UI 线程在使用 VS2022 和 Net6.0 异步任务方法上响应进度更新程序的速度很慢

Question

我遇到了性能障碍，我不确定原因，所有这些都是在VS2022 &Net6.0。因为这是我第一次使用模态窗口表单和进度条的这种组合，工作在后台线程上运行，两个进度对象更新UI，进度条和文本标签，我不知道在哪里攻击问题。在将工作负载放在后台线程上之前，一切都很顺利，在大约一分钟内搜索了1000个文件，每个文件中有大约600行文本。当然，windows窗体在此期间被冻结，这就是工作负载被放置在后台线程上的原因。

这样做之后，在UI开始显示Progress对象的值之前，工作负载将完成25-50%，总的来说，整个过程现在需要10倍的时间来完成。进度对象并没有跳过发送给它们的任何值，UI线程只是在获取信息方面显得很慢。同样，如果我试图将模态表单拖到桌面上的一个新位置，它在最终移动之前会有20-30秒没有响应。还有一件事，我可以在后台线程上逐步执行代码，并看到它调用Progress更新程序，但UI线程对它们的响应非常慢。

我可以就如何发现问题提供一些建议，或者如果问题很明显，指出可能的问题在哪里。以下是使用的基本控制和方法。

public class SearchProgressForm : Form
{
private System.Windows.Forms.Button btnSearch = new Button();
private System.Windows.Forms.TextBox txtTextSearch = new TextBox();
private System.Windows.Forms.Label lblSearchFile = new Label();
private System.Windows.Forms.ProgressBar SearchProgressBar = new ProgressBar();
public event LogSearchEventHandler SearchSucceededEvent;
protected void OnSearchSucceeded(LogSearchEventArguments p_eventArguments)
{
LogSearchEventHandler handler = SearchSucceededEvent;
if (handler != null)
{
handler(this, p_eventArguments);
}
}
private void InitializeComponent()
{
this.btnSearch.Name = "btnSearch";
this.btnSearch.Text = "Search";
this.btnSearch.Click += new System.EventHandler(this.btnSearch_Click);
this.lblSearchFile.Text = "Searching File: ";
this.txtTextSearch.Text = "search string";
}
public SearchProgressForm() { }
private void btnSearch_Click(object sender, EventArgs e)
{
this.SearchByText(this.txtTextSearch.Text);
}
private void SearchByText(string p_searchParameter)
{
// Setup a progress report for thr ProgressBar
var _progressBarUpdate = new Progress<int>(value =>
{
this.SearchProgressBar.Value = value;
this.SearchProgressBar.Refresh();
});
var _progressFileNameUpdate = new Progress<string>(value =>
{
this.lblSearchFile.Text = "Searching File For : " + value;
this.lblSearchFile.Refresh();
});
// Start search on a backgroud thread and report progress as it occurs
Task.Run(async () => await this.SearchByStringAsync(p_searchParameter, _progressBarUpdate, _progressFileNameUpdate));
}
private async Task SearchByStringAsync(string p_searchParameter, IProgress<int> p_progressBar, IProgress<string> p_progressFileName)
{
await Task.Delay(1);
TextFileReader textFileReader = new TextFileReader();
LogSearchEventArguments logSearchEventArguments = null;
long _sessionloopCount = 0;
long _totalTextLinesCount = this.GetTotalSearchCount(p_searchParameter, SearchType.TextString);

// Get file names from SQL table
var _logFiles = DataOperations.LogFileSortableList(null);
foreach (var log in _logFiles)
{
// Format a file name to be read from the file system
string _fileName = log.Directory + "\" + log.FileName;
p_progressFileName.Report(log.FileName);
// If we've raised an event for this file, then stop iterating over remaning text
if (logSearchEventArguments != null)
{
logSearchEventArguments = null;
break;
}
// Read in file contents from file system
List<string> _fileContents = textFileReader.ReadAndReturnStringList(_fileName);
long _fileTotalRecordCount = _fileContents.Count;
long _fileRecordCount = 0;
foreach (var _line in _fileContents)
{
if (_line.ToUpper().Contains(p_searchParameter.ToUpper()))
{
// Raise an event so search parameter and file name can be captured in another form
logSearchEventArguments =
new LogSearchEventArguments
(
"TextSearch", p_searchParameter, SearchType.TextString, true, log,
new DateTime(
Convert.ToInt32("20" + log.FileName.Substring(14, 2)),
Convert.ToInt32(log.FileName.Substring(16, 2)),
Convert.ToInt32(log.FileName.Substring(18, 2)))
);
// We found a match, so no further searching is needed in this log file,
// and it's been flagged in the DB, so raise the event to save search parameter and file name
// then break out of this loop to get the next file to search in.
this.OnSearchSucceeded(logSearchEventArguments);
break;
}
// These calcs are based on actual searches performed
_fileRecordCount++;
_sessionloopCount++;
p_progressBar.Report(Convert.ToInt32((_sessionloopCount * 100) / _totalTextLinesCount));
}
// Because we exit a search as soon as the 1st match is made, need to resynch all counts
// and update the progress bar accordingly
if (_fileRecordCount < _fileTotalRecordCount)
{
long _countDifference = _fileTotalRecordCount - _fileRecordCount;
// Add count difference to sessionLoopCount and update progress bar
_sessionloopCount += _countDifference;
p_progressBar.Report(Convert.ToInt32((_sessionloopCount * 100) / _totalTextLinesCount));
}
}
//Search is complete set Progress to 100% and report before exiting
p_progressBar.Report(100);
// Close the modal SearchForm and exit
this.Close();
}
}

Answer 1

我解决了这个问题，但我仍然不确定是什么原因造成的。我取消了方法"private void SearchByText(string p_searchParameter)"并将代码移动到btnSearch_Click事件处理程序中，这样我就可以调用后台工作器SearchByStringAsync"直接从按钮点击事件处理程序。

我还更新了EFCore NuGet包，版本Net6.0到版本6.0.4，因为我的Async后台方法中的一行代码"var _logFiles = DataOperations.LogFileSortableList(null)"。

该调用返回一个Sortable BindingList，使用BindingList。在NuGet更新和我的BindingList中自定义比较器方法的一个小变化之间类后，windows模态表单现在按预期更新ProgressBar和Label文本，并且表单现在立即响应用户交互。