substringByStr method
截取2个字符串之间的字符串
Implementation
String substringByStr(String start, String end) {
if (this.isEmptyString) {
return '';
}
int startIndex = this?.indexOf(start) ?? 0;
int endIndex = this?.indexOf(end, startIndex + start.length) ?? 0;
return this?.substring(startIndex + start.length, endIndex) ?? "";
}