DELPHI EDIT控件 使文字 垂直居中

S3_Leo

以下代码实现居中有如下弊端。密码格式隐藏失效。

1. 
   
2. USES StdCtrls;
   
3. type
   
4. TEdit = class(StdCtrls.TEdit)
   
5. 
   
6. protected
   
7. procedure CreateParams(var Params: TCreateParams); override;
   
8. 
   
9. procedure KeyPress(var Key: Char); override;
   
10. 
    
11. procedure WMSize(var msg: TWMSize);message WM_SIZE;
    
12. 
    
13. procedure SetParent(AParent: TWinControl);override;
    
14. 
    
15. procedure SetCenter;
    
16. 
    
17. end;
    
18. 
    
19. procedure TEdit.CreateParams(var Params: TCreateParams);
    
20. begin
    
21.   inherited;
    
22.   Params.Style := Params.Style or ES_MULTILINE;
    
23. end;
    
24. procedure TEdit.KeyPress(var Key: Char);
    
25. begin
    
26.   inherited;
    
27.   if Key = #13 then
    
28.      key := #0;
    
29. end;
    
30. procedure TEdit.SetCenter;
    
31. var
    
32. DC: HDC;
    
33. SaveFont: HFont;
    
34. Sin: Integer;
    
35. SysMetrics, Metrics: TTextMetric;
    
36. Rct: TRect;
    
37. begin
    
38. DC := GetDC(0);
    
39. GetTextMetrics(DC, SysMetrics);
    
40. SaveFont := SelectObject(DC, Font.Handle);
    
41. GetTextMetrics(DC, Metrics);
    
42. SelectObject(DC, SaveFont);
    
43. ReleaseDC(0, DC);
    
44. if Ctl3D then Sin := 8 else Sin := 6;
    
45. Rct := ClientRect;
    
46. Sin := Height - Metrics.tmHeight - Sin;
    
47. Rct.Top := Sin div 2;
    
48. SendMessage(Handle, EM_SETRECT, 0, Integer(@Rct));
    
49. end;
    
50. procedure TEdit.SetParent(AParent: TWinControl);
    
51. begin
    
52.   inherited;
    
53.   if Parent <> nil then
    
54.   begin
    
55.     SetCenter;
    
56.   end;
    
57. end;
    
58. procedure TEdit.WMSize(var msg: TWMSize);
    
59. begin
    
60.   inherited;
    
61.   SetCenter;
    
62. end;
    
63. 
    

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