类库不承认的CommandManager类 [英] Class library does not recognize CommandManager class

问题描述

我开发WPF应用程序，我想重用我的课是相同的所有这些应用程序，所以我可以将其添加为引用。

I'm developing WPF applications and I want to reuse my classes that are the same in all those applications so I can add them as a reference.

在我情况下，我有我的命令一类：

In my case I have a class for my Commands:

public class RelayCommand : ICommand
{
    #region Fields

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

    #endregion // Fields

    #region Constructors

    public RelayCommand(Action<object> execute)
        : this(execute, null)
    {

    }

    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
}

这完美的作品在我的应用程序，但是当我想打一个类库，我只想补充在我的项目时，Visual Studio不能因为建设一参命令管理不存在于当前上下文。在我usings我有使用系统（这应该是足够了）

This works perfect in my application, but when I want to make a class library which I just want to add as a reference in my project, visual studio can't build because "CommandManager does not exists in the current context". In my usings I have the following (which should be enough)

 using System;
 using System.Windows.Input;

任何想法，为什么我不能这样做在一个类库项目？

Any ideas why I can't do this in a "class library project" ?

推荐答案

转到您的类库的参考部分，选择添加引用。寻找所谓的PresentationCore的组装和添加。

Go to the "References" part of your class library and select "Add Reference". Look for an assembly called "PresentationCore" and add it.

然后在你的类文件中添加using语句使用System.Windows.Input;

Then in your class file add the using statement using System.Windows.Input;

您都能够像您期望访问的CommandManager

You will then be able to access the CommandManager as you expect.

只是增加：很多球员，当他们去创建一个类图书馆，他们选择自定义WPF控件库，然后删除将Class1.cs文件。这是一个快捷方式自动添加合适的命名空间到库中。无论是好还是坏的快捷键是任何人的电话，我却用它所有的时间。

Just adding: lots of guys when they go to create a class library, they select "WPF Custom Control Library" and then erase the "Class1.cs" file. It's a shortcut that automatically adds the right namespaces to your library. Whether it's a good or bad shortcut is anybody's call, but I use it all the time.

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