我要使用js实现这个PHP签名函数，不使用第三方库，纯js实现且参数及值要urlencode下，public function generateSignature($data, $secretKey) { unset($data['sign']); // Sort the data by key ksort($data); // Convert the data to a query string $queryString = http_build_query($data); // Add the secret key to the query string $queryString .= $secretKey; // Generate the signature using the SHA256 algorithm $signature = hash('sha256', $queryString); // Return the signature return $signature; }

可以参考以下代码实现：

function generateSignature(data, secretKey) {
  delete data['sign'];
  var sortedData = {};
  Object.keys(data).sort().forEach(function(key) {
    sortedData[key] = data[key];
  });
  var queryString = Object.keys(sortedData).map(function(key) {
    return encodeURIComponent(key) + '=' + encodeURIComponent(sortedData[key]);
  }).join('&');
  queryString += secretKey;
  var signature = sha256(queryString);
  return signature;
}

其中，`sha256` 函数可以使用 CryptoJS 库实现。如果不想使用 CryptoJS，你可以参考以下代码实现：

function sha256(str) {
  var utf8Str = new TextEncoder().encode(str);
  return crypto.subtle.digest('SHA-256', utf8Str).then(function(hash) {
    return hex(hash);
  });
}

function hex(buffer) {
  var hexCodes = [];
  var view = new DataView(buffer);
  for (var i = 0; i < view.byteLength; i += 4) {
    var value = view.getUint32(i);
    var stringValue = value.toString(16);
    var padding = '00000000';
    var paddedValue = (padding + stringValue).slice(-padding.length);
    hexCodes.push(paddedValue);
  }
  return hexCodes.join('');
}

注意，这里使用了 `TextEncoder` 和 `crypto.subtle.digest` API，所以需要在支持这些 API 的浏览器中运行。如果需要在不支持这些 API 的浏览器中运行，你可以使用以下代码实现：

function sha256(str) {
  var sha256Hash = sha256_digest(str);
  var hexCodes = [];
  for (var i = 0; i < sha256Hash.length; i++) {
    var hexCode = sha256Hash[i].toString(16);
    var paddedHexCode = ('00' + hexCode).slice(-2);
    hexCodes.push(paddedHexCode);
  }
  return hexCodes.join('');
}

function sha256_digest(str) {
  var utf8Str = unescape(encodeURIComponent(str));
  var bytes = new Uint8Array(utf8Str.length);
  for (var i = 0; i < utf8Str.length; i++) {
    bytes[i] = utf8Str.charCodeAt(i);
  }
  return sha256_digest_bytes(bytes);
}

function sha256_digest_bytes(bytes) {
  var blockSize = 64;
  var hashSize = 32;
  var messageLength = bytes.length;
  var paddingSize = blockSize - ((messageLength + 9) % blockSize) - 1;
  var paddedMessageLength = messageLength + paddingSize + 9;
  var paddedMessage = new Uint8Array(paddedMessageLength);
  paddedMessage.set(bytes);
  paddedMessage.set([0x80], messageLength);
  for (var i = messageLength + 1; i < paddedMessageLength - 8; i++) {
    paddedMessage[i] = 0;
  }
  var bitLength = messageLength * 8;
  var bitLengthBytes = new Uint8Array(8);
  bitLengthBytes[0] = (bitLength >>> 56) & 0xff;
  bitLengthBytes[1] = (bitLength >>> 48) & 0xff;
  bitLengthBytes[2] = (bitLength >>> 40) & 0xff;
  bitLengthBytes[3] = (bitLength >>> 32) & 0xff;
  bitLengthBytes[4] = (bitLength >>> 24) & 0xff;
  bitLengthBytes[5] = (bitLength >>> 16) & 0xff;
  bitLengthBytes[6] = (bitLength >>> 8) & 0xff;
  bitLengthBytes[7] = bitLength & 0xff;
  paddedMessage.set(bitLengthBytes, paddedMessageLength - 8);
  var hash = sha256_compress(paddedMessage);
  var hashBytes = new Uint8Array(hashSize);
  for (var i = 0; i < hashSize; i++) {
    hashBytes[i] = (hash[i >>> 2] >>> (24 - (i % 4) * 8)) & 0xff;
  }
  return hashBytes;
}

function sha256_compress(paddedMessage) {
  var blockSize = 64;
  var hashSize = 32;
  var k = new Uint32Array([
    0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
    0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
    0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
    0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
    0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
    0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
    0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
    0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
    0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
    0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
    0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
    0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
    0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
    0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
    0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
  ]);
  var h = new Uint32Array([
    0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
    0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
  ]);
  var w = new Uint32Array(blockSize);
  for (var i = 0; i < paddedMessage.length; i += blockSize) {
    for (var j = 0; j < blockSize; j++) {
      w[j] = (j < 16) ? paddedMessage[i + j] :
        sha256_sigma1(w[j - 2]) + w[j - 7] + sha256_sigma0(w[j - 15]) + w[j - 16];
    }
    var a = h[0];
    var b = h[1];
    var c = h[2];
    var d = h[3];
    var e = h[4];
    var f = h[5];
    var g = h[6];
    var h0 = h[7];
    for (var j = 0; j < blockSize; j++) {
      var t1 = h0 + sha256_sigma1(e) + sha256_ch(e, f, g) + k[j] + w[j];
      var t2 = sha256_sigma0(a) + sha256_maj(a, b, c);
      h0 = g;
      g = f;
      f = e;
      e = d + t1;
      d = c;
      c = b;
      b = a;
      a = t1 + t2;
    }
    h[0] += a;
    h[1] += b;
    h[2] += c;
    h[3] += d;
    h[4] += e;
    h[5] += f;
    h[6] += g;
    h[7] += h0;
  }
  return h.buffer;
}

function sha256_ch(x, y, z) {
  return (x & y) ^ (~x & z);
}

function sha256_maj(x, y, z) {
  return (x & y) ^ (x & z) ^ (y & z);
}

function sha256_sigma0(x) {
  return sha256_rotr(2, x) ^ sha256_rotr(13, x) ^ sha256_rotr(22, x);
}

function sha256_sigma1(x) {
  return sha256_rotr(6, x) ^ sha256_rotr(11, x) ^ sha256_rotr(25, x);
}

function sha256_rotr(n, x) {
  return (x >>> n) | (x << (32 - n));
}

这里实现了 SHA256 算法的压缩函数和常用函数，以及一个 `sha256_digest` 函数和一个 `sha256` 函数，用于计算 SHA256 哈希值。注意，这里的 `sha256` 函数和 CryptoJS 库中的 `sha256` 函数返回的结果格式不同，需要根据具体情况进行调整。