/// <summary>
/// 重置一个节点
/// </summary>
/// <param name="tn"></param>
/// <param name="acbCallback"></param>
/// <param name="state"></param>
private void ReLoadNode(TreeNode tn, AsyncCallback acbCallback = null, object state = null)
{
FileType ft = FileType.磁盘;
var mytag = tn.Tag as myNodeTag;
if (mytag != null)
{
ft = mytag.FileType;
}
var parent = tn.Parent;
var idx = tn.Index;
tn.Remove();
tn.Nodes.Clear();
if (acbCallback == null)
{
state = tn;
acbCallback = ar =>
{
if (parent == null)
{
SetNodeIdx(tn, 3);
}
else
{
AddChildNode(parent, tn, ft == FileType.文件, idx);
}
};
}
if (ft == FileType.文件)
{
var fi = ((tn.Tag as myNodeTag).Tag as FileInfo);
fi.Refresh();
if (!fi.Exists)
{
ReLoadNode(parent);//不存在就刷新父节点
return;
}
AddChildNode(parent, tn, ft == FileType.文件, idx);
return;
}
GetInDirectoryFiles handler = new GetInDirectoryFiles(GetInDirectoryFiles);
IAsyncResult result = handler.BeginInvoke(tn, acbCallback, state);
}
private async void 加载子节点(List <TreeNode> tns, bool 使用ui线程 = false)
{
GetInDirectoryFiles handler = new GetInDirectoryFiles(GetInDirectoryFiles);
//IAsyncResult: 异步操作接口(interface)
//BeginInvoke: 委托(delegate)的一个异步方法的开始
// 委托参数，回调函数，回调函数中的result.AsyncState对象
if (!使用ui线程)
{
handler.BeginInvoke(tns[0], new AsyncCallback(异步回调函数), tns); //后台线程异步
return;
}
while (tns.Count > 0)
{
await GetInDirectoryFiles(tns[0]);//主线程上异步
真回调函数(tns);
}
}
private void 异步回调函数(IAsyncResult result)
{
try
{
//result 是委托方法的返回值
//AsyncResult 是IAsyncResult接口的一个实现类，空间：System.Runtime.Remoting.Messaging
//AsyncDelegate 属性可以强制转换为用户定义的委托的实际类。
GetInDirectoryFiles handler = null;
if (result != null)
{
handler = (GetInDirectoryFiles)((AsyncResult)result).AsyncDelegate;
handler.EndInvoke(result).Wait();
}
// Console.WriteLine(result.AsyncState);
var curNodes = (result.AsyncState as List <TreeNode>);
真回调函数(curNodes);
IAsyncResult result1 = handler.BeginInvoke(curNodes[0], new AsyncCallback(异步回调函数), curNodes);
}
catch (Exception)
{
}
}
