Delphi 中的字符串函数，5 - SysUtils 中的 Ansi 字符串函数

//对比字符串是不是一样: AnsiSameStr、AnsiSameText
var
  ss,s: AnsiString;
  b: Boolean;
begin
  ss := 'abc';
  s := 'ABC';

  b := AnsiSameStr(ss,s);    {区分大小写}
  ShowMessage(BoolToStr(b)); {False}

  b := AnsiSameText(ss,s);   {不区分大小写}
  ShowMessage(BoolToStr(b)); {True}
end;

//比较两个字符串大小: AnsiCompareStr、AnsiCompareText
var
  s1,s2: AnsiString;
  i: Integer;
begin
  s1 := 'Hello';
  s2 := 'hello';

  i := AnsiCompareStr(s1,s2);  {区分大小写}
  ShowMessage(IntToStr(i));    {1}

  i := AnsiCompareText(s1,s2); {不区分大小写}
  ShowMessage(IntToStr(i));    {0}

{有 3 种可能的返回值:
  s1 > s2 : 1
  s1 < s2 : -1
  s1 = s2 : 0
}
end;

//比较两个文件名大小: AnsiCompareFileName
var
  s1,s2: AnsiString;
  i: Integer;
begin
  s1 := 'c:\temp\2.txt';
  s2 := 'c:\temp\1.TXT';

  i := AnsiCompareFileName(s1,s2);
  ShowMessage(IntToStr(i));   {1}

{有 3 种可能的返回值:
  s1 > s2 : 1
  s1 < s2 : -1
  s1 = s2 : 0
}
end;

//大小写转换: AnsiUpperCase、AnsiLowerCase
var
  ss,s: AnsiString;
begin
  ss := 'Hello';

  s := AnsiUpperCase(ss);
  ShowMessage(s); {HELLO}

  s := AnsiLowerCase(ss);
  ShowMessage(s); {hello}
end;

//文件名大小写转换: AnsiUpperCaseFileName、AnsiLowerCaseFileName
var
  ss,s: AnsiString;
begin
  ss := 'C:\Temp\1.txt';

  s := AnsiUpperCaseFileName(ss);
  ShowMessage(s); {C:\TEMP\1.TXT}

  s := AnsiLowerCaseFileName(ss);
  ShowMessage(s); {c:\temp\1.txt}
end;

//查找一个字符串在另一个字符串中最先出现的位置: AnsiPos
var
  ss,s: AnsiString;
  i: Integer;
begin
  ss := 'abcdefgcd';
  s := 'cd';

  i := AnsiPos(s,ss);
  ShowMessage(IntToStr(i)); {3}
end;

//添加定界符: AnsiQuotedStr
var
  ss,s: AnsiString;
begin
  ss := 'Hello';

  s := AnsiQuotedStr(ss, '"'); {参数2是定界符, Char 类型}
  ShowMessage(s);              {"Hello"}

  s := AnsiQuotedStr(ss, '#');
  ShowMessage(s);              {#Hello#}

  ss := 'Hello#Hello';         {如果中间包含要添加的定界符, 将被双写}
  s := AnsiQuotedStr(ss, '#');
  ShowMessage(s);              {#Hello##Hello#}
end;

//取消字符串两边的定界符: AnsiDequotedStr
var
  ss,s: AnsiString;
begin
  ss := '"Hello"';

  s := AnsiDequotedStr(ss, '"');
  ShowMessage(s); {Hello}
end;