【原创】ComboBox的用法及注意事项

简介: 【原创】ComboBox的用法及注意事项

今天在写一个程序时,用到了CBS_DROPDOWNLIST 风格的ComboBox控件,但这个在资源文件中写的ComboBox控件,尽管顺利的加入了项目,但下拉列表显示不出来。

经过分析发现,是这个ComboBox控件的高度设置得太小引起。

可参考下面的演示代码:

;<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
; FileName: combobox.asm
;  Function: Demo the usage of comboxbox
;     Author: Purple Endurer
;
;  LOG
;----------------------------------------------------------------------------------
; 2005-08-08 Created!
;<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
.386
.model flat,stdcall
option casemap:none
include /masm32/include/windows.inc
include /masm32/include/user32.inc
include /masm32/include/kernel32.inc
includelib /masm32/lib/user32.lib
includelib /masm32/lib/kernel32.libWinMain proto :DWORD,:DWORD,:DWORD,:DWORD
.data
ClassName db "SimpleWinClass",0
AppName  db "Our First Window",0
g_szComboBoxCls db "ComboBox", 0.data?
hInstance HINSTANCE ?
g_hcbDemo1   HANDLE  ?
g_hcbDemo2   HANDLE  ?.code
start:
 invoke GetModuleHandle, NULL
 mov    hInstance,eax
 invoke WinMain, hInstance,NULL,NULL, SW_SHOWDEFAULT
 invoke ExitProcess,eaxWinMain proc hInst:HINSTANCE,hPrevInst:HINSTANCE,CmdLine:LPSTR,CmdShow:DWORD
 LOCAL wc:WNDCLASSEX
 LOCAL msg:MSG
 LOCAL hwnd:HWND
 mov   wc.cbSize,SIZEOF WNDCLASSEX
 mov   wc.style, CS_HREDRAW or CS_VREDRAW
 mov   wc.lpfnWndProc, OFFSET WndProc
 mov   wc.cbClsExtra,NULL
 mov   wc.cbWndExtra,NULL
 push  hInstance
 pop   wc.hInstance
 mov   wc.hbrBackground,COLOR_WINDOW+1
 mov   wc.lpszMenuName,NULL
 mov   wc.lpszClassName,OFFSET ClassName
 invoke LoadIcon,NULL,IDI_APPLICATION
 mov   wc.hIcon,eax
 mov   wc.hIconSm,eax
 invoke LoadCursor,NULL,IDC_ARROW
 mov   wc.hCursor,eax
 invoke RegisterClassEx, addr wc
 INVOKE CreateWindowEx,NULL,ADDR ClassName,ADDR AppName,/
           WS_OVERLAPPEDWINDOW,CW_USEDEFAULT,/
           CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,NULL,NULL,/
           hInst,NULL
 mov   hwnd,eax
 invoke ShowWindow, hwnd,SW_SHOWNORMAL
 invoke UpdateWindow, hwnd
 .WHILE TRUE
  invoke GetMessage, ADDR msg,NULL,0,0
  .BREAK .IF (!eax)
  invoke TranslateMessage, ADDR msg
  invoke DispatchMessage, ADDR msg
 .ENDW
 mov     eax,msg.wParam
 ret
WinMain endpWndProc proc hWnd:HWND, uMsg:UINT, wParam:WPARAM, lParam:LPARAM
 .IF uMsg==WM_DESTROY
  invoke PostQuitMessage,NULL
 .ELSEIF uMsg==WM_CREATE
                    ;创建正常的COMBOBOX
                    INVOKE CreateWindowEx, WS_EX_PALETTEWINDOW or WS_EX_CLIENTEDGE,/
                        ADDR g_szComboBoxCls, ADDR AppName,/
                        WS_CHILD or WS_VISIBLE or WS_VSCROLL or WS_TABSTOP or/
                         CBS_DROPDOWNLIST,/
                        30, 0, 180, 150, hWnd,/
                        400, hInstance, NULL                    mov g_hcbDemo1, eax
                    INVOKE SendMessage, g_hcbDemo1, CB_ADDSTRING, 0, ADDR g_szComboBoxCls
                    INVOKE SendMessage, g_hcbDemo1, CB_ADDSTRING, 0, ADDR AppName                    INVOKE SendMessage, g_hcbDemo1, CB_SETCURSEL, 0, 0
                    ;下面这个combox会因高度设置太低(为10)而无法显示下拉列表
                    INVOKE CreateWindowEx, WS_EX_PALETTEWINDOW or WS_EX_CLIENTEDGE,/
                        ADDR g_szComboBoxCls, ADDR AppName,/
                        WS_CHILD or WS_VISIBLE or WS_VSCROLL or WS_TABSTOP or/
                         CBS_DROPDOWNLIST,/
                        30, 40, 180, 10, hWnd,/
                        401, hInstance, NULL                    mov g_hcbDemo2, eax
                    INVOKE SendMessage, g_hcbDemo2, CB_ADDSTRING, 0, ADDR g_szComboBoxCls
                    INVOKE SendMessage, g_hcbDemo2, CB_ADDSTRING, 0, ADDR AppName                    INVOKE SendMessage, g_hcbDemo2, CB_SETCURSEL, 0, 0
 .ELSE
  invoke DefWindowProc,hWnd,uMsg,wParam,lParam  
  ret
 .ENDIF
 xor eax,eax
 ret
WndProc endp
end start
相关文章
|
10月前
《QT从基础到进阶·一》QString字符串常用方式
《QT从基础到进阶·一》QString字符串常用方式
99 0
|
关系型数据库 MySQL 数据库
Click高级用法|学习笔记
快速学习Click高级用法
171 0
Click高级用法|学习笔记
|
安全 iOS开发
iOS开发 - 字面语法之数组注意事项
iOS开发 - 字面语法之数组注意事项
79 0
|
C#
WPF Path.Data 后台代码赋值
Path path = new Path(); string sData = "M 250,40 L200,20 L200,60 Z"; var converter = TypeDescriptor.
1901 0
|
JavaScript .NET 开发框架