How do I use Windows.h in c++/clr - windows

Question

I am making an app that has a button that attaches to a running process but when I try to use windows.h functions eg. FindWindowA it says unresolved token (0A000038) extern C.
if working correctly it should attach to process when the button is pressed and then run some code that i havent coded in yet
Here is the button code
#pragma once
#include<Windows.h>
namespace projname {
using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;
/// <summary>
/// Summary for MyForm
/// </summary>
public ref class MyForm : public System::Windows::Forms::Form
{
public:
MyForm(void)
{
InitializeComponent();
//
//TODO: Add the constructor code here
//
}
protected:
/// <summary>
/// Clean up any resources being used.
/// </summary>
~MyForm()
{
if (components)
{
delete components;
}
}
private: System::Windows::Forms::Button^ injectButton;
protected:
private: System::Windows::Forms::TextBox^ windowName;
private:
/// <summary>
/// Required designer variable.
/// </summary>
System::ComponentModel::Container ^components;
#pragma region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
void InitializeComponent(void)
{
this->injectButton = (gcnew System::Windows::Forms::Button());
this->windowName = (gcnew System::Windows::Forms::TextBox());
this->SuspendLayout();
//
// injectButton
//
this->injectButton->Font = (gcnew System::Drawing::Font(L"MS UI Gothic", 48, System::Drawing::FontStyle::Bold, System::Drawing::GraphicsUnit::Point,
static_cast<System::Byte>(0)));
this->injectButton->Location = System::Drawing::Point(12, 384);
this->injectButton->Name = L"injectButton";
this->injectButton->Size = System::Drawing::Size(537, 87);
this->injectButton->TabIndex = 0;
this->injectButton->Text = L"Inject";
this->injectButton->UseVisualStyleBackColor = true;
this->injectButton->Click += gcnew System::EventHandler(this, &MyForm::injectButton_Click);
//
// windowName
//
this->windowName->Location = System::Drawing::Point(13, 358);
this->windowName->Name = L"windowName";
this->windowName->Size = System::Drawing::Size(536, 20);
this->windowName->TabIndex = 1;
this->windowName->Text = L"Window Name";
//
// MyForm
//
this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
this->ClientSize = System::Drawing::Size(561, 483);
this->Controls->Add(this->windowName);
this->Controls->Add(this->injectButton);
this->Name = L"MyForm";
this->Text = L"projname";
this->ResumeLayout(false);
this->PerformLayout();
}
#pragma endregion
private: System::Void injectButton_Click(System::Object^ sender, System::EventArgs^ e) {
HWND hwnd = FindWindowA(NULL, "window to attach to");
if (hwnd == NULL) { exit(-1); }
else {
DWORD procID;
GetWindowThreadProcessId(hwnd, &procID);
HANDLE handle = OpenProcess(PROCESS_ALL_ACCESS, FALSE, procID);
if (procID == NULL) { exit(-1); }
}
}
};
}

Answer 1

If you add kernel32.lib and a few others to linker it works if you need more help search up
unresolved token (0A000038) extern C and there is a stack overflow question