delphi – 以编程方式显示Balloon提示仅用于无效的文本编辑输入

您的代码适用于我(在XE4和XE6中)第一次(和第二次)进行此更改：

R := Edit1.BoundsRect;
  R.TopLeft := ClientToScreen(R.TopLeft);
  R.BottomRight := ClientToScreen(R.BottomRight);
  BalloonHint1.Description := 'bad input';   <---- this was missing
  BalloonHint1.ShowHint(R);   //!!! Issue: No hint the first time around

所以,如果第二次它确实适合你,我认为这是因为你没有展示的代码,同样你没有展示的东西可能就是为什么它不起作用的第一次.所以你可以“发现差异”,我的项目代码如下.我找不到你的StrIsReal函数,所以我自己动手了.

顺便说一句,我在我的表单中添加了第二个TEdit,因此还有其他东西可以失去焦点,并注释掉了你的两个Edit1.ShowHint作业,因为它们没有任何区别,但无论如何都不需要.

TForm1 = Class(TForm)
  [...]
    FBalloonHint : TBalloonHint;
    procedure WMActivateApp(var AMessage: TMessage); message WM_ActivateApp;
    procedure WMWindowPosChanged(var AMessage: TMessage);  message WM_WindowPosChanged;
  [...]
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  FBalloonHint := TBalloonHint.Create(Self);
  FBalloonHint.HideAfter := 5000;
  FBalloonHint.Delay := 0;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  R: TRect;
begin
  FBalloonHint.Description := 'You pressed ' + Button1.Caption;
  R := Button1.BoundsRect;
  R.TopLeft := ClientToScreen(R.TopLeft);
  R.BottomRight := ClientToScreen(R.BottomRight);
  FBalloonHint.ShowHint(R);
end;

procedure TForm1.Edit1Exit(Sender: TObject);
var
  R: TRect;
  Bad : Boolean;
  F : Double;

  function StrIsReal(S : String) : Boolean;
  begin
    Result := True;
  end;

begin
  //Check if edit has only numbers
  if StrIsReal(Edit1.Text) then
  begin
    if(StrToFloat(Edit1.Text) >= 0.5) then
    begin
      //Value is ok
      SpeedButton1.Visible := false;
      //Edit1.ShowHint := false;
      FBalloonHint.HideHint;
      Edit1.Text := FloatToStrF(StrToFloat(Edit1.Text),but not at least 0.5
      Bad := true;
    end;
  end
  else
  begin
    Bad := true;
  end;

  if Bad then
  begin
    //Invalid number
    //Edit1.ShowHint := true;

    Edit1.Text := '0.00';
    SpeedButton1.Visible := true;

    R := Edit1.BoundsRect;
    R.TopLeft := ClientToScreen(R.TopLeft);
    R.BottomRight := ClientToScreen(R.BottomRight);
    FBalloonHint.Description := 'bad input';
    FBalloonHint.ShowHint(R);   //!!! Issue: No hint the first time around
  end;
end;

procedure TForm1.SpeedButton1Click(Sender: TObject);
begin
  Edit1Exit(Sender);
end;

procedure TForm1.WMActivateApp(var AMessage: TMessage);
begin
  if Assigned(FBalloonHint) then FBalloonHint.HideHint;
  inherited;
end;

procedure TForm1.WMWindowPosChanged(var AMessage: TMessage);
begin
  if Assigned(FBalloonHint) then FBalloonHint.HideHint;
  inherited;
end;