win32强化练习4.7_快速建立TreeView

这一节的练习就是快速建立一个TreeVew，我们分成2步来完成，第1步是用WIN32 SDK，第2步是自己封装类来简化操作。

首先是WIN32 SDK建立一个TreeView：

1. 包含头文件：#include

2. 声明HWND hTreeView后，使用CreateWindow建立一个TreeView，为了方便观察，加上WS_BORDER出现边框

3. 使用和操作TreeView的结构体：TVINSERTSTRUCT tvs; 利用tvs.item.pszText来改变标题，tvs.hParent来指定是根目录还是某个目录的子节点

HWND hTreeView;

hTreeView = CreateWindow("SysTreeView32",NULL,WS_CHILD|WS_BORDER|
			WS_VISIBLE|TVS_HASLINES|TVS_HASBUTTONS|TVS_LINESATROOT,
			10,20,200,400,hWnd,NULL,hInst,NULL);

TVINSERTSTRUCT tvs;
			tvs.item.mask = TVIF_TEXT;
			tvs.hInsertAfter = TVI_LAST;

tvs.item.pszText = "Node1";
			tvs.hParent = NULL;	//根节点1 
			HTREEITEM hNode1 = (HTREEITEM)SendMessage(hTreeView,
				TVM_INSERTITEM,0,(LPARAM)&tvs);
			tvs.item.pszText = "Item1"; 
			tvs.hParent = hNode1;	//子节点1 
			(HTREEITEM)SendMessage(hTreeView,TVM_INSERTITEM,0,(LPARAM)&tvs);
			tvs.item.pszText = "Item2"; 
			tvs.hParent = hNode1;	//子节点2 
			(HTREEITEM)SendMessage(hTreeView,TVM_INSERTITEM,0,(LPARAM)&tvs);
			
			tvs.item.pszText = "Node2";
			tvs.hParent = NULL;	//根节点2 
			HTREEITEM hNode2 = (HTREEITEM)SendMessage(hTreeView,
				TVM_INSERTITEM,0,(LPARAM)&tvs);
			tvs.item.pszText = "Item3"; 
			tvs.hParent = hNode2;
			(HTREEITEM)SendMessage(hTreeView,TVM_INSERTITEM,0,(LPARAM)&tvs);
			tvs.item.pszText = "Item4"; 
			tvs.hParent = hNode2;
			(HTREEITEM)SendMessage(hTreeView,TVM_INSERTITEM,0,(LPARAM)&tvs);
			

以上，就建立了一个treeView，同时我们也发现了，如果要添加很多个节点，我们的代码会不断的重复，为了代码复用以及方便，我们自己来封装一个类来简化代码。

封装一个类：

class MyTV
{
    public:
		MyTV(HWND hParent)
		{
			hWndTree = hParent;
			m_tvs.item.mask = TVIF_TEXT;
			m_tvs.hInsertAfter = TVI_LAST;
		}
		HTREEITEM Createmy(HTREEITEM hNode, CHAR * str); //添加节点
		
	private:
		TVINSERTSTRUCT m_tvs;
		HWND hWndTree;
			
};
HTREEITEM MyTV::Createmy(HTREEITEM hNode, CHAR * str)
{
	m_tvs.hParent = hNode;
	m_tvs.item.pszText = str;
	HTREEITEM hNode1 = (HTREEITEM)SendMessage
		(hWndTree, TVM_INSERTITEM, 0, (LPARAM)&m_tvs);
    return hNode1;
}

在此基础上，我们对TreeView的添加就非常方便了，结构体被隐藏了，结构体中的每项赋值也给隐藏了：

			MyTV me(hTreeView);
			HTREEITEM hNode1 =  me.Createmy(NULL, "这是根节点1");
			me.Createmy(hNode1, "子节点1"); 
			me.Createmy(hNode1, "子节点2"); 
			me.Createmy(hNode1, "子节点3"); 
			me.Createmy(hNode1, "子节点4"); 
			
			HTREEITEM hNode2 =  me.Createmy(NULL, "这是根节点2");
			me.Createmy(hNode2, "子节点1"); 
			me.Createmy(hNode2, "子节点2"); 
			me.Createmy(hNode2, "子节点3"); 
			me.Createmy(hNode2, "子节点4"); 

程序显示如下：

这样，就可以通过读取文件的层级关系，用树控件显示出来，而且很方便，很迅速。