C++ Builder XE8 上的 TEdit 输入验证

Question

我是 C++ Builder XE8 的新手。

我希望必须输入的数字的最小和最大长度是六个数字，我还需要确保只输入数字（0 除外），而不是字母字符、退格键、标点等

如果输入的不是数字，我还想生成一个错误框。

我已经尝试了一些代码组合，下面可以看到其中的三个，但是其中 none 个代码有效。

我们将不胜感激！

(1).

void __fastcall TForm1::Edit1KeyPress(TObject *Sender, System::WideChar &Key)
{
  Edit1->MaxLength = 6;

  if (!((int)Key == 1-9)) {
  ShowMessage("Please enter numerals only");
  Key = 0;
  }
}

(2).

void __fastcall TForm1::Edit1KeyPress(TObject *Sender, System::WideChar &Key)
{
  Edit1->MaxLength = 6;

  if (Key <1 && Key >9) {
  ShowMessage("Please enter numerals only");
  Key = 0;
  }
}

(3).

void __fastcall TForm1::Edit1KeyPress(TObject *Sender, System::WideChar &Key)
{
  Edit1->MaxLength = 6;

  if( Key == VK_BACK )
   return;

  if( (Key >= 1) && (Key <= 9) )
   {
  if(Edit1->Text.Pos(1-9) != 1 )
   ShowMessage("Please enter numerals only");
   Key = 1;
  return;
  }
}

Answer 1

查看 TMaskEdit：http://docs.embarcadero.com/products/rad_studio/delphiAndcpp2009/HelpUpdate2/EN/html/devwin32/idh_useop_textcontrols_xml.html

TMaskEdit is a special edit control that validates the text entered against a mask that encodes the valid forms the text can take. The mask can also format the text that is displayed to the user.

编辑：设置最小长度

void __fastcall TForm1::MaskEdit1Exit(TObject *Sender)
{
   if (MaskEdit1->Text.length() < 6)
   {
     //your error message, or throw an exception.
   }
}

Answer 2

TEdit 有一个 NumbersOnly 属性:

Allows only numbers to be typed into the text edit.

将其设置为 true 并让 OS 为您处理验证。但是，如果您想手动验证它，请使用：

void __fastcall TForm1::Edit1KeyPress(TObject *Sender, System::WideChar &Key)
{
    // set this at design-time, or at least
    // in the Form's constructor. It does not
    // belong here...
    //Edit1->MaxLength = 6;

    if( Key == VK_BACK )
        return;

    if( (Key < L'0') || (Key > L'9') )
    {
        ShowMessage("Please enter numerals only");
        Key = 0;
    }
}

C++ Builder XE8 上的 TEdit 输入验证

TEdit Input Validation on C++ Builder XE8

c++

c++builder

c++builder-xe8