纯Javascript-函数生成的onclick元素的变化class

Question

我是编码方面的新手，几天来一直在解决一个问题，但没有找到解决方案。我正在尝试使用由正方形组成的网格构建一个 canvas，当单击正方形时，它会更改其背景颜色。我正在学习纯 javascript，我的问题是我无法找到一种方法来引用单击的元素并仅更改其 class，因为我的网格是由函数生成的。我这样做是因为我希望将来能够更改 canvas 大小。关于如何进行的任何建议？

HTML

<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Square Canvas Game</title>
    <link rel="stylesheet" href="style.css">
    <link href="https://fonts.googleapis.com/css2?family=Merriweather:ital,wght@0,300;0,400;0,700;0,900;1,300;1,400;1,700;1,900&display=swap" rel="stylesheet">
</head>
<body onload="javascript:setInitialCanvas()">
    <header>
        <h1>Square artist</h1>
    </header>
    <div id="gameInterfaceContainer">
        <button id="clearCanvas" onclick="clearAllSquares()">Clear All</button>
    
        <div id="canvas">
        </div>
    </div>
    <script src="script.js"></script>
</body>
</html>

JS

function setInitialCanvas(){
    for (let i =0; i<400; i++){
        let initialSquare = document.createElement("div");
        document.getElementById("canvas").appendChild(initialSquare);
        initialSquare.className = "canvasSquare clearSquare";
        initialSquare.onclick = changeSquareColor(this);
        initialSquare.style.backgroundColor = "white";
        initialSquare.id = "square" + i;
    }
}
function changeSquareColor(this){
    let squareColor = ["white","blue","black","green","red","yellow","gray","brown"];
    let colorIndex = 0;

    while (squareColor[colorIndex] != this.style.backgroundColor){
        colorIndex += 1;
    }
    if(this.style.backgroundColor == squareColor[squareColor.length]){
        this.style.backgroundColor = squareColor[0];
    }else
    colorIndex += 1;
    this.style.backgroundColor = squareColor[colorIndex];

}

谢谢！

*编辑：添加代码笔（不起作用）https://codepen.io/ccue92/pen/qBNKLQY

Answer 1

它不起作用的原因是您没有将 changeSquareColor 函数绑定到 onclick 事件，而是绑定了它的结果。

您需要像这样更改 onclick 绑定：

initialSquare.onclick = function(event) {
    changeSquareColor(event.target);
}

并且不要使用“this”作为变量名，因为它是当前作用域的保留字：

function changeSquareColor(square) {
    let squareColor = ["white","blue","black","green","red","yellow","gray","brown"];
    let colorIndex = 0;

    while (squareColor[colorIndex] != square.style.backgroundColor){
        colorIndex += 1;
    }
    if(square.style.backgroundColor == squareColor[squareColor.length]){
        square.style.backgroundColor = squareColor[0];
    } else {
        colorIndex += 1;
    }
    square.style.backgroundColor = squareColor[colorIndex];
}

纯Javascript-函数生成的onclick元素的变化class

Pure Javascript- Change class of onclick element generated by function

javascript

onclick

this