js image 文件大小

function checkImageSize(file) {
    return new Promise((resolve, reject) => {
        const img = new Image();
        img.src = URL.createObjectURL(file);
        img.onload = () => {
            const sizeInBytes = file.size;
            const sizeInKB = sizeInBytes / 1024;
            resolve({ width: img.width, height: img.height, sizeInBytes, sizeInKB });
        };
        img.onerror = reject;
    });
}

// 使用示例
const fileInput = document.querySelector('input[type="file"]');
fileInput.addEventListener('change', async (event) => {
    const file = event.target.files[0];
    try {
        const { width, height, sizeInBytes, sizeInKB } = await checkImageSize(file);
        console.log(`图像尺寸: ${width}x${height}, 文件大小: ${sizeInKB.toFixed(2)} KB`);
    } catch (error) {
        console.error('无法加载图像:', error);
    }
});