute;
            this.canExecute = canExecute;
        }
        public event EventHandler CanExecuteChanged
        {
            add
            {
                CommandManager.RequerySuggested += value;
                this.CanExecuteChangedInternal += value;
            }
            remove
            {
                CommandManager.RequerySuggested -= value;
                this.CanExecuteChangedInternal -= value;
            }
        }
        public bool CanExecute(object parameter)
        {
            return this.canExecute != null && this.canExecute(parameter);
        }
        public void Execute(object parameter)
        {
            this.execute(parameter);
        }
        public void OnCanExecuteChanged()
        {
            EventHandler handler = this.CanExecuteChangedInternal;
            if (handler != null)
            {
                //DispatcherHelper.BeginInvokeOnUIThread(() => handler.Invoke(this, EventArgs.Empty));
                handler.Invoke(this, EventArgs.Empty);
            }
        }
        public void Destroy()
        {
            this.canExecute = _ => false;
            this.execute = _ => { return; };
        }
        private static bool DefaultCanExecute(object parameter)
        {
            return true;
        }
    }
}
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