You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: main.go
    path of file: ./repos/govcl/samples/Windows/gdiplustest
    
    the code of the file until where you have to start completion: // +build windows

package main

import (
	"fmt"

	"github.com/tryor/gdiplus"
	"github.com/tryor/winapi"
	_ "github.com/ying32/govcl/pkgs/winappres"
	"github.com/ying32/govcl/vcl"
)

var (
	gpToken winapi.ULONG_PTR
)

// 用了
    
func main() {

	_, err := gdiplus.Startup(&gpToken, nil, nil)
	if err != nil {
		if err != nil {
			vcl.ShowMessage("初始GDI+失败，错误:" + err.Error())
		}
	} else {
		fmt.Println("gdi+实始成功")
		defer gdiplus.Shutdown(gpToken)
	}

	vcl.Application.SetOnException(func(sender vcl.IObject, e *vcl.Exception) {
		// 在这里自行处理VCL中的异常
	})

	vcl.Application.Initialize()
	vcl.Application.SetMainFormOnTaskBar(true)
	vcl.Application.CreateForm(&GdipForm)
	vcl.Application.Run()

}