最近在做一個藍牙app的項目,其中有用到使用藍牙與裝置進行資料互動傳輸的過程,使用的都是16進制數協定,對于我們做java開發的或者html,js的程式員來講是有點暈的,下面貼出使用js将16進制與浮點數進行轉換的js代碼:
//需要用到的函數
function InsertString(t, c, n) {
var r = new Array();
for (var i = 0; i * 2 < t.length; i++) {
r.push(t.substr(i * 2, n));
}
return r.join(c);
}
//需要用到的函數
function FillString(t, c, n, b) {
if ((t == "") || (c.length != 1) || (n <= t.length)) {
return t;
}
var l = t.length;
for (var i = 0; i < n - l; i++) {
if (b == true) {
t = c + t;
}
else {
t += c;
}
}
return t;
}
//16進制轉浮點數
function HexToSingle(t) {
t = t.replace(/\s+/g, "");
if (t == "") {
return "";
}
if (t == "00000000") {
return "0";
}
if ((t.length > 8) || (isNaN(parseInt(t, 16)))) {
return "Error";
}
if (t.length < 8) {
t = FillString(t, "0", 8, true);
}
t = parseInt(t, 16).toString(2);
t = FillString(t, "0", 32, true);
var s = t.substring(0, 1);
var e = t.substring(1, 9);
var m = t.substring(9);
e = parseInt(e, 2) - 127;
m = "1" + m;
if (e >= 0) {
m = m.substr(0, e + 1) + "." + m.substring(e + 1)
}
else {
m = "0." + FillString(m, "0", m.length - e - 1, true)
}
if (m.indexOf(".") == -1) {
m = m + ".0";
}
var a = m.split(".");
var mi = parseInt(a[0], 2);
var mf = 0;
for (var i = 0; i < a[1].length; i++) {
mf += parseFloat(a[1].charAt(i)) * Math.pow(2, -(i + 1));
}
m = parseInt(mi) + parseFloat(mf);
if (s == 1) {
m = 0 - m;
}
return m;
}
//浮點數轉16進制
function SingleToHex(t) {
if (t == "") {
return "";
}
t = parseFloat(t);
if (isNaN(t) == true) {
return "Error";
}
if (t == 0) {
return "00000000";
}
var s,
e,
m;
if (t > 0) {
s = 0;
}
else {
s = 1;
t = 0 - t;
}
m = t.toString(2);
if (m >= 1) {
if (m.indexOf(".") == -1) {
m = m + ".0";
}
e = m.indexOf(".") - 1;
}
else {
e = 1 - m.indexOf("1");
}
if (e >= 0) {
m = m.replace(".", "");
}
else {
m = m.substring(m.indexOf("1"));
}
if (m.length > 24) {
m = m.substr(0, 24);
}
else {
m = FillString(m, "0", 24, false)
}
m = m.substring(1);
e = (e + 127).toString(2);
e = FillString(e, "0", 8, true);
var r = parseInt(s + e + m, 2).toString(16);
r = FillString(r, "0", 8, true);
return InsertString(r, " ", 2).toUpperCase();
}