InputQuery
函数功能InputQuery里输入的字显示为密码“*”
函数原型实例function InputQuery(const ACaption, APrompt: string;
var Value: string): Boolean;
function GetAveCharSize(Canvas: TCanvas): TPoint;
var
I: Integer;
Buffer: array[0..51] of Char;
begin
for I := 0 to 25 do Buffer[I] := Chr(I + Ord('A'));
for I := 0 to 25 do Buffer[I + 26] := Chr(I + Ord('a'));
GetTextExtentPoint(Canvas.Handle, Buffer, 52, TSize(Result));
Result.X := Result.X div 52;
end;
var
Form: TForm;
Prompt: TLabel;
Edit: TEdit;
DialogUnits: TPoint;
ButtonTop, ButtonWidth, ButtonHeight: Integer;
begin
Result := False;
Form := TForm.Create(Application);
with Form do
try
Canvas.Font := Font;
Font.Charset := GB2312_CHARSET;
Font.Size := 9;
DialogUnits := GetAveCharSize(Canvas);
BorderStyle := bsDialog;
Caption := ACaption;
ClientWidth := MulDiv(180, DialogUnits.X, 4);
Position := poScreenCenter;
Prompt := TLabel.Create(Form);
with Prompt do
begin
Parent := Form;
Caption := APrompt;
Left := MulDiv(8, DialogUnits.X, 4);
Top := MulDiv(8, DialogUnits.Y, 8);
Constraints.MaxWidth := MulDiv(164, DialogUnits.X, 4);
WordWrap := True;
end;
Edit := TEdit.Create(Form);
with Edit do
begin
PasswordChar := '*';
Parent := Form;
Left := Prompt.Left;
Top := Prompt.Top + Prompt.Height + 5;
Width := MulDiv(164, DialogUnits.X, 4);
MaxLength := 255;
Text := Value;
SelectAll;
end;
ButtonTop := Edit.Top + Edit.Height + 15;
ButtonWidth := MulDiv(50, DialogUnits.X, 4);
ButtonHeight := MulDiv(14, DialogUnits.Y, 8);
with TButton.Create(Form) do
begin
Parent := Form;
Caption := '取消';
ModalResult := mrCancel;
Cancel := True;
SetBounds(MulDiv(92, DialogUnits.X, 4), Edit.Top + Edit.Height + 15,
ButtonWidth, ButtonHeight);
Form.ClientHeight := Top + Height + 13;
Left := (Edit.Left + Edit.Width) - Width;
end;
with TButton.Create(Form) do
begin
Parent := Form;
Caption := '确定';
ModalResult := mrOk;
Default := True;
SetBounds(MulDiv(38, DialogUnits.X, 4), ButtonTop, ButtonWidth,
ButtonHeight);
Left := (Edit.Left + Edit.Width) - (Width * 2) - 4;
end;
if ShowModal = mrOk then
begin
Value := Edit.Text;
Result := True;
end;
finally
Form.Free;
end;
end;