//函数原型
function StringReplace(const S, OldPattern, NewPattern: string; Flags: TReplaceFlags): string;
//参数说明:
//S: 源字符串
//OldPattern: 想要替换的字符串
//NewPattern: 新的字符串
//Flags: [rfReplaceAll]:全部替换 [rfIgnoreCase]:忽略大小写
//举个例子:
StringReplace ('a12324A', '2', '0', []); //a10324A
StringReplace ('a12324A', '2', '0', [rfReplaceAll]); //a10304A
StringReplace ('a12324A', 'a', '0', [rfReplaceAll, rfIgnoreCase]); //0123240