Question

基本上我有这个问题：CapsLock password message in TEdit visually fails with VCL Styles。

我想做的不是解决问题，如答案或评论中所示。

我想完全禁用那个丑陋的提示窗口。而是显示一个图像，让用户知道上限被锁定。

像这样

Answer 1

我找到了问题的解决方案，它涉及到我宁愿不使用的黑客攻击。

就是这样。

覆盖WndProc。

码

type
  TEdit = class (Vcl.StdCtrls.TEdit)
  protected
    procedure WndProc(var Message: TMessage); override;
  end;

拦截EM_SHOWBALLOONTIP消息，您已完成

码

procedure TEdit.WndProc(var Message: TMessage);
begin
 if Message.Msg = EM_SHOWBALLOONTIP then
   showmessage('Do your thing.')
 else
  inherited;
end;

有关详细信息，请查看MSDN文档：

How do I suppress the CapsLock warning on password edit controls?

这是TEdit的后代，如果某个FOnPasswordCaps事件分配了PasswordChar <> #0

unit NCREditUnit;

interface

uses
  Vcl.StdCtrls,
  vcl.Controls,
  Winapi.Messages,
  System.Classes;

type
  TNCREdit = class(TEdit)
  private
    FOnPasswordCapsLocked: TNotifyEvent;
    FIsCapsLocked: boolean;
    FOnPasswordCapsFreed: TNotifyEvent;
    FBlockCapsBalloonTip: boolean;
    FValuePasswordChrOnCaps: boolean;
    procedure SetOnPasswordCapsEvents;
    procedure SetOnPasswordCapsFreed(const aValue: TNotifyEvent);
    procedure SetOnPasswordCapsLocked(const aValue: TNotifyEvent);
  protected
    procedure WndProc(var Message: TMessage); override;
    procedure KeyUp(var Key: Word; Shift: TShiftState); override;
    procedure DoEnter; override;
    procedure DoExit; override;
  published
    property BlockCapsBalloonTip: boolean read FBlockCapsBalloonTip write FBlockCapsBalloonTip default False;
    property ValuePasswordChrOnCaps: boolean read FValuePasswordChrOnCaps write FValuePasswordChrOnCaps default True;

//... The usual property declaration of TEdit

    property OnPasswordCapsLocked: TNotifyEvent read FOnPasswordCapsLocked write SetOnPasswordCapsLocked;
    property OnPasswordCapsFreed: TNotifyEvent read FOnPasswordCapsFreed write SetOnPasswordCapsFreed;
  end;


implementation

uses
  Winapi.CommCtrl,
  Winapi.Windows;

{ TNCREdit }

procedure TNCREdit.DoEnter;
begin
  inherited;
  if FBlockCapsBalloonTip then
    begin
      FIsCapsLocked := Odd(GetKeyState(VK_CAPITAL));
      SetOnPasswordCapsEvents;
    end;
end;

procedure TNCREdit.DoExit;
begin
  if FBlockCapsBalloonTip and (FIsCapsLocked) then
    begin
      FIsCapsLocked := False;
      SetOnPasswordCapsEvents;
    end;
  inherited;
end;

procedure TNCREdit.KeyUp(var Key: Word; Shift: TShiftState);
begin
  if Key = VK_CAPITAL then
    FIsCapsLocked := not FIsCapsLocked;
  SetOnPasswordCapsEvents;
  inherited;
end;

procedure TNCREdit.SetOnPasswordCapsEvents;
begin
  if FIsCapsLocked then
    begin
      if Assigned(FOnPasswordCapsLocked) and
         ((self.PasswordChar <> #0) or ( not FValuePasswordChrOnCaps)) then
      begin
      FOnPasswordCapsLocked(Self);
      end;
    end
  else
    begin
      if Assigned(FOnPasswordCapsLocked) and
         ((self.PasswordChar <> #0) or ( not FValuePasswordChrOnCaps)) then
      begin
      FOnPasswordCapsFreed(Self);
      end;
    end;
end;

procedure TNCREdit.SetOnPasswordCapsFreed(const aValue: TNotifyEvent);
begin
  FOnPasswordCapsFreed := aValue;
  FBlockCapsBalloonTip := True;
end;

procedure TNCREdit.SetOnPasswordCapsLocked(const aValue: TNotifyEvent);
begin
  FOnPasswordCapsLocked := aValue;
  FBlockCapsBalloonTip := True;
end;

procedure TNCREdit.WndProc(var Message: TMessage);
begin
  if (Message.Msg = EM_SHOWBALLOONTIP) and FBlockCapsBalloonTip then Exit; 
  inherited;
end;

end.

Kobik先生制作了一段非常优雅的代码，我认为不应该信任PasteBin，所以我决定在这里添加它。

根据我的理解，它允许您在TPasswordCapsLockState获得焦点时失效的一个事件处理程序中处理TPasswordEdit，失去焦点，在焦点处按下CapsLock键并在{{1时触发可选触发改变了。

使用这种方法，我可以使用PasswordChar事件来显示/隐藏我的问题中的图像，而不是强迫组件的使用者为每个状态使用两个事件处理程序（顺便说一句，非常聪明，错误少）易发生）。

只要OnPasswordCapsLock为LNeedHandle := FBlockCapsBalloonTip and IsPassword;我还有True的另一个附加功能，即TPasswordEdit中OnEnter和OnExit的处理同样，

那么我怎能说Kobik先生 Je vous tire mon chapeau。

OnPasswordCapsLock

如何覆盖调用以在TEdit中显示CapsLock提示窗口？

1 个答案: