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C++与C#使用GDI+创建PNG并旋转文本的对比实现

news 2025/10/20 10:06:24

以下是使用GDI+在C++和C#中创建PNG图片并写入旋转30度文本的实现对比：

特性	C++实现	C#实现
‌代码量‌	约50行	约15行
‌初始化‌	需要显式初始化GDI+环境	自动处理GDI+初始化
‌核心类‌	`Gdiplus::Bitmap`, `Gdiplus::Graphics`	`System.Drawing.Bitmap`, `System.Drawing.Graphics`
‌旋转实现‌	使用`Matrix`类或`RotateTransform`	直接使用`RotateTransform`方法
‌保存格式‌	需要获取PNG编码器CLSID	直接指定保存格式为PNG
‌资源释放‌	需要手动释放GDI+对象	可使用`using`语句自动释放

C#画图，只要9行代码,VC++要50行代码

VC++纯api调用gdiplus.dll要100行左右的代码

using System.Drawing;
using System.Drawing.Imaging;class Program {static void Main() {// 创建位图using(var bitmap = new Bitmap(400, 200)) {using(var graphics = Graphics.FromImage(bitmap)) {// 设置背景色graphics.Clear(Color.White);// 设置文本属性var font = new Font("Arial", 24);var brush = new SolidBrush(Color.Black);// 旋转并绘制文本graphics.TranslateTransform(100, 50);graphics.RotateTransform(30);graphics.DrawString("helloworld", font, brush, 0, 0);}// 保存为PNGbitmap.Save("output.png", ImageFormat.Png);}}
}

关键差异分析

‌初始化过程‌：
- C++需要显式初始化和清理GDI+环境
- C#自动处理GDI+的初始化和资源管理
‌资源管理‌：
- C++需要手动释放所有GDI+对象
- C#可利用using语句自动释放资源
‌图像保存‌：
- C++需要获取PNG编码器的CLSID
- C#直接使用ImageFormat.Png枚举值
‌代码复杂度‌：
- C++实现需要更多样板代码
- C#语法更简洁，框架提供了更多便利方法
‌旋转实现‌：
- 两者都使用RotateTransform方法
- C#的API设计更加直观易用

适用场景建议

‌选择C++‌：当需要最高性能、直接系统级访问或与现有C++代码库集成时
‌选择C#‌：当开发效率、代码简洁性和快速原型开发是首要考虑因素时

两种语言都能很好地完成GDI+图像处理任务，但C#的实现通常更为简洁高效，特别是在.NET环境下开发时。

VC++用GDIPLUS库画图，50行代码

#include <windows.h>
#include <gdiplus.h>
#include <iostream>
using namespace Gdiplus;int main() {// 初始化GDI+GdiplusStartupInput gdiplusStartupInput;ULONG_PTR gdiplusToken;GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);// 创建位图Bitmap bitmap(400, 200, PixelFormat32bppARGB);Graphics graphics(&bitmap);// 设置背景色graphics.Clear(Color(255, 255, 255, 255));// 设置文本属性Font font(L"Arial", 24);SolidBrush brush(Color(255, 0, 0, 0));PointF point(100.0f, 50.0f);// 旋转文本30度graphics.TranslateTransform(point.X, point.Y);graphics.RotateTransform(30.0f);graphics.DrawString(L"helloworld", -1, &font, PointF(0, 0), &brush);graphics.ResetTransform();// 保存为PNGCLSID pngClsid;GetEncoderClsid(L"image/png", &pngClsid);bitmap.Save(L"output.png", &pngClsid, NULL);// 清理GDI+GdiplusShutdown(gdiplusToken);return 0;
}// 获取编码器CLSID
int GetEncoderClsid(const WCHAR* format, CLSID* pClsid) {UINT num = 0, size = 0;GetImageEncodersSize(&num, &size);if(size == 0) return -1;ImageCodecInfo* pImageCodecInfo = (ImageCodecInfo*)malloc(size);GetImageEncoders(num, size, pImageCodecInfo);for(UINT i = 0; i < num; i++) {if(wcscmp(pImageCodecInfo[i].MimeType, format) == 0) {*pClsid = pImageCodecInfo[i].Clsid;free(pImageCodecInfo);return i;}}free(pImageCodecInfo);return -1;
}

