功能说明：//setlength取得字符串长度 设置字符长度
//取得字符串长度length();
procedureTForm1.btn1Click(Sender: TObject);
var
str:string;
begin
str:='abcd';
ShowMessage(IntToStr(length(str)));
end;
//设置字符长度setlength()
procedureTForm1.Button1Click(Sender: TObject);
var
mystr:string;
begin
mystr:='hello';
setlength(mystr,3);//将字符串定义为3个字节的长度
showmessage(mystr);
end;