将字符串中下划线去掉并把下划线后面的首字母改为大写 如：ba_cd_sa 改为baCdSa

splitDownLineandAfterToUpperCase(str) {

var s = str.split('_');

var newA="";

for(var i=1;i<s.length;i++){

newA += s[i].substring(0, 1).toUpperCase() + s[i].substring(1);

}

return newA =s[0]+newA;

},