changing colours benina’s tutasm 2 changing colours of a dialog – ver 1 0 author benina benina’s tutasm 2 changing colours of a dialog author benina tut này tôi sẽ cùng bạn khám phá cách th

The SetBkColor function sets the current background color to the specified color value, or to the nearest physical color if the device cannot represent the specified color value.. COLOR[r]

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Benina’ s Tut ASM # 2 Changing Colours of a Dialog Author: Benina

Tut này sẽ cùng bạn khám phá cách thay đổi màu sắc giao diện của một chương trình dùng Dialog làm cửa sổ chính

Đây là Demo hòan hòan tất tut này:

Các bạn có thể download Source theo link: http://h1.ripway.com/benina/files/Keygen2.rar A.Lý thuyết:

Windows gởi các thông điệp rất đa dạng liên quan đến màu sắc đến thủ tục dialog của bạn, và bằng cách xử lý các thông điệp này bạn có thể thay đổi màu sắc nào mà bạn muốn hiển thị.Cho ví dụ, để thay đổi màu sắc của chính dialog box, bạn có thể xử lý thông điệp

WM_CTLCOLORDLG, để thay đổi màu sắc cho điều khiển static control , thì bạn xử lý thông điệp WM_CTLCOLORSTATIC và vân vân

Sau xin liệt kê một số thông điệp liên quan, bạn tra cứu Win32 API Reference để biết thêm chi tiết :

WM_CTLCOLORDLG, WM_CTLCOLOREDIT, WM_CTLCOLORLISTBOX,

WM_CTLCOLORMSGBOX, WM_CTLCOLORSCROLLBAR, WM_CTLCOLORSTATIC, WM_CTLCOLORBTN

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điệp được send thì cuối cùng bạn sẽ truy cập RAM rất nhiều với các brush die cũng nhiều vô số kể Vì vậy với cách cài đặt brush lưu nó biến, bạn sẽ dễ dàng điều khiển hơn, và chúng ta có thể xóa nó dialog bị hủy và chúng ta đã biết chúng ta ko dùng nó nữa

Hàm cài đặt brush là hàm sau và lưu nó vào biến:

(Các bạn tập tham khảo các hàm API bằng tiếng Anh cho quen, vì chắc chắn rất tiện lợi cho bạn sau này)

The CreateSolidBrush function creates a logical brush that has the specified solid color HBRUSH CreateSolidBrush(

COLORREF crColor // brush color value );

Parameters crColor

Specifies the color of the brush

Return Values

If the function succeeds, the return value identifies a logical brush. If the function fails, the return value is NULL

Remarks

A solid brush is a bitmap that Windows uses to paint the interiors of filled shapes

After an application creates a brush by calling CreateSolidBrush, it can select that brush into any device context by calling the SelectObject function.

Trong phần xử lý thông điệp WM_CTLCOLORDLG ta cho giá trị trả về là brush mà ta đã cài đặt

Trong phần xử lý các thông điệp liên quan WM_CTLCOLORSTATIC vân vân, ta co thể dùng SetBkMode, SetBkColor, SetTextColor để thay đổi màu sắc của control mà thông điệp chịu trách nhiệm.Các hàm này có ý nghĩa sau:

Chức của hàm SetBkMode là set một kiểu pha trộn bkground của DC ta chỉ định Kiểu pha trộn Bkground (background mix mode) được sử dụng với texts, hatched brushes và các lọai pen ko phải để vẽ line “đặc” (solid) Nó tác dụng đến các lọai line vẽ- sử dụng một pen bởi hàm cài đặt là CreatePen SetBkMode ko gây ảnh hưởng đến lines sử dụng hàm cài đặt

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Chức của hàm SetBkColor là set một bkground color hiện hành hay là màu tự nhiên gần nhất nếu device ko miêu tả giá trị màu được chỉ định Hàm này lắp các kẻ hở giữa các lines vẽ được định mẫu sử dụng hàm CreatePen để cài đặt

Hàm SetTextColor có chức set màu text

Các bạn có thể tham khảo các hàm này phần phụ lục của tut

-Và cuối cùng thóat chương trình chúng ta đừng quên free brush của chúng ta đã cài đặt khỏi memory bằng hàm DeleteObject

B.Thực hành:

Trong MASM ta thực hiện theo các bước sau:

Các bạn hãy thực hiện tiếp tục project mà ta đã làm ở tutorial “Benina’ Tut # 1” Hảy Open project Keygen1 Tut#1

1 Bước 1:

Trước tiên ta include thư viện để sử dụng các hàm API đồ họa file Keygen1.Inc:

include gdi32.inc includelib gdi32.lib

Kế đến khai báo các biến và hằng color file Keygen1.Inc: Trong section CONST khai báo hằng số màu color

; -; Colors

; -CR_BACKGROUND equ 00333300h

CR_TEXT equ 00CCCC99h Trong section DATA ?

