C# 使用全局变量的 WPF 应用程序

WPF Application using a global variable

提问by Jake

I created a WPF application in c# with 3 different windows, Home.xaml, Name.xaml, Config.xaml. I want to declare a variable in Home.xaml.csthat I can use in both the other forms. I tried doing public string wt = "";but that didn't work.

我在 c# 中创建了一个 WPF 应用程序，其中包含 3 个不同的窗口，Home.xaml, Name.xaml, Config.xaml。我想声明一个变量Home.xaml.cs，我可以在其他两种形式中使用它。我尝试这样做，public string wt = "";但没有奏效。

How can I make it usable by all three forms?

我怎样才能使它对所有三种形式都可用？

回答by Eduardo Cobuci

You can use a static property:

您可以使用静态属性：

public static class ConfigClass()
{
    public static int MyProperty { get; set; }
}

Edit:

编辑：

The idea here is create a class that you holds all "common data", typically configurations. Of course, you can use any class but suggest you to use a static class. You can access this property like this:

这里的想法是创建一个类来保存所有“公共数据”，通常是配置。当然，您可以使用任何类，但建议您使用静态类。您可以像这样访问此属性：

Console.Write(ConfigClass.MyProperty)

回答by Ari Roth

There are two different things you can do here (among others; these are just the two that come to mind first).

您可以在这里做两种不同的事情（除其他外；这只是首先想到的两种）。

1. You could make the variable static on Home.xaml.cs

   public static string Foo = "";

2. You could just pass in the variable to all three forms.

1. 您可以在 Home.xaml.cs 上将变量设为静态

   公共静态字符串 Foo = "";

2. 您可以将变量传递给所有三种形式。

I would go with #2, myself, and if necessary create a separate class that contains the data I need. Then each class would have access to the data.

我会选择#2，我自己，如果有必要，创建一个单独的类来包含我需要的数据。然后每个类都可以访问数据。

回答by Henk Holterman

The proper way, especially if you ever want to move to XBAPP, is to store it in

正确的方法，特别是如果你想移动到 XBAPP，是将它存储在

Application.Current.Properties

which is a Dictionary object.

这是一个 Dictionary 对象。

回答by Dustin Pauze

To avoid having to pass around values between windows and usercontrols, or creating a static class to duplicate existing functionality within WPF, you could use:

为了避免在窗口和用户控件之间传递值，或创建静态类来复制 WPF 中的现有功能，您可以使用：

• setting: App.Current.Properties["NameOfProperty"] = 5;
• getting: string myProperty = App.Current.Properties["NameOfProperty"];

• 环境： App.Current.Properties["NameOfProperty"] = 5;
• 得到： string myProperty = App.Current.Properties["NameOfProperty"];

This was mentioned above, but the syntax was a little off.

这是上面提到的，但语法有点不对。

This provides global variables within your application, accessible from any code running within it.

这在您的应用程序中提供了全局变量，可从其中运行的任何代码访问。

回答by duyanhphamkiller

App.xaml:

应用程序.xaml：

<Application x:Class="WpfTutorialSamples.App"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:sys="clr-namespace:System;assembly=mscorlib"
         StartupUri="WPF application/ResourcesFromCodeBehindSample.xaml">
<Application.Resources>
    <sys:String x:Key="strApp">Hello, Application world!</sys:String>
</Application.Resources>

code behind

背后的代码

Application.Current.FindResource("strApp").ToString()

回答by Mark Adamantine

As other people mentioned before either use App.Current.Propertiesor create a static class. I am here to provide an example for those who need more guidance with the static class.

正如之前提到的其他人使用App.Current.Properties或创建静态类。我在这里为那些需要更多静态类指导的人提供一个示例。

1. Add a new Class

1. 添加新班级

Right-click your project name in your solution explorer Add > New Itemchoose Classgive it a name (I usually name it GLOBALS)

在解决方案资源管理器中右键单击您的项目名称，Add > New Item选择Class给它一个名称（我通常将其命名为 GLOBALS）

1. What that cs file should look like

2. 那个 cs 文件应该是什么样子的

using System;

namespace ProjectName
{
    public static class GLOBALS
    {
        public static string Variable1 { get; set; }
        public static int Variable2 { get; set; }
        public static MyObject Variable3 { get; set; }
    }
}

1. Add references into .cs files where you intend to use those variables

3. 将引用添加到您打算使用这些变量的 .cs 文件中

using ProjectName

using ProjectName

1. We're done. Use it. Examples:

4. 我们完成了。用它。例子：

GLOBALS.Variable1 = "MyName"
Console.Write(GLOBALS.Variable1)
GLOBALS.Variable2 = 100;
GLOBALS.Variable2 += 20;
GLOBALS.Variable3 = new MyObject();
GLOBALS.Variable3.MyFunction();

On a side note, do notice that using the static class as global variables in c# is considered a bad practice (that's why there is no official implementation for globals), but I consider it a shortcut for when I am too lazy haha. It should not be used in the professional environment.

附带说明一下，请注意在 c# 中使用静态类作为全局变量被认为是一种不好的做法（这就是为什么没有全局变量的官方实现），但我认为这是我太懒时的捷径哈哈。它不应该在专业环境中使用。