100分----RichEdit控件中对输入的汉字作判断，正确的字显示蓝色，错误的显红色

Question

在做打字程序时，在RichEdit控件中对输入的汉字作判断，正确的字显示蓝色，错误的显红色，怎么写程序？

Answer 1

procedure TForm1.RichEdit1Change(Sender: TObject);
var Startpos,Toend,x,y:integer;
    curstring:string;
begin
     curstring:=RichEdit1.Lines[RichEdit1.Lines.Count-1];;
     StartPos := 0;
     ToEnd := length(Richedit2.text)-1;
     X := Richedit2.FindText(curstring,StartPos,toEnd,[stMatchCase]);
     if x<>-1 then
     begin
        Richedit2.SetFocus;
        Richedit2.selstart := X;
        RichEdit2.SelLength := Length(curstring);
        RichEdit2.SelAttributes.Color:=clRed;
     end;
end;

Answer 2

//判断汉字的方法
procedure TForm1.Button1Click(Sender: TObject);
var
  s:string;
begin
  s:=Edit1.Text;
  if ord(s[9])>128 then
    ShowMessage('该位置字符是汉字');
end;

Answer 3

我代码是这样写的，不能正确显示颜色，帮我看看有什么问题？procedure TFrmTextInput.RichEditInputChange(Sender: TObject);
var
        i,j:integer;//i,j 分别记录样本字符串和录入字符串的字符的位置
        Cusor:integer;//记录光标的位置
        index:integer;
        Samplelength,InputLength:integer;//记录两字符串的总长度begin
       strSample:=RichEditSample.Text;
        strInput:=RichEditInput.Text;
        Cusor:=RichEditInput.SelStart;
        index:=cusor div 2;  //使光标位置和字符串数组的位置一致
  //     SampleLength:=length(strSample);
  //     InputLength:=length(strInput);
       // 将输入的字体颜色预置为蓝颜色
       RichEditInput.DefAttributes.Color:=clBlue;
       //对输入的字是否正确作判断，若不正确，则改变它的颜色
    if cusor>=1 then
       if strInput[index]<>strSample[index] then
           begin
                  //　将刚才输入的字置于红颜色                  RichEditInput.selStart:=cusor-2 ;
                  RichEditInput.selLength:=2;
                  RichEditInput.SelAttributes.Color:=clRed;
                  //  恢复光标的位置
                 RichEditInput.selStart:=cusor;
                  //  重置于蓝颜色
                RichEditInput.selAttributes.color:=clBlue;
           end;