Khai báo biến lưu Brush cài đặt hBgColor HBRUSH ?

2 Bước :

Trong file Keygen1.Asm , phần section CODE trước lời gọi hàm DialogBoxParam ta add lệnh sau để cài đặt Brush:

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Sau đó vòng lặp xử lý thông điệp ta add các lệnh: .ELSEIF uMsg == WM_CTLCOLORDLG mov eax, hBgColor

ret

.ELSEIF uMsg == WM_CTLCOLORSTATIC

INVOKE SetBkMode, wParam, TRANSPARENT INVOKE SetTextColor, wParam, CR_TEXT Invoke SetBkColor,wParam,CR_BACKGROUND mov eax, hBgColor

ret

.ELSEIF uMsg == WM_CTLCOLOREDIT INVOKE SetBkMode, wParam, TRANSPARENT INVOKE SetTextColor, wParam, CR_TEXT Invoke SetBkColor,wParam,CR_BACKGROUND mov eax, hBgColor

ret

Giải thích đôi chút:

-Ta biết thông điệp trả về giá trị eax, nên ta có các lệnh

mov eax, hBgColor ret

-Chú ý dòng lệnh Set Background Mode (hàm SetBkMode) tham số thứ là TRANSPARENT Nếu ko có dòng này thì Bkground sẽ được fill với brush mà bạn chỉ định , control vẽ text nó sẽ vẽ đè lên với default background color Vì vậy nếu ta setting với TRANSPARENT thì sẽ fix được vấn đề này

-Thay đổi màu của các control khác cũng tương tự Bạn tìm các thông điệp có dạng sau : WM_CTLCOLOR* message Win32 reference để tham khảo thêm Chú ý rằng, một edit control sẽ gởi thông điệp WM_CTLCOLORSTATIC nếu nó chỉ đọc (read only) và nếu khác thì nó sẽ send thông điệp WM_CTLCOLOREDIT

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3 Bước 3:

Cuối cùng chúng ta cần free Object Brush khỏi bộ nhớ Trước lệnh ExitProcess và sau lệnh DialogBoxParam file Keygen1.Asm ta add thêm lệnh:

INVOKE DeleteObject, hBgColor

Đây là hình ảnh sau thực hiện file Keygen1.Inc

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Sau thực hiện xong ta Hit nút “GO” xem sau nhé OK rồi chứ!

C.Phụ lục:

Tham khảo các hàm API: 1 SetBkMode :

The SetBkMode function sets the background mix mode of the specified device context The background mix mode is used with text, hatched brushes, and pen styles that are not solid lines

int SetBkMode(

HDC hdc, // handle of device context

int iBkMode // flag specifying background mode );

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hdc

Identifies the device context iBkMode

Specifies the background mode This parameter can be either of the following values: Value Description

OPAQUE Background is filled with the current background color before the text, hatched brush, or pen is drawn.

TRANSPARENT Background remains untouched.

Return Values

If the function succeeds, the return value specifies the previous background mode. If the function fails, the return value is zero

Remarks

The SetBkMode function affects the line styles for lines drawn using a pen created by the CreatePen function SetBkMode does not affect lines drawn using a pen created by the ExtCreatePen function

The iBkMode parameter can also be set to driver-specific values GDI passes such values to the device driver and otherwise ignores them.

2 SetBkColor

The SetBkColor function sets the current background color to the specified color value, or to the nearest physical color if the device cannot represent the specified color value

COLORREF SetBkColor(

HDC hdc, // handle of device context COLORREF crColor // background color value );

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Identifies the device context crColor

Specifies the new background color

Return Values

If the function succeeds, the return value specifies the previous background color as a COLORREF value

If the function fails, the return value is CLR_INVALID Remarks

This function fills the gaps between styled lines drawn using a pen created by the CreatePen function; it does not fill the gaps between styled lines drawn using a pen created by the

ExtCreatePen function

If the background mode is OPAQUE, the background color is used to fill gaps between styled lines, gaps between hatched lines in brushes, and character cells The background color is also used when converting bitmaps from color to monochrome and vice versa.

3 SetTextColor:

The SetTextColor function sets the text color for the specified device context to the specified color

COLORREF SetTextColor(

HDC hdc, // handle of device context COLORREF crColor // text color

);

Parameters hdc

Identifies the device context crColor

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Return Values

If the function succeeds, the return value is a color reference for the previous text color. If the function fails, the return value is CLR_INVALID To get extended error information, call GetLastError

Remarks

The text color is used to draw the face of each character written by the TextOut and ExtTextOut functions The text color is also used in converting bitmaps from color to monochrome and vice versa.

Hy vọng các bạn hài lòng Các bạn cần nghiên cứu thêm để Template của ta ngày càng đẹp Các bạn có thể download Source theo link:

http://h1.ripway.com/benina/files/Keygen2.rar

Benina 27/12/2005 Update 27/12/2005 Mail: info@123doc.org

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