这是一段使用 scrollPathIntoView 方法的简单的代码片段。
HTML
<canvas id="canvas"></canvas>
JavaScript
const canvas = document.getElementById("canvas");
const ctx = canvas.getContext("2d");
ctx.beginPath();
ctx.fillRect(10, 10, 30, 30);
ctx.scrollPathIntoView();
可编辑示例
修改下面的代码并在线查看 canvas 的变化：
<canvas id="canvas" width="400" height="200" class="playable-canvas">
<input id="button" type="range" min="1" max="12" />
</canvas>
<div class="playable-buttons">
<input id="edit" type="button" value="Edit" />
<input id="reset" type="button" value="Reset" />
</div>
<textarea id="code" class="playable-code">
ctx.beginPath();
ctx.rect(10, 10, 30, 30);
ctx.fill();
if (ctx.scrollPathIntoView) {
ctx.scrollPathIntoView();
} else {
ctx.fillText("Your browser does not support 'scrollPathIntoView()'.", 0, 150);
}
</textarea>
const canvas = document.getElementById("canvas");
const ctx = canvas.getContext("2d");
const textarea = document.getElementById("code");
const reset = document.getElementById("reset");
const edit = document.getElementById("edit");
const code = textarea.value;
function drawCanvas() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
eval(textarea.value);
}
reset.addEventListener("click", () => {
textarea.value = code;
drawCanvas();
});
edit.addEventListener("click", () => {
textarea.focus();
});
textarea.addEventListener("input", drawCanvas);
window.addEventListener("load", drawCanvas);