树型展开不提交，点击提交的实现方法：
1.将autopostback的属性值设置为false；
2.在body里添加 <body onload="initTree()">
在PageLoad中添加如下代码：
string strTreeName = "TreeView1";
string strRef = Page.GetPostBackEventReference(TreeView1);
string strScript = "<script language=\"JavaScript\"> \n" + "<!-- \n" + " function initTree() { \n" +" " + strTreeName + ".onSelectedIndexChange = function() { \n"
+ "if (event.oldTreeNodeIndex != event.newTreeNodeIndex) \n" + "this.queueEvent('onselectedindexchange', event.oldTreeNodeIndex + ',' + event.newTreeNodeIndex); \n"
+ "window.setTimeout('" + strRef.Replace("'","\\'") + "', 0, 'JavaScript'); \n" + " } \n" + " } \n" + "// --> \n" + "</script>";
Page.RegisterClientScriptBlock("InitTree",strScript );
string strRef = Page.GetPostBackEventReference(TreeView1);
string strScript = "<script language=\"JavaScript\"> \n" + "<!-- \n" + " function initTree() { \n" +" " + strTreeName + ".onSelectedIndexChange = function() { \n"
+ "if (event.oldTreeNodeIndex != event.newTreeNodeIndex) \n" + "this.queueEvent('onselectedindexchange', event.oldTreeNodeIndex + ',' + event.newTreeNodeIndex); \n"
+ "window.setTimeout('" + strRef.Replace("'","\\'") + "', 0, 'JavaScript'); \n" + " } \n" + " } \n" + "// --> \n" + "</script>";
Page.RegisterClientScriptBlock("InitTree",strScript );