无法将图表保存为图像

Question

我已经编写了一个将图表保存为图像的功能。我已经提到了我编写的代码： HTML：

Uncaught TypeError: Failed to execute 'drawImage' on 'CanvasRenderingContext2D': The provided value is not of type '(CSSImageValue or HTMLImageElement or SVGImageElement or HTMLVideoElement or HTMLCanvasElement or ImageBitmap or OffscreenCanvas)'
    at saveChart1 (generatedContent:310)
    at HTMLSpanElement.onclick

Javescript：

public void floodFill(Bitmap bitmap, Point point, int i, int j) {
int k = bitmap.getWidth();
int l = bitmap.getHeight();
if (i != j) {
    LinkedList linkedlist = new LinkedList();
    do {
        int i1 = point.x;
        int j1;
        for (j1 = point.y; i1 > 0 && !isBlack(bitmap.getPixel(i1 - 1, j1),j); i1--) {
        }
        boolean flag = false;
        boolean flag1 = false;
        while (i1 < k && !isBlack(bitmap.getPixel(i1, j1), j)) {
            bitmap.setPixel(i1, j1, j); //main

            if (!flag && !isBlack(bitmap.getPixel(i1, j1 - 1), j)) {
                linkedlist.add(new Point(i1, j1 - 1));
                flag = true;
            } else if (flag && isBlack(bitmap.getPixel(i1, j1 - 1), j)) {
                flag = false;
            }

            if (!flag1 && !isBlack(bitmap.getPixel(i1, j1 + 1), j)) {
                linkedlist.add(new Point(i1, j1 + 1));
                flag1 = true;
            } else if (flag1 && j1 < l - 1 && isBlack(bitmap.getPixel(i1, j1 + 1), j)) {
                flag1 = false;
            }
            i1++;
        }

        point = (Point) linkedlist.poll();
    } while (point != null);
}

// maybe even reorder the conditions:
// If conditions are equal hard to compute:
// for || always do the mostlikely satisfied condition to the front
// for && always do the mostlikely to fail condition to the front



private boolean isBlack(int i, int j) {
    float r= Color.red(i);
    float g= Color.green(i);
    float b= Color.blue(i);
    retrun (r == g && g == b && r < 100 || i == j) ;
}

当我点击保存按钮然后得到以下提到的错误：

e.getCause().getMessage()

任何人都可以建议我在哪里做错了。

Answer 1

试试这个

DELETE

Working example