上一篇讲了窗口及消息，了解了大体的程序框架。这一篇说的是控件的创建。
duilib支持XML配置文件，即根据XML创建窗口及控件，将界面与逻辑分开，便于修改及维护。上一篇的示例中可以看到在消息WM_CREATE中有控件创建的相关代码。
1 if( uMsg == WM_CREATE ) { 2 m_pm.Init(m_hWnd); 3 //根据XML创建控件 4 CDialogBuilder builder; 5 CControlUI* pRoot = builder.Create(_T("HelloWorld.xml"), (UINT)0, NULL, &m_pm); 6 ASSERT(pRoot && "Failed to parse XML"); 7 m_pm.AttachDialog(pRoot); 8 m_pm.AddNotifier(this); 9 return 0; 10 }
控件创建主要牵扯到类CDialogBuilder：
- 创建控件树，返回根控件：CDialogBuilder::Create
- 将控件树关联到CPaintManagerUI对象（由名字可猜出其功能与绘制控件有关）：CPaintManagerUI::AttachDialog
- 添加消息通知：CPaintManagerUI::AddNotifier
创建控件树：
- 读取XML配置文件
1 CControlUI* CDialogBuilder::Create(STRINGorID xml, LPCTSTR type, IDialogBuilderCallback* pCallback, 2 CPaintManagerUI* pManager, CControlUI* pParent) 3 { 4 if( HIWORD(xml.m_lpstr) != NULL ) { 5 if( *(xml.m_lpstr) == _T('<') ) { 6 if( !m_xml.Load(xml.m_lpstr) ) return NULL; 7 } 8 else { 9 if( !m_xml.LoadFromFile(xml.m_lpstr) ) return NULL; 10 } 11 } 12 else { 13 HRSRC hResource = ::FindResource(CPaintManagerUI::GetResourceDll(), xml.m_lpstr, type); 14 if( hResource == NULL ) return NULL; 15 HGLOBAL hGlobal = ::LoadResource(CPaintManagerUI::GetResourceDll(), hResource); 16 if( hGlobal == NULL ) { 17 FreeResource(hResource); 18 return NULL; 19 } 20 21 m_pCallback = pCallback; 22 if( !m_xml.LoadFromMem((BYTE*)::LockResource(hGlobal), ::SizeofResource(CPaintManagerUI::GetResourceDll(), hResource) )) return NULL; 23 ::FreeResource(hResource); 24 m_pstrtype = type; 25 } 26 27 return Create(pCallback, pManager); 28 }
- 解析Image（图片）、Font（字体）、Default（默认属性）、Windows（窗口相关）项（代码太长，省略了细节）
1 CControlUI* CDialogBuilder::Create(IDialogBuilderCallback* pCallback, CPaintManagerUI* pManager, CControlUI* pParent) 2 { 3 m_pCallback = pCallback;//回调函数，用于创建自定义控件 4 CMarkupNode root = m_xml.GetRoot(); 5 if( !root.IsValid() ) return NULL; 6 7 if( pManager ) { 8 LPCTSTR pstrClass = NULL; 9 int nAttributes = 0; 10 LPCTSTR pstrName = NULL; 11 LPCTSTR pstrValue = NULL; 12 LPTSTR pstr = NULL; 13 for( CMarkupNode node = root.GetChild() ; node.IsValid(); node = node.GetSibling() ) { 14 pstrClass = node.GetName(); 15 if( _tcscmp(pstrClass, _T("Image")) == 0 ) {//Image 16 } 17 else if( _tcscmp(pstrClass, _T("Font")) == 0 ) {//Font 18 } 19 else if( _tcscmp(pstrClass, _T("Default")) == 0 ) {//Default 20 } 21 } 22 23 pstrClass = root.GetName(); 24 if( _tcscmp(pstrClass, _T("Window")) == 0 ) {//Window 25 } 26 } 27 return _Parse(&root, NULL, pManager); 28 }
- 创建控件：CDialogBuilder::_Parse
- 可以通过include嵌套XML文件
1 。。。。。。 2 if( _tcscmp(pstrClass, _T("Include")) == 0 ) {//Include 3 if( !node.HasAttributes() ) continue; 4 int count = 1; 5 LPTSTR pstr = NULL; 6 TCHAR szValue[500] = { 0 }; 7 SIZE_T cchLen = lengthof(szValue) - 1; 8 if ( node.GetAttributeValue(_T("count"), szValue, cchLen) ) 9 count = _tcstol(szValue, &pstr, 10); 10 cchLen = lengthof(szValue) - 1; 11 if ( !node.GetAttributeValue(_T("source"), szValue, cchLen) ) continue; 12 for ( int i = 0; i < count; i++ ) { 13 CDialogBuilder builder; 14 if( m_pstrtype != NULL ) { // 使用资源dll，从资源中读取 15 WORD id = (WORD)_tcstol(szValue, &pstr, 10); 16 pControl = builder.Create((UINT)id, m_pstrtype, m_pCallback, pManager, pParent); 17 } 18 else { 19 pControl = builder.Create((LPCTSTR)szValue, (UINT)0, m_pCallback, pManager, pParent); 20 } 21 } 22 continue; 23 } 24 。。。。。。
