js 二进制 base64编码

// 将二进制数据转换为 Base64 编码
function arrayBufferToBase64(buffer) {
    let binary = '';
    const bytes = new Uint8Array(buffer);
    const len = bytes.byteLength;
    for (let i = 0; i < len; i++) {
        binary += String.fromCharCode(bytes[i]);
    }
    return btoa(binary);
}

// 将 Base64 编码转换为二进制数据
function base64ToArrayBuffer(base64) {
    const binary_string = atob(base64);
    const len = binary_string.length;
    const bytes = new Uint8Array(len);
    for (let i = 0; i < len; i++) {
        bytes[i] = binary_string.charCodeAt(i);
    }
    return bytes.buffer;
}

// 示例：读取图片文件并转换为 Base64 编码
const input = document.createElement('input');
input.type = 'file';
input.onchange = function(event) {
    const file = event.target.files[0];
    const reader = new FileReader();
    reader.onload = function(e) {
        const base64 = arrayBufferToBase64(e.target.result);
        console.log('Base64 编码:', base64);
    };
    reader.readAsArrayBuffer(file);
};
document.body.appendChild(input);