c语言代码怎么显示图片和文字

在C语言中，显示图片和文字是较为复杂的任务。因为C语言本身并不直接支持图形处理和界面生成。因此，我们通常借助于第三方图形库来完成这些任务。例如，使用常见的SDL（Simple DirectMedia Layer）库，或者在Windows平台上利用WinAPI来实现图形界面的呈现。本文将分别介绍如何使用SDL库和WinAPI来显示图片和文字。

使用SDL库显示图片和文字

安装SDL库

首先，你需要在你的系统上安装SDL库。可以通过以下步骤来安装：

# For Linux
sudo apt-get install libsdl2-dev
# For Windows
# Download the development libraries from the SDL website and follow the instructions for installation

初始化SDL

在编写代码之前，你需要初始化SDL库并创建一个窗口。以下是初始化SDL和创建窗口的示例代码：

#include 
#include 
#include 
#include 
int main(int argc, char* args[]) {
    // Initialize SDL
    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
        printf("SDL could not initialize! SDL_Error: %s\n", SDL_GetError());
        return -1;
    }
    // Create window
    SDL_Window* window = SDL_CreateWindow("SDL Tutorial", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 800, 600, SDL_WINDOW_SHOWN);
    if (window == NULL) {
        printf("Window could not be created! SDL_Error: %s\n", SDL_GetError());
        return -1;
    }
    // Create renderer
    SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
    if (renderer == NULL) {
        printf("Renderer could not be created! SDL_Error: %s\n", SDL_GetError());
        return -1;
    }
    // Initialize SDL_image
    if (!(IMG_Init(IMG_INIT_PNG) & IMG_INIT_PNG)) {
        printf("SDL_image could not initialize! IMG_Error: %s\n", IMG_GetError());
        return -1;
    }
    // Initialize SDL_ttf
    if (TTF_Init() == -1) {
        printf("SDL_ttf could not initialize! TTF_Error: %s\n", TTF_GetError());
        return -1;
    }
    // Other code here...
    // Destroy window and renderer
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    // Quit SDL subsystems
    TTF_Quit();
    IMG_Quit();
    SDL_Quit();
    return 0;
}

加载并显示图片

接下来，你需要加载图片并将其显示在窗口中。你可以使用SDL_image库来处理图片的加载。以下是加载并显示图片的示例代码：

// Load image
SDL_Surface* loadedSurface = IMG_Load("path/to/your/image.png");
if (loadedSurface == NULL) {
    printf("Unable to load image %s! SDL_image Error: %s\n", "path/to/your/image.png", IMG_GetError());
    return -1;
}
// Create texture from surface
SDL_Texture* texture = SDL_CreateTextureFromSurface(renderer, loadedSurface);
if (texture == NULL) {
    printf("Unable to create texture from %s! SDL Error: %s\n", "path/to/your/image.png", SDL_GetError());
    return -1;
}
// Free the loaded surface
SDL_FreeSurface(loadedSurface);
// Clear screen
SDL_RenderClear(renderer);
// Render texture to screen
SDL_RenderCopy(renderer, texture, NULL, NULL);
// Update screen
SDL_RenderPresent(renderer);
// Wait for a few seconds
SDL_Delay(5000);
// Destroy texture
SDL_DestroyTexture(texture);

显示文字

显示文字需要使用SDL_ttf库。你需要加载字体，创建字体纹理并将其呈现在窗口中。以下是具体代码：

// Open the font
TTF_Font* font = TTF_OpenFont("path/to/your/font.ttf", 28);
if (font == NULL) {
    printf("Failed to load font! SDL_ttf Error: %s\n", TTF_GetError());
    return -1;
}
// Render text surface
SDL_Color textColor = {255, 255, 255, 255}; // White color
SDL_Surface* textSurface = TTF_RenderText_Solid(font, "Hello, SDL!", textColor);
if (textSurface == NULL) {
    printf("Unable to render text surface! SDL_ttf Error: %s\n", TTF_GetError());
    return -1;
}
// Create texture from surface
SDL_Texture* textTexture = SDL_CreateTextureFromSurface(renderer, textSurface);
if (textTexture == NULL) {
    printf("Unable to create texture from rendered text! SDL Error: %s\n", SDL_GetError());
    return -1;
}
// Free the text surface
SDL_FreeSurface(textSurface);
// Get the dimensions of the text
int textWidth = textSurface->w;
int textHeight = textSurface->h;
// Define where to render the text
SDL_Rect renderQuad = {100, 100, textWidth, textHeight}; // Position (100, 100)
// Clear screen
SDL_RenderClear(renderer);
// Render texture to screen
SDL_RenderCopy(renderer, textTexture, NULL, &renderQuad);
// Update screen
SDL_RenderPresent(renderer);
// Wait for a few seconds
SDL_Delay(5000);
// Destroy texture and close font
SDL_DestroyTexture(textTexture);
TTF_CloseFont(font);

使用WinAPI显示图片和文字

创建窗口

WinAPI是Windows操作系统提供的一组API，用于进行图形界面编程。首先我们需要创建一个窗口：

#include 
// The main window procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
    switch (msg) {
        case WM_CLOSE:
            DestroyWindow(hwnd);
            break;
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
    // Window class structure
    WNDCLASSEX wc;
    ZeroMemory(&wc, sizeof(WNDCLASSEX));
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.lpfnWndProc = WndProc;
    wc.hInstance = hInstance;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)COLOR_WINDOW;
    wc.lpszClassName = "WindowClass";
    RegisterClassEx(&wc);
    // Create window
    HWND hwnd = CreateWindowEx(0, "WindowClass", "WinAPI Tutorial", WS_OVERLAPPEDWINDOW,
                               300, 300, 800, 600, NULL, NULL, hInstance, NULL);
    ShowWindow(hwnd, nCmdShow);
    // Main message loop
    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return msg.wParam;
}

显示图片

接下来，使用位图来显示图片。首先我们要加载位图并显示：

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
    static HBITMAP hBitmap;
    HDC hdc, hdcMem;
    PAINTSTRUCT ps;
    switch (msg) {
        case WM_CREATE:
            hBitmap = (HBITMAP)LoadImage(NULL, "path/to/your/image.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
            if (hBitmap == NULL) {
                MessageBox(hwnd, "Could not load image!", "Error", MB_OK | MB_ICONERROR);
                return -1;
            }
            break;
        case WM_PAINT:
            hdc = BeginPaint(hwnd, &ps);
            hdcMem = CreateCompatibleDC(hdc);
            SelectObject(hdcMem, hBitmap);
            BitBlt(hdc, 0, 0, 800, 600, hdcMem, 0, 0, SRCCOPY);
            DeleteDC(hdcMem);
            EndPaint(hwnd, &ps);
            break;
        case WM_CLOSE:
            DestroyWindow(hwnd);
            break;
        case WM_DESTROY:
            DeleteObject(hBitmap);
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}

显示文字

最后，我们可以使用TextOut函数来显示文字：

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
    HDC hdc;
    PAINTSTRUCT ps;
    switch (msg) {
        case WM_PAINT:
            hdc = BeginPaint(hwnd, &ps);
            TextOut(hdc, 100, 100, "Hello, WinAPI!", strlen("Hello, WinAPI!"));
            EndPaint(hwnd, &ps);
            break;
        case WM_CLOSE:
            DestroyWindow(hwnd);
            break;
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}

以上便是使用C语言显示图片和文字的方法，无论是通过SDL库还是WinAPI。通过上述的详细步骤和代码示例，相信你已经掌握了在不同平台上实现图片和文字显示的基本方法。希望这篇文章对你有所帮助。