从F＃访问WPF（XAML）元素？

Let's say I have this xaml code :

假设我有这个xaml代码：

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Canvas>
        <Rectangle Name="papan" Fill="Red" Height="20" Width="20" />
    </Canvas>
</Window>

And I have a file named Program.fs (F# code), how can I access "papan", for example, from my code?

我有一个名为Program.fs（F＃代码）的文件，如何从我的代码中访问“papan”？

Thanks

谢谢

2 个解决方案

#1

Something like this?

像这样的东西？

open System.Windows
open System.Windows.Markup
open System.Windows.Shapes

let xaml = @"<Window xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'
    xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
    <Canvas>
        <Rectangle Name='papan' Fill='Red' Height='20' Width='20' />
    </Canvas>
</Window>"

let wnd = XamlReader.Parse(xaml) :?> Window
let rect = wnd.FindName("papan") :?> Rectangle

If the XAML is in a separate file, you can use XamlReader.Load instead of XamlReader.Parse.

如果XAML位于单独的文件中，则可以使用XamlReader.Load而不是XamlReader.Parse。

#2

In addition to the answer posted by kvb, you can use F# dynamic invoke operator (which is similar to dynamic in C# 4.0) to get a nicer syntax. The operator allows you to define the meaning of expressions such as wnd?papan. You can for example specify that this should perform the lookup using FindName method. The operator definition looks like this:

除了kvb发布的答案之外，您还可以使用F＃动态调用运算符（类似于C＃4.0中的动态）来获得更好的语法。运算符允许您定义表达式的含义，例如wnd？papan。例如，您可以指定这应该使用FindName方法执行查找。运算符定义如下所示：

let (?) (this : Control) (prop : string) : 'T = // '
  this.FindName(prop) :?> 'T

Then you can just write:

然后你可以写：

let rect : Rectangle = wnd?papan

You still need to write the type (Rectangle) explicitly, so that F# type inference can use it, but the syntax is a bit more comfortable.

您仍然需要显式地编写类型（Rectangle），以便F＃类型推断可以使用它，但语法更舒适一点。

#1