WPF中命令(Command)简单使用绑定(一)

本章我们来讲述:WPF中命令(Command)的绑定和使用的简单示例。

首先我们要先定义一个类,并继承ICommand;

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;

namespace ICommandTest
{
    public class RelayCommand : ICommand
    {
        private readonly Action m_execute;
        private readonly Predicate m_canExecute;

        public RelayCommand(Action execute)
        {
            this.m_execute = execute;
        }

        public RelayCommand(Action execute, Predicate canExecute)
        {
            this.m_execute = execute;
            this.m_canExecute = canExecute;
        }

        public bool CanExecute(object parameter)
        {
            if (m_canExecute == null)
                return true;

            return m_canExecute(parameter);
        }

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

        public void Execute(object parameter)
        {
            this.m_execute(parameter);
        }
    }
}
 
  

然后在界面上绑定命令


    
        
        

后台上下文数据绑定ViewModel

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 ICommandTest
{
    /// 
    /// MainWindow.xaml 的交互逻辑
    /// 
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            this.DataContext = new MainWindowViewModel(); 
        }
    }
}

ViewModel

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;

namespace ICommandTest
{
    public class MainWindowViewModel
    {
        public RelayCommand ClickCommand
        {
            get
            {
                return new RelayCommand((arg) =>
                {
                    string context = arg as string;
                    MessageBox.Show("Click " + context);
                });
            }
        }

        public RelayCommand ClickCommand2
        {
            get
            {
                return new RelayCommand((arg) =>
                {
                    TextBox context = arg as TextBox;
                    MessageBox.Show("Click " + context.Text);
                });
            }
        }
    }
}

这样就简单实现了命令的绑定和使用,运行测试结果图

WPF中命令(Command)简单使用绑定(一)_第1张图片    WPF中命令(Command)简单使用绑定(一)_第2张图片

 

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