- 创建控件（自定义控件调用回调函数实现）
。。。。。。 else {//新建控件 SIZE_T cchLen = _tcslen(pstrClass); switch( cchLen ) { case 4: if( _tcscmp(pstrClass, _T("Edit")) == 0 ) pControl = new CEditUI; else if( _tcscmp(pstrClass, _T("List")) == 0 ) pControl = new CListUI; else if( _tcscmp(pstrClass, _T("Text")) == 0 ) pControl = new CTextUI; break; case 5: if( _tcscmp(pstrClass, _T("Combo")) == 0 ) pControl = new CComboUI; else if( _tcscmp(pstrClass, _T("Label")) == 0 ) pControl = new CLabelUI; break; case 6: if( _tcscmp(pstrClass, _T("Button")) == 0 ) pControl = new CButtonUI; else if( _tcscmp(pstrClass, _T("Option")) == 0 ) pControl = new COptionUI; else if( _tcscmp(pstrClass, _T("Slider")) == 0 ) pControl = new CSliderUI; break; case 7: if( _tcscmp(pstrClass, _T("Control")) == 0 ) pControl = new CControlUI; else if( _tcscmp(pstrClass, _T("ActiveX")) == 0 ) pControl = new CActiveXUI; break; case 8: if( _tcscmp(pstrClass, _T("Progress")) == 0 ) pControl = new CProgressUI; else if( _tcscmp(pstrClass, _T("RichEdit")) == 0 ) pControl = new CRichEditUI; break; case 9: if( _tcscmp(pstrClass, _T("Container")) == 0 ) pControl = new CContainerUI; else if( _tcscmp(pstrClass, _T("TabLayout")) == 0 ) pControl = new CTabLayoutUI; else if( _tcscmp(pstrClass, _T("ScrollBar")) == 0 ) pControl = new CScrollBarUI; break; case 10: if( _tcscmp(pstrClass, _T("ListHeader")) == 0 ) pControl = new CListHeaderUI; else if( _tcscmp(pstrClass, _T("TileLayout")) == 0 ) pControl = new CTileLayoutUI; break; case 12: if( _tcscmp(pstrClass, _T("DialogLayout")) == 0 ) pControl = new CDialogLayoutUI; break; case 14: if( _tcscmp(pstrClass, _T("VerticalLayout")) == 0 ) pControl = new CVerticalLayoutUI; else if( _tcscmp(pstrClass, _T("ListHeaderItem")) == 0 ) pControl = new CListHeaderItemUI; break; case 15: if( _tcscmp(pstrClass, _T("ListTextElement")) == 0 ) pControl = new CListTextElementUI; break; case 16: if( _tcscmp(pstrClass, _T("HorizontalLayout")) == 0 ) pControl = new CHorizontalLayoutUI; else if( _tcscmp(pstrClass, _T("ListLabelElement")) == 0 ) pControl = new CListLabelElementUI; break; case 20: if( _tcscmp(pstrClass, _T("ListContainerElement")) == 0 ) pControl = new CListContainerElementUI; break; } // User-supplied control factory if( pControl == NULL && m_pCallback != NULL ) { pControl = m_pCallback->CreateControl(pstrClass); } } 。。。。。。
- 添加子控件（解析子控件：递归调用_Parse、关联到父控件：CContainerUI::Add）
1 。。。。。。 2 // Add children 3 if( node.HasChildren() ) { 4 _Parse(&node, pControl, pManager); 5 } 6 // Attach to parent 7 // 因为某些属性和父窗口相关，比如selected，必须先Add到父窗口 8 if( pParent != NULL ) { 9 if( pContainer == NULL ) pContainer = static_cast<IContainerUI*>(pParent->GetInterface(_T("IContainer"))); 10 ASSERT(pContainer); 11 if( pContainer == NULL ) return NULL; 12 if( !pContainer->Add(pControl) ) { 13 delete pControl; 14 continue; 15 } 16 } 17 。。。。。。
- 返回根控件
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1 。。。。。。 2 // Return first item 3 if( pReturn == NULL ) pReturn = pControl; 4 。。。。。。
- 可以通过include嵌套XML文件
控件创建基本就这些，下一篇写控件消息。