Question

当我尝试使用HTML5 Canvas drawImage并将页面从Canvas页面更改为另一个页面时，我在React中遇到此错误：

TypeError：无法在'CanvasRenderingContext2D'上执行'drawImage'：提供的值不是'（CSSImageValue或HTMLImageElement或SVGImageElement或HTMLVideoElement或HTMLCanvasElement或ImageBitmap或OffscreenCanvas）'

这是错误https://www.useloom.com/share/3c233254114a45c2933068cc2324c579

在这种情况下怎么了？谢谢！

Answer 1

我找到了解决方案，有必要检查是否有图像，并在有图像的情况下调用drawImage（）。这是我的代码

import org.apache.commons.beanutils.*;
import org.apache.commons.beanutils.converters.DateConverter;

import java.util.Date;

public class Main {

    public static void main(String[] args) throws Exception {
        DateConverter converter = new DateConverter();
        converter.setPattern("yyyy-MM-dd");

        ConvertUtilsBean convertUtilsBean = new ConvertUtilsBean();
        convertUtilsBean.register(converter, Date.class);

        BeanUtilsBean beanUtilsBean = new BeanUtilsBean(convertUtilsBean, new PropertyUtilsBean());

        UserDto dto = new UserDto("42", "2018-11-14");
        System.out.println("dto.getUserId() = " + dto.getUserId());
        System.out.println("dto.getDob() = " + dto.getDob());

        UserModel model = new UserModel();
        beanUtilsBean.copyProperties(model, dto);

        System.out.println("model.getUserId() = " + model.getUserId());
        System.out.println("model.getDob() = " + model.getDob());
    }

}

React组件中有以下错误：无法在'CanvasRenderingContext2D'

1 个答案: