golang 调用GdiPlus 打印

可以使用 Go 国际化方式（CGo）调用 GdiPlus 库来打印。以下是一个简单的示例：

package main

/*
#include <windows.h>
#include <gdiplus.h>

#pragma comment (lib,"Gdiplus.lib")

int print(const wchar_t *filename) {
    Gdiplus::GdiplusStartupInput input;
    ULONG_PTR token;

    Gdiplus::GdiplusStartup(&token, &input, NULL);

    Gdiplus::Image* image = new Gdiplus::Image(filename);

    HDC hdc = GetDC(NULL);
    HDC hdcPrn = CreateDC(L"WINSPOOL", NULL, NULL, NULL);

    RECT prnRect;
    prnRect.left = prnRect.top = 0;
    prnRect.right = GetDeviceCaps(hdcPrn, PHYSICALWIDTH);
    prnRect.bottom = GetDeviceCaps(hdcPrn, PHYSICALHEIGHT);

    HDC hdcMem = CreateCompatibleDC(hdcPrn);
    HBITMAP hBmp = CreateCompatibleBitmap(hdcPrn, prnRect.right, prnRect.bottom);
    SelectObject(hdcMem, hBmp);

    Gdiplus::Graphics graphics(hdcMem);
    graphics.DrawImage(image, 0, 0, prnRect.right, prnRect.bottom);

    DOCINFO di;
    ZeroMemory(&di, sizeof(DOCINFO));
    di.cbSize = sizeof(DOCINFO);
    di.lpszDocName = L"Test Print";
    StartDoc(hdcPrn, &di);
    StartPage(hdcPrn);
    BitBlt(hdcPrn, 0, 0, prnRect.right, prnRect.bottom, hdcMem, 0, 0, SRCCOPY);
    EndPage(hdcPrn);
    EndDoc(hdcPrn);

    DeleteDC(hdcPrn);
    DeleteObject(hBmp);
    DeleteDC(hdcMem);
    ReleaseDC(NULL, hdc);

    delete image;

    Gdiplus::GdiplusShutdown(token);

    return 0;
}
*/
import "C"
import (
    "unsafe"
)

func main() {
    filename := "test.png"
    cname := C.CString(filename)
    defer C.free(unsafe.Pointer(cname))

    C.print(cname)
}

这个示例将加载一个 PNG 图像文件并将其打印到默认打印机上。它使用 GdiPlus 库来绘制图像和打印输出。在 Go 中使用 CGo 调用 C 函数，可以轻松地与 Windows API 进行交互并使用 GdiPlus 库进行绘图和打印操作。