兄弟我找到解决方法了在treeview.htc文件中
把函数function doNodeClick(el)
中的
function doNodeClick(el)
{
if (g_bInteractive == false)
return;
g_nodeClicked = el;
// The element, which is in a content node outside of the document, is outside the event hierarchy.
// Fire the event ourselves, rather than relying on bubbling.
event.cancelBubble = true;
el.fireEvent("onclick"); // Execute our onclick handler
element.fireEvent("onclick", event); // Execute the tree's onclick handler
if (getNodeAttribute(el, "NavigateUrl") != null)
{
var target = getNodeAttribute(el, "Target");
// if (target == null || target.toLowerCase() == "_self")
// return false;
}