js下载图片代码怎么写

function downloadImage(imageUrl, imageName) {
    const link = document.createElement('a');
    link.href = imageUrl;
    link.download = imageName;
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
}

// 使用示例
downloadImage('https://example.com/image.jpg', 'my-image.jpg');

async function downloadImage(imageUrl, imageName) {
    const response = await fetch(imageUrl);
    const blob = await response.blob();
    const link = document.createElement('a');
    link.href = URL.createObjectURL(blob);
    link.download = imageName;
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
}

// 使用示例
downloadImage('https://example.com/image.jpg', 'my-image.jpg');

function downloadImage(imageUrl, imageName) {
    const img = new Image();
    img.crossOrigin = "Anonymous";
    img.onload = function() {
        const canvas = document.createElement('canvas');
        const ctx = canvas.getContext('2d');
        canvas.width = img.width;
        canvas.height = img.height;
        ctx.drawImage(img, 0, 0);
        const link = document.createElement('a');
        link.href = canvas.toDataURL('image/jpeg');
        link.download = imageName;
        document.body.appendChild(link);
        link.click();
        document.body.removeChild(link);
    };
    img.src = imageUrl;
}

// 使用示例
downloadImage('https://example.com/image.jpg', 'my-image.jpg');

const img = new Image();
img.crossOrigin = "Anonymous";
img.src = imageUrl;

const link = document.createElement('a');
link.href = canvas.toDataURL('image/jpeg'); // 指定格式为JPEG