DevExpress 组件后代中未触发 OnKeyPress

Question

下面的代码定义了一个

TcxDBBlobEdit

后代及其自己的

OnKeyPress

。
我的问题是这个

OnKeyPress

（“此处断点”）永远不会被触发。
我忽略了什么？

type
  TPasswordTcxDBBlobEdit = class(TcxDBBlobEdit)    // DevExpress component
  private
    procedure SetPasswordMode(const Value: Boolean);
  protected
     FPasswordMode : Boolean;
     FPasswordChar : Char;
     FPrivateKeyFld: String;
     procedure WMPaste(var Message: TWMPaste); message WM_PASTE;
  public
     property PasswordMode: Boolean read FPasswordMode write SetPasswordMode;
     property PasswordChar: Char write FPasswordChar;
     property PrivateKeyFld: String write FPrivateKeyFld;
     constructor Create(AOwner: TComponent); override;
     procedure KeyPress(var Key: Char); override; Key: Char); override;
  end;

{ TPasswordTcxDBBlobEdit }

constructor TPasswordTcxDBBlobEdit.Create(AOwner: TComponent);
begin
   inherited;
   FPasswordMode := false;
   FPasswordChar := '*';
end;

procedure TPasswordTcxDBBlobEdit.KeyPress(var Key: Char);
var
   lCtrl,
   lShift,
   lPaste: Boolean;
begin
   if not FPasswordMode then Exit;  // <-- Breakpoint here
   lCtrl  := (GetKeyState(VK_CONTROL) < 0); // High bit set
   lShift := (GetKeyState(VK_SHIFT) < 0);
   lPaste := lCtrl and ((Key = 'V') or (Key = 'v') or (Key = #$16))   // #$16 https://stackoverflow.com/questions/78928063/weird-16-value-for-v-character-in-onkeypress
             or
             lShift and (GetKeyState(VK_INSERT) < 0);
   if not lPaste then
      Key := #0;

  inherited;
end;

在FormCreate中创建新组件：

procedure TDialoogEditProvider.FormCreate(Sender: TObject);
begin
   FEditFTPPrivateKey := TPasswordTcxDBBlobEdit.Create(nil);   // Before inherited because this assigns FEditFTPPrivateKey.DataBinding.DataSource/DataField
   
   FEditFTPPrivateKey.PasswordMode := true;                   
   FEditFTPPrivateKey.Parent       := PanelFTP;
   FEditFTPPrivateKey.Properties.BlobEditKind                   := bekMemo;
   FEditFTPPrivateKey.Properties.BlobPaintStyle                 := bpsText;
   FEditFTPPrivateKey.Properties.ImmediateDropDownWhenActivated := False;
   FEditFTPPrivateKey.TabOrder     := ComboFTPType.TabOrder + 1;
   FEditFTPPrivateKey.Width        := ComboFTPType.Width;
   FEditFTPPrivateKey.Height       := ComboFTPType.Height;
   FEditFTPPrivateKey.Left         := ComboFTPType.Left;
   FEditFTPPrivateKey.Top          := ComboFTPType.Top + ComboFTPType.Height + 4;
   FEditFTPPrivateKey.ScrollBars   := ssVertical;
   FEditFTPPrivateKey.Hint         := sReadOnlyButPaste;
   
   inherited;
end;

• 这是一个 Delphi 12 64 位应用程序

• Assigned(FEditFTPPrivateKey.OnKeyPress)

  在

  FormCreate

的末尾为真

Answer 1

BrakNicku 的评论成功了：

继承是

TcxDBBlobEdit

- >

TcxDBBlobEdit

->

TcxCustomBlobEdit

它是类型为

(Tcx)Memo

的弹出编辑器，并且 that 需要

OnKeypress handler

。

工作代码现在是：

type
  TPasswordTcxDBBlobEdit = class(TcxDBBlobEdit)
  private
     procedure SetPasswordMode(const Value: Boolean);
     procedure MemoKeyPress(Sender: TObject; var Key: Char);
  protected
     FPasswordMode : Boolean;
     FPasswordChar : Char;
     FPrivateKeyFld: String;
     procedure WMPaste(var Message: TWMPaste); message WM_PASTE;
  public
     property PasswordMode: Boolean read FPasswordMode write SetPasswordMode;
     property PasswordChar: Char write FPasswordChar;
     property PrivateKeyFld: String write FPrivateKeyFld;
     constructor Create(AOwner: TComponent); override;
     procedure PropertiesPopup(Sender: TObject);
  end;

procedure TPasswordTcxDBBlobEdit.PropertiesPopup(Sender: TObject);
begin
   ((Sender as TcxDBBlobEdit).Properties.PopupControl as TcxPopupMemo).OnKeyPress := MemoKeyPress;
   inherited;
end;

procedure TPasswordTcxDBBlobEdit.MemoKeyPress(Sender: TObject; var Key: Char);
var
   lCtrl,
   lShift,
   lPaste: Boolean;
begin
   if not FPasswordMode then Exit;  // Alles toegestaan
   lCtrl  := (GetKeyState(VK_CONTROL) < 0); // High bit set
   lShift := (GetKeyState(VK_SHIFT) < 0);
   lPaste := lCtrl and ((Key = 'V') or (Key = 'v') or (Key = #$16))   // #$16 https://stackoverflow.com/questions/78928063/weird-16-value-for-v-character-in-onkeypress
             or
             lShift and (GetKeyState(VK_INSERT) < 0);
   if not lPaste then
      Key := #0;

  inherited;
end;

（更新了标题并在问题中添加了 DevExpress 标签，因为这是相关的）