如果我将列表移动到新线程，则无法填充它
如果我将列表移动到新线程，则无法填充它
提问于 2013-01-02 12:34:24
我使用SafeFileEnumerator类来搜索文件夹根目录中的文件，这个类只在有权限的情况下从位置返回文件，所以我正在成功地使用它。
当我试图以这种方式填写我的列表时，一切都很好：
List<string> list = new List<string>();
list = SafeFileEnumerator.EnumerateFiles(folderBrowserDialog1.SelectedPath,
"*.*", SearchOption.AllDirectories).ToList();但是在这种情况下，我的GUI冻结了，所以我将它移动到新线程，在这种情况下什么也没有发生，我想知道为什么：
private void btnAddDir_Click(object sender, EventArgs e)
{
List<string> list = new List<string>();
string fileToAdd = string.Empty;
List<string> filesList = new List<string>();
dialog = folderBrowserDialog1.ShowDialog();
tbAddDir.Text = folderBrowserDialog1.SelectedPath;
string pathToSearch = folderBrowserDialog1.SelectedPath;
if (dialog == DialogResult.OK)
{
toolStripStatusLabel.Text = "Search for pcap files...";
groupBoxRootDirectory.Enabled = false;
btnStart.Enabled = false;
ThreadStart starter = delegate
{
list = SafeFileEnumerator.EnumerateFiles(pathToSearch, "*.pcap", SearchOption.AllDirectories).ToList();
};
Thread t = new Thread(starter);
t.IsBackground = true;
t.Start();
if(list.Count != 0)
AddFilesToListBox(list);
}
}SafeFileEnumerator类代码：
public static class SafeFileEnumerator
{
public static IEnumerable<string> EnumerateDirectories(string parentDirectory, string searchPattern, SearchOption searchOpt)
{
try
{
var directories = Enumerable.Empty<string>();
if (searchOpt == SearchOption.AllDirectories)
{
directories = Directory.EnumerateDirectories(parentDirectory).SelectMany(x => EnumerateDirectories(x, searchPattern, searchOpt));
}
return directories.Concat(Directory.EnumerateDirectories(parentDirectory, searchPattern));
}
catch (UnauthorizedAccessException ex)
{
return Enumerable.Empty<string>();
}
}
public static IEnumerable<string> EnumerateFiles(string path, string searchPattern, SearchOption searchOpt)
{
try
{
var dirFiles = Enumerable.Empty<string>();
if (searchOpt == SearchOption.AllDirectories)
{
dirFiles = Directory.EnumerateDirectories(path).SelectMany(x => EnumerateFiles(x, searchPattern, searchOpt));
}
return dirFiles.Concat(Directory.EnumerateFiles(path, searchPattern));
}
catch (UnauthorizedAccessException ex)
{
return Enumerable.Empty<string>();
}
}
}在我的名单上满是文件之后：
private void AddFilesToListBox(List<string> filesList)
{
string fileToAdd = string.Empty;
Editcap editcap = new Editcap();
Capinfos capinfos = new Capinfos();
BackgroundWorker backgroundWorker = new BackgroundWorker();
backgroundWorker.WorkerReportsProgress = true;
backgroundWorker.DoWork +=
(s1, e1) =>
{
foreach (string fileName in filesList)
{
FileInfo fileInfo = new FileInfo(fileName);
if (checkFileCreationDate(fileInfo))
{
if (editcap.isWiresharkFormat(fileInfo.FullName))
{
if (editcap.isLibpcapFormat(fileInfo.FullName))
{
addFileToListBox(fileInfo.FullName, capinfos.getFileDuration(fileInfo.FullName));
}
else if (!editcap.isLibpcapFormat(fileInfo.FullName))
{
fileToAdd = editcap.getNewFileName(fileInfo.FullName);
if (new FileInfo(fileToAdd).Exists && !fileInfo.Exists)
{
addFileToListBox(fileToAdd, capinfos.getFileDuration(fileInfo.FullName));
}
}
}
}
//this.Invoke((MethodInvoker)delegate { lvFiles.Items[lvFiles.Items.Count - 1].Selected = true; });
toolStripStatusLabel.Text = string.Format("{0} files were added", lvFiles.Items.Count);
}
//this.Invoke((MethodInvoker)delegate { lvFiles.Items[lvFiles.Items.Count - 1].Selected = true; });
};
backgroundWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(
(s1, e1) =>
{
groupBoxRootDirectory.Enabled = true;
btnClear.Enabled = true;
if (lvFiles.Items.Count != 0)
btnStart.Enabled = true;
toolStripStatusLabel.Text = string.Format("{0} files were added", lvFiles.Items.Count);
if (tbAddDir.Text != "")
{
listener = new FileListener();
listener.startListener(tbAddDir.Text);
listener._newFileEventHandler += listener_newFileEventHandler;
}
});
backgroundWorker.RunWorkerAsync();
}回答 1
Stack Overflow用户
回答已采纳
发布于 2013-01-02 13:04:20
在t.start()之后，我调用AddFilesToListBox(列表)；
您没有实现异步模式。
在调用t.Start();之后，线程还没有完成它的工作，所以在调用AddFilesToListBox时，您的列表仍然是空的。实现异步模式，并在线程完成任务后调用AddFilesToListBox。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/14122140
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