Edit 的使用

//让 Edit 只接受数字



//方法1：

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);

begin

  if not (Key in ['0'..'9']) then

    Key := Chr(0);

end;



//方法2：

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);

begin

  if not (Byte(Key) in [48..57]) then  // 0的 Ascii 是 48

    Key := Chr(0);

end;



//方法3:

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);

begin

  if not CharInSet(Key, ['1'..'5']) then Key := #0;

end;




 
   




//Edit 文本的选择与光标位置

procedure TForm1.Button1Click(Sender: TObject);

begin

  Edit1.SetFocus;                           //给于焦点

  SendMessage(Edit1.Handle,EM_SETSEL,0,1);  //选择第一个字符

  SendMessage(Edit1.Handle,EM_SETSEL,0,-1); //全选

  SendMessage(Edit1.Handle,EM_SETSEL,1,1);  //光标移到第一个字符后面

  SendMessage(Edit1.Handle,EM_SETSEL,0,0);  //光标移到开始

  SendMessage(Edit1.Handle,EM_SETSEL,-1,0);  //光标移到开始

end;


 
   




//待续...