VC++纯api调用gdiplus.dll要100行左右的代码


#include <windows.h>
#include <objidl.h>
#include <stdio.h>// 手动定义GDI+结构体
typedef struct {UINT32 GdiplusVersion;void* DebugEventCallback;BOOL SuppressBackgroundThread;BOOL SuppressExternalCodecs;
} GdiplusStartupInput;// 声明函数指针类型
typedef int (WINAPI* GdiplusStartupFunc)(ULONG_PTR*, const GdiplusStartupInput*, void*);
typedef void (WINAPI* GdiplusShutdownFunc)(ULONG_PTR);
typedef int (WINAPI* GdipCreateBitmapFromScan0Func)(int, int, int, int, void*, void**);
typedef int (WINAPI* GdipGetImageGraphicsContextFunc)(void*, void**);
typedef int (WINAPI* GdipGraphicsClearFunc)(void*, DWORD);
typedef int (WINAPI* GdipCreateFontFunc)(void*, float, int, int, void**);
typedef int (WINAPI* GdipCreateSolidFillFunc)(DWORD, void**);
typedef int (WINAPI* GdipSetTextRenderingHintFunc)(void*, int);
typedef int (WINAPI* GdipDrawStringFunc)(void*, const WCHAR*, int, void*, void*, void*, void*);
typedef int (WINAPI* GdipSaveImageToFileFunc)(void*, const WCHAR*, void*, void*);
typedef int (WINAPI* GdipDeleteGraphicsFunc)(void*);
typedef int (WINAPI* GdipDeleteFontFunc)(void*);
typedef int (WINAPI* GdipDeleteBrushFunc)(void*);
typedef int (WINAPI* GdipDeleteBitmapFunc)(void*);
typedef int (WINAPI* GdipRotateWorldTransformFunc)(void*, float, int);
typedef int (WINAPI* GdipTranslateWorldTransformFunc)(void*, float, float, int);int main() {HMODULE hGdiplus = LoadLibrary(L"gdiplus.dll");if (!hGdiplus) return 1;// 获取函数地址GdiplusStartupFunc GdiplusStartup = (GdiplusStartupFunc)GetProcAddress(hGdiplus, "GdiplusStartup");GdiplusShutdownFunc GdiplusShutdown = (GdiplusShutdownFunc)GetProcAddress(hGdiplus, "GdiplusShutdown");GdipCreateBitmapFromScan0Func GdipCreateBitmapFromScan0 = (GdipCreateBitmapFromScan0Func)GetProcAddress(hGdiplus, "GdipCreateBitmapFromScan0");GdipGetImageGraphicsContextFunc GdipGetImageGraphicsContext = (GdipGetImageGraphicsContextFunc)GetProcAddress(hGdiplus, "GdipGetImageGraphicsContext");GdipGraphicsClearFunc GdipGraphicsClear = (GdipGraphicsClearFunc)GetProcAddress(hGdiplus, "GdipGraphicsClear");GdipCreateFontFunc GdipCreateFont = (GdipCreateFontFunc)GetProcAddress(hGdiplus, "GdipCreateFont");GdipCreateSolidFillFunc GdipCreateSolidFill = (GdipCreateSolidFillFunc)GetProcAddress(hGdiplus, "GdipCreateSolidFill");GdipSetTextRenderingHintFunc GdipSetTextRenderingHint = (GdipSetTextRenderingHintFunc)GetProcAddress(hGdiplus, "GdipSetTextRenderingHint");GdipDrawStringFunc GdipDrawString = (GdipDrawStringFunc)GetProcAddress(hGdiplus, "GdipDrawString");GdipSaveImageToFileFunc GdipSaveImageToFile = (GdipSaveImageToFileFunc)GetProcAddress(hGdiplus, "GdipSaveImageToFile");GdipDeleteGraphicsFunc GdipDeleteGraphics = (GdipDeleteGraphicsFunc)GetProcAddress(hGdiplus, "GdipDeleteGraphics");GdipDeleteFontFunc GdipDeleteFont = (GdipDeleteFontFunc)GetProcAddress(hGdiplus, "GdipDeleteFont");GdipDeleteBrushFunc GdipDeleteBrush = (GdipDeleteBrushFunc)GetProcAddress(hGdiplus, "GdipDeleteBrush");GdipDeleteBitmapFunc GdipDeleteBitmap = (GdipDeleteBitmapFunc)GetProcAddress(hGdiplus, "GdipDeleteBitmap");GdipRotateWorldTransformFunc GdipRotateWorldTransform = (GdipRotateWorldTransformFunc)GetProcAddress(hGdiplus, "GdipRotateWorldTransform");GdipTranslateWorldTransformFunc GdipTranslateWorldTransform = (GdipTranslateWorldTransformFunc)GetProcAddress(hGdiplus, "GdipTranslateWorldTransform");// 初始化GDI+GdiplusStartupInput gdiplusStartupInput = {1};ULONG_PTR gdiplusToken;GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);// 创建位图(400x200 ARGB格式)void* bitmap;GdipCreateBitmapFromScan0(400, 200, 0, 0x26200A, NULL, &bitmap);// 获取图形上下文void* graphics;GdipGetImageGraphicsContext(bitmap, &graphics);// 设置白色背景GdipGraphicsClear(graphics, 0xFFFFFFFF);// 创建字体和画刷void* font;GdipCreateFont(L"Arial", 24, 0, 0, &font);void* brush;GdipCreateSolidFill(0xFF000000, &brush);// 设置文本渲染质量GdipSetTextRenderingHint(graphics, 4); // AntiAliasGridFit// 旋转30度并绘制文本GdipTranslateWorldTransform(graphics, 100, 50, 0);GdipRotateWorldTransform(graphics, 30.0f, 0);GdipDrawString(graphics, L"helloworld", -1, font, NULL, brush, NULL);// 保存为PNGCLSID pngClsid = {0x557cf406, 0x1a04, 0x11d3, {0x9a, 0x73, 0x00, 0x00, 0xf8, 0x1e, 0xf3, 0x2e}};GdipSaveImageToFile(bitmap, L"output.png", &pngClsid, NULL);// 释放资源GdipDeleteGraphics(graphics);GdipDeleteFont(font);GdipDeleteBrush(brush);GdipDeleteBitmap(bitmap);GdiplusShutdown(gdiplusToken);FreeLibrary(hGdiplus);return 0;
}

