Question

我有#include <opencv2\opencv.hpp> int main() { cv::Mat3b star = cv::imread("path/to/image"); cv::imshow("Original", star); cv::Mat3b hsv; cv::cvtColor(star, hsv, cv::COLOR_BGR2HSV); cv::Mat1b mask; cv::inRange(hsv, cv::Scalar(29, 220, 220), cv::Scalar(30, 255, 255), mask); cv::imshow("mask", mask); // Change to 'false' to see how to use the 'cv::mask' approach if (true) { double blue, green, red = 0.0; int counter = 0; for (int r = 0; r < star.rows; r++) { for (int c = 0; c < star.cols; c++) { if (mask(r, c) > 0) { ++counter; blue += star(r, c)[0]; green += star(r, c)[1]; red += star(r, c)[2]; } } } // Avoid division by 0 if (counter > 0) { blue /= counter; green /= counter; red /= counter; } std::cout << "$$ Red(R), Green(G), Blue(B) $$" << " \n\n"; std::cout << "avg_R: " << red << " \n"; std::cout << "avg_G: " << green << " \n"; std::cout << "avg_B: " << blue << " \n\n"; } else { cv::Scalar mean_value = cv::mean(star, mask); double blue = mean_value[0]; double green = mean_value[1]; double red = mean_value[2]; std::cout << "$$ Red(R), Green(G), Blue(B) $$" << " \n\n"; std::cout << "avg_R: " << red << " \n"; // red value std::cout << "avg_G: " << green << " \n"; // green value std::cout << "avg_B: " << blue << " \n\n"; // blue value } cv::waitKey(); }函数，目的是选择该值是否在数组内已经存在。如果不存在，此函数会将值输入到updateLocation中，然后将其放在array上，反之亦然。

但是当我尝试单击它时，出现了这样的错误：

未捕获的TypeError：无法读取未定义的属性“ includes”

这是我写的代码：

state

我认为这个错误实际上是没有意义的，因为以前有一个功能几乎相同，但是可以正常工作。

updateLocation(e) {
    let locationArray = this.state.checked.location;
    let value         = parseInt(e.target.value);
    //v this is the error comes from v
    if (locationArray.includes(value)) {
      locationArray.splice(locationArray.indexOf(value), 1);
    } else {
      locationArray.push(value)
    }
    this.setState({
      checked: {
        location: locationArray
      }
    })
}

状态

updateCategory(e) {
    let categoryArray = this.state.checked.categories;
    let value         = parseInt(e.target.value);
    //this one works fine even It looks the same like updateLocation()
    if (categoryArray.includes(value)) {
      categoryArray.splice(categoryArray.indexOf(value), 1);
    } else {
      categoryArray.push(value)
    }
    this.setState({
      checked: {
        categories: categoryArray
      }
    })
  }

constructor(props) { super(props); this.state = { jobs : [], category: [], location: [], loading : true, count : 8, checked : { categories: [], location : [] } } }函数位于更新updateCategory上方

这是称为updateLocation的代码

updateLocation

更新：

我尝试<div className="card-body"> {state.location.map((item, i) => ( <div className="checkbox" key={i}> <input type="checkbox" value={item.id} onChange={e => this.updateLocation(e)} checked={state.checked.categories.includes(item.id)}/> {item.city_name} </div> )} <a onClick={e => this.viewAllLocation(e)} id="view-all-loc">View more >>></a> <div id="show-loading-loc" style={{display: 'none'}}>Loading...</div> </div>，但奇怪的是，没有出现错误，只是控制台中console.log(locationArray.includes(value))的结果是locationArray.includes(value)

Javascript-两个相同的功能，但只有一个可以使用

更新：

更多更新：

1 个答案: