javascript - 在参数列表后缺少 )，即使我在指定位置添加了 )

Question

在浏览器中查看我的网页时，我在以下功能上收到此控制台错误。

function drawStartButton(){
            image.onload = function(){
                context.drawImage(image, 260.5, 60);
                image.on("mousdown", function(){
                    drawLevelOneElements();
                }
            });
            image.src = "StartButton.png";
            /** Now I need to add an event listener to the area of the canvas on 
                on which the button image is displayed, in order to 'listen' for 
                a click on the button */
            var boundingBox = myGameCanvas.getBoundingClientRect();
            //var mouseX = (mouse_event.clientX-boundingBox.left) * (myGameCanvas.width/boundingBox.width);
            //var mouseY = (mouse_event.clientY-boundingBox.top) * (myGameCanvas.height/boundingBox.height);
            boundingBox.onmousemove = function(e){
                var mouseX = e.pageX - this.offsetLeft;
                var mouseY = e.pageY - this.offsetTop;
                var pixels = context.getImageData(mouseX, mouseY, 1, 1);
            }

            /** There maybe more than one pixel at this location so use a loop
                to test whether any of the pixels have an alpha value greater than
                0. With pixel data, 3 is alpha, so check data[3] and every fourth
                element in data after that. */
            //for (var i=3; i<pixels.data.length; i+=4;){
                /** If a non- zero alpha is found, stop and return "true"- the click
                    was on a part of the canvas that has colour on it. */
            //  if(pixels.data[i]!=0) return true;
            //}

            /** If the function gets here, then the mouse click wasn't on a painted
                part of the canvas. */
            //return false;
            /**myGameCanvas.getElementById("StartButton").onClick = function(e){
                drawLevelOneElements();
            } */    

        }

错误发生在从第二行开始的函数末尾。最初，我的那一行只是 }; 但在收到此错误后，我将其更改为 });

但是，当我重新加载页面时， Canvas 仍然是空白的，并且控制台提示同样的错误，即使我已经在指示的位置插入了 )。

我查看了针对此错误的一些建议主题，但似乎没有一个主题表明我需要做什么才能使函数在 Canvas 上显示它们的含义。有人有什么建议吗？

Answer 1

image.onload = function(){
    context.drawImage(image, 260.5, 60);
    image.on("mousdown", function(){
        drawLevelOneElements();
    }
});

需要:

image.onload = function(){
    context.drawImage(image, 260.5, 60);
    image.on("mousdown", function(){
        drawLevelOneElements();
    });
};

注意最后的)