以上是直接调用gdiplus.dll实现PNG创建与旋转文本的纯API方案，基于用户历史需求(C++实现)进行扩展：

核心实现原理

通过LoadLibrary/GetProcAddress动态加载gdiplus.dll，手动声明所有必需的函数原型和结构体，完全绕过GDI+头文件依赖。关键步骤包括：

动态加载gdiplus.dll并获取函数地址
手动定义GDI+所需的结构体(如GdiplusStartupInput)
通过函数指针调用GDI+接口

关键实现要点

‌动态加载机制‌：通过LoadLibrary/GetProcAddress实现运行时绑定，避免静态链接
‌结构体手动定义‌：完全重现GdiplusStartupInput等核心结构体
‌PNG编码器CLSID‌：硬编码PNG编码器的类标识符(0x557cf406...)避免额外查询
‌资源管理‌：严格遵循创建/销毁配对原则，防止内存泄漏
‌坐标系变换‌：通过Translate/Rotate组合实现精确的文本旋转定位

对比原GDI+库方案

特性	纯API方案	GDI+库方案
依赖项	仅需gdiplus.dll	需要gdiplus.lib和头文件
初始化	手动定义所有结构体	自动包含预定义结构体
函数调用	通过函数指针间接调用	直接方法调用
代码量	显著增加(需声明所有接口)	简洁
灵活性	可选择性加载所需函数	必须链接完整库
维护性	需自行跟踪接口变更	微软官方维护