如何添加程序集引用以在 c# 中使用 Rect？

Question

I want to use the Rect Struct and I write Rect aaa = new Rect(); and I get the type or namespace could not be found error. I try adding all the using s as in the example of the web:

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Shapes;

and I get in that the last three imports a the type or namespace Shapes does not exist in the namespace System.Windows. (are you missing an assembly reference?) the type or namespace Shapes does not exist in the namespace System.Windows. (are you missing an assembly reference?) .

At the webpage mentioned, it says the assembly is WindowsBase.dll . And now I don't know how to go on...

UPDATE: I've been told to add a reference, but it's a Core project and that's not possible .

I should install a package but I don't see any package containing this dll. The package WindowsBase is not valid for .net 5, but in the documentation above it says this Struc can be used indeed with .net 5.

I want to use this struct.

Answer 1

Short answer: As @imsmn commented, add a reference to WindowsBase. Do that by right clicking on the "References" entry in the Solution explorer and select "Add Reference".

Long answer (or more accurately, suggestion):

Easy way to get the answer in the future: For "built-in" classes that are not ambiguous, you can try this. In Visual Studio, in the code window (C# editor) type:

Rect r = new Rect();

Then hold your mouse over the red squiggly line that appears under the word "Rect". A box will pop-up and one of the options will be "Show Potential Fixes". If you click that, one of the options is often to add the reference (if necessary) and the using directive (if necessary).