Question

在doowrk活动中：

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            BackgroundWorker worker = sender as BackgroundWorker;
            _stopwatch.Restart();
            DirSearch(@"d:\c-sharp", "*.cs", "Form1");
            _stopwatch.Stop();
        }

问题是我在dowork事件中调用DirSearch所以我无法将工作者传递给DirSearch。

如果我将工作人员传递给DirSearch，那么我需要在DirSearch中做：

if (worker.CancellationPending == true)
                {
                    e.Cancel = true;
                    break;
                }

但是DirSearch中不存在e。

private void DirSearch(string root, string filesExtension,string textToSearch)
        {
            int numberoffiles = 0;
            int numberofdirs = 0;
            string[] filePaths = Directory.GetFiles(root, filesExtension, SearchOption.AllDirectories);
            for (int i = 0; i < filePaths.Length; i++)
            {
                List<MyProgress> prog = new List<MyProgress>();
                int var = File.ReadAllText(filePaths[i]).Contains(textToSearch) ? 1 : 0;
                if (var == 1)
                {
                    string filename = filePaths[i];
                    numberoffiles ++;
                    prog.Add(new MyProgress { Report1 = filename, Report2 = numberoffiles.ToString() });
                    backgroundWorker1.ReportProgress(0, prog);
                    Thread.Sleep(100);
                }
                numberofdirs ++;
                label1.Invoke((MethodInvoker)delegate
                            {
                                label1.Text = numberofdirs.ToString();
                                label1.Visible = true;
                            });
            }
        }

Answer 1

如果您想使用BackgroundWorker，则需要将BackgroundWorker和private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) { BackgroundWorker worker = sender as BackgroundWorker; _stopwatch.Restart(); DirSearch(@"d:\c-sharp", "*.cs", "Form1", worker, e); _stopwatch.Stop(); } private void DirSearch(string root, string filesExtension,string textToSearch, BackgroundWorker worker, DoWorkEventArgs e) { int numberoffiles = 0; int numberofdirs = 0; string[] filePaths = Directory.GetFiles(root, filesExtension, SearchOption.AllDirectories); for (int i = 0; i < filePaths.Length; i++) { if (worker.CancellationPending == true) { e.Cancel = true; return; } List<MyProgress> prog = new List<MyProgress>(); int var = File.ReadAllText(filePaths[i]).Contains(textToSearch) ? 1 : 0; if (var == 1) { string filename = filePaths[i]; numberoffiles ++; prog.Add(new MyProgress { Report1 = filename, Report2 = numberoffiles.ToString() }); backgroundWorker1.ReportProgress(0, prog); Thread.Sleep(100); } numberofdirs ++; label1.Invoke((MethodInvoker)delegate { label1.Text = numberofdirs.ToString(); label1.Visible = true; }); } }传递给您的函数。

Task.Run

这是使用async / await和CancellationTokenSource source = new CancellationTokenSource(); private async Task SearchDirectories() { if (source != null) { //Cancel the previously running instance. source.Cancel(); } source = new CancellationTokenSource(); var foundProgress = new Progress<MyProgress>(/* Some code here*/); var totalProgress = new Progress<int>(numberofdirs => { label1.Text = numberofdirs.ToString(); label1.Visible = true; }); try { _stopwatch.Restart(); await Task.Run(() => DirSearch(@"d:\c-sharp", "*.cs", "Form1", source.Token, foundProgress, totalProgress), source.Token); _stopwatch.Stop(); //Do any code here you had in BackgroundWorker.RunWorkerCompleted } catch (OperationCanceledException) { //Do any special code here if it was canceled. } } private void DirSearch(string root, string filesExtension, string textToSearch, CancellationