Csharp CsWin32如何创建PWSTR的实例，例如GetWindowText

发布于04月10日

I just started using CsWin32 and one of the Win32 functions I want to use it GetWindowText which gets mapped to I know how to work with the first and last parameter, but I don't know what to do with the one in the middle, the PWSTR lpString. How do I create an instance of that? The source code for PWSTR looks like this (excerpt):

internal unsafe readonly partial struct PWSTR
    : IEquatable<PWSTR>
{
    // ...
    internal PWSTR(char* value) => this.Value = value;
    // ...
}

我想我必须这样做

PWSTR lpString = new PWSTR(<what to do here>);

但我不知道如何在C#中创建一个char*或等价的代码？

推荐答案

try 使用指针.你必须使用unsafe和fixed. 下面是一个例子.讨论(https://github.com/microsoft/CsWin32/discussions/181)

没有编译和测试.

   int bufferSize = PInvoke.GetWindowTextLength(handle) + 1;
   unsafe // BELOW CODE INVOLVES POINTERS.
   {
       //ADDRESS WONT CHANGE, THIS VARIABLE SHOULD BE USED WITH IN THIS SCOPE.
       fixed (char* windowNameChars = new char[bufferSize]) 
       {
           if (PInvoke.GetWindowText(handle, windowNameChars, bufferSize) == 0)
           {
               int errorCode = Marshal.GetLastWin32Error();
               if (errorCode != 0)
               {
                   throw new Win32Exception(errorCode);
               }

               return true;
           }

           string windowName = new string(windowNameChars);
       }

       return true;
   }