Question

如果按下某个键，我的SDL2程序将忽略鼠标单击。这是我的MCVE：

#include <SDL.h>

void myEventHandler(bool& mouseClicked, bool& letsQuit)
{
    SDL_Event event;

    while (SDL_PollEvent(&event))
        switch (event.type)
        {
        case SDL_QUIT:            letsQuit = true;   break;
        case SDL_MOUSEBUTTONDOWN: mouseClicked = true;
        }
}

int main(int argc, char** argv)
{
    //Init SDL
    SDL_Window*   sldWindow;
    SDL_Renderer* sdlRenderer;

    if (SDL_Init(SDL_INIT_EVERYTHING) < 0)
        return -1;
    if (!(sldWindow   = SDL_CreateWindow("", SDL_WINDOWPOS_UNDEFINED, 
                                         SDL_WINDOWPOS_UNDEFINED,640, 480, 0))) 
        return -1;
    if (!(sdlRenderer = SDL_CreateRenderer(sldWindow, -1, 0))) 
        return -1;
    SDL_ClearError();

    //Initialize some conditions
    bool letsDrawRed= true;   //Draw a red square, not blue        
    bool letsQuit = false;    //Quit the program

    while (! letsQuit)
    {
        SDL_RenderPresent(sdlRenderer);

        //static int framesSinceLastMouseClick = 0; //latency
        bool       mouseClicked = false;
        myEventHandler (mouseClicked, letsQuit);

        if (letsDrawRed) SDL_SetRenderDrawColor(sdlRenderer, 255, 0, 0, 255); //draw square as red
        else             SDL_SetRenderDrawColor(sdlRenderer, 0, 0, 255, 255); //else draw it blue

        static SDL_Rect rect = { 0, 0, 100, 100 }; //draw the square
        SDL_RenderFillRect(sdlRenderer, &rect);

        //if clicked, and enough time since last click...
        //(All of these commented-out conditions fail too)
        //if (framesSinceLastMouseClick > 600 && mouseClicked) 
        //if (framesSinceLastMouseClick > 600 && SDL_GetMouseState(NULL, NULL))
        //if (mouseClicked)
        if (SDL_GetMouseState(NULL,NULL))
        {
            //framesSinceLastMouseClick = 0;  
            letsDrawRed = !letsDrawRed;
        }
        //else ++framesSinceLastMouseClick;
    }

    SDL_DestroyWindow(sldWindow); 
    SDL_Quit();

    return 0;
}

我在评论中留下了一些东西，以证明它们不是问题。一种是等待时间条件（framesSinceLastMouseClick）。另一个是从SDL_PollEvent获取鼠标事件，而不是调用SDL_GetMouseState。）

要注意的另一件事是这仅在按下的键可打印时才是问题。 CapsLock，Shift，Alt，Ctrl和Function键不会造成问题。

平台是MS Windows上的Visual Studio。

那么...在按下某个键时，如何才能找到那只鼠标？在真实游戏中这将是一个问题！

Answer 1

这不是SDL，而是我所在的计算机，当按下可打印字符时，它无法从鼠标（实际上是触控板）发送信息。显然，从键盘发送多个信号是一个长期存在的问题，结果是“键盘重影”（某些键-在我的情况下是触控板的点击-丢失了）。

发布时，我能够检查键盘/触控板可以在https://keyboardtester.co/mouse-click-tester.html发送的输出。

按下键时SDL2无法获得鼠标输入

1 个答案: