C# 异步线程加载数据 更新UI

关于多线程的处理，最近用的比较多，所以总结一下：

所谓异步加载数据，就是防止UI主线程加载大量数据（执行太多操作而死掉）。其实很简单，需要用到UI元素的在主线程，后台加载的数据都是与界面无关的。

<span style="font-family: Arial, Helvetica, sans-serif;">加载的数据可以实时反应到UI界面上。其实就是使用了事件的做法</span>

下面是一个例子：

public class ThreadHelper
{
private DirectoryInfo _directory;

private string _searchText;

private Thread _thread = null;

public Action<List<string>> Searching = null;

public Action<List<string>> SearchEnd = null;

private List<string> filelist = new List<string>();

public ThreadHelper(string path,string mess)
{
//构造器，需要什么自己添，一般会传入数据
_directory = new DirectoryInfo(path);
_searchText = mess;
}

public void StartThread()
{
_thread = new Thread(Start);
}

public void Start()
{
Search(_directory);
}

public void Stop()
{
if (_thread != null) _thread.Abort();
if (SearchEnd != null) SearchEnd(filelist);
}

public void Search(DirectoryInfo dir)
{
foreach (var item in dir.GetFileSystemInfos())
{
if (item is FileInfo)
{
FileInfo file = item as FileInfo;
if (!file.GetAccessControl().AreAccessRulesProtected)
{
if (file.Name.Contains(_searchText))
filelist.Add(file.FullName);
}
if (filelist.Count > 10 && Searching != null) Searching(filelist)<span style="color:#ff9900;">;  //重点，每搜找10个则返回数据</span>
}
else if (item is DirectoryInfo)
{
Search(item as DirectoryInfo);
}
}
}
}

public class MainWindow
{
public MainWindow()
{

}
List<string> _list = new List<string>();
List<DispatcherOperation> oplist = new List<DispatcherOperation>();

private void button1_Click(object sender, RoutedEventArgs e)
{
SearchText = textBox1.Text;   //界面的输入框
ThreadHelper helper = new ThreadHelper(@"F:\\", textBox1.Text);
helper.Searching += (args) =>
{
_list.AddRange(args);
DispatcherOperation dp = this.Dispatcher.BeginInvoke((Action)delegate
{
//_list集合放到界面方法   //每次搜索结果都会重新将list集合表现到界面上
}, DispatcherPriority.Background);
oplist.Add(dp);
};
helper.SearchEnd += (args) =>
{
//_list集合放到界面方法
oplist.ForEach(_ => _.Abort());  <span style="color:#ff6600;">//搜索完毕 ，终止所有还在等待执行的界面更新</span>
};
}
}