主页 / user-697627

Maksim's questions

Martin Hope
Maksim
Asked: 2025-03-17 23:35:25 +0800 CST
  • 6

我有类似这样的代码

const canvas1 = document.getElementById('canvas-1');
const canvas2 = document.getElementById('canvas-2');

const createContext = () => {
    let ctx1, ctx2;
    if (document.querySelector('#gpu').checked) {
        console.log('gpu');
        ctx1 = canvas1.getContext('2d', { willReadFrequently: false });
        ctx2 = canvas2.getContext('2d', { willReadFrequently: false });
    } else {
        console.log('cpu');
        ctx1 = canvas1.getContext('2d', { willReadFrequently: true });
        ctx2 = canvas2.getContext('2d', { willReadFrequently: true });
    }

    return [ctx1, ctx2];
};

let [ctx1, ctx2] = createContext();

<label for="gpu">gpu processing</label>
<input type="checkbox" id="gpu" ><br>

问题是，当调用该函数时上下文不会改变createContext()，通过调试器判断，所有步骤都已完成，但是，尽管如此，当您单击复选框时上下文不会改变。

在后台，按钮调用了几个函数，包括创建上下文。

问题是，是否有可能CanvasRenderingContext2D在开发过程中更改代码，还是一劳永逸地创建代码？第二种情况，是否可以改变willReadFrequently上下文？

javascript