帮助理解以下代码？ [英] Help in understanding the following code?

问题描述

我试图将鼠标位置存储在矢量中，然后调用矢量元素来显示我的点数。我偶然发现了stackoverflow.com中的这个帖子（ http://stackoverflow.com/questions/24586013/opencv-storing-the-coordinates-of-the-points-clicked-by-mouse-left-button [ ^ ]





我无法理解以下代码行，如果有人能解释代码的含义，我将非常感激。

I was trying to store my mouse positions in a vector and then call the vector elements to display my points. I stumbled upon this thread in stackoverflow.com (http://stackoverflow.com/questions/24586013/opencv-storing-the-coordinates-of-the-points-clicked-by-mouse-left-button[^]


I couldn't understand the following lines of code and would really appreciate if someone can explain me the meaning of the code.

void onMouse(int evt, int x, int y, int flags, void* param) {
    if(evt == CV_EVENT_LBUTTONDOWN) {
        std::vector<cv::Point>* ptPtr = (std::vector<cv::Point>*)param;  // Especially this line
        ptPtr->push_back(cv::Point(x,y));
    }
}

[您的代码已损坏，因此我将其修复为原始版本]

[Your code was corrupted, so I fixed it back to the original]

推荐答案

基本上这行发生了什么

Basically what happens in this line

std::vector<cv::point xmlns:cv="#unknown">* ptPtr = (std::vector<cv::point>*)param;</cv::point></cv::point>

是输入参数 param 被类型转换为类型的指针std :: vector< cv :: Point>

然后将坐标（x，y）添加到数组/向量中。



在这里，您可以阅读有关 std :: vector 的更多信息[ ^ ]

is that the input argument param is being type cast into a pointer of type std::vector<cv::Point>
Then the coordinates (x,y) is added to the array/vector.

Here you can read more about std::vector[^]

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