js rgb-16進制 相互轉換

//十六進制顏色值域RGB格式顏色值之間的相互轉換

//-------------------------------------
//十六進制顏色值的正則表達式
var reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f]{6})$/;
/*RGB顏色轉換為16進制*/
String.prototype.colorHex = function(){
var that = this;
if(/^(rgb|RGB)/.test(that)){
var aColor = that.replace(/(?:\(|\)|rgb|RGB)*/g,"").split(",");
var strHex = "#";
for(var i=0; i<aColor.length; i++){
var hex = Number(aColor[i]).toString(16);
if(hex === "0"){
hex += hex;
}
strHex += hex;
}
if(strHex.length !== 7){
strHex = that;
}
return strHex;
}else if(reg.test(that)){
var aNum = that.replace(/#/,"").split("");
if(aNum.length === 6){
return that;
}else if(aNum.length === 3){
var numHex = "#";
for(var i=0; i<aNum.length; i+=1){
numHex += (aNum[i]+aNum[i]);
}
return numHex;
}
}else{
return that;
}
};

//-------------------------------------------------

/*16進制顏色轉為RGB格式*/
String.prototype.colorRgb = function(){
var sColor = this.toLowerCase();
if(sColor && reg.test(sColor)){
if(sColor.length === 4){
var sColorNew = "#";
for(var i=1; i<4; i+=1){
sColorNew += sColor.slice(i,i+1).concat(sColor.slice(i,i+1));
}
sColor = sColorNew;
}
//處理六位的顏色值
var sColorChange = [];
for(var i=1; i<7; i+=2){
sColorChange.push(parseInt("0x"+sColor.slice(i,i+2)));
}
return "RGB(" + sColorChange.join(",") + ")";
}else{
return sColor;
}
}

 

********************

調用方法

var sRgb = "RGB(255, 255, 255)" , sHex = "#00538b";
var sHexColor = sRgb.colorHex();//轉換為十六進制方法
var sRgbColor = sHex.colorRgb();//轉為RGB顏色值的方法