我正在尝试从VS2012(Window 7)中的问题“Understanding ICommand implementation without MVVM”运行代码,但出现错误:
“Windows Presentation Foundation(WPF)项目不支持AppCommand”
那么,什么是错误的,或者应该怎么做才能从该问题运行代码?
MainWindow.xaml.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
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 seWPFUnderstandingICommandWithout_MVVM
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
AppCommands.AnyCommand.CanExecuteChanged += MyEventHandler;
}
private void button1_Click(object sender, RoutedEventArgs e)
{
// Nothing for the moment
}
private void MyEventHandler(object sender, EventArgs e)
{
Console.WriteLine("MyEventHandler called");
}
}
public static class AppCommands
{
private static ICommand anyCommand = new MyCommand();
public static ICommand AnyCommand
{
get { return anyCommand; }
}
}
public class MyCommand : ICommand
{
bool canExecute;
public void Execute(object parameter)
{
Console.WriteLine("Execute called!");
}
public bool CanExecute(object parameter)
{
Console.WriteLine("CanExecute called!");
return CanExecuteResult;
}
public event EventHandler CanExecuteChanged;
public bool CanExecuteResult
{
get { return canExecute; }
set
{
if (canExecute != value)
{
canExecute = value;
var canExecuteChanged = CanExecuteChanged;
if (canExecuteChanged != null)
canExecuteChanged.Invoke(this, EventArgs.Empty);
}
}
}
}
}
最佳答案
如果在AppCommands
命名空间中定义了Namespace.To.AppCommads
类,则需要在XAML中声明它:
xmlns:local="clr-namespace:Namespace.To.AppCommads"
并像这样使用它:
Command="{x:Static local:AppCommands.AppCommand}"
关于c# - Windows Presentation Foundation(WPF)项目不支持AppCommand,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/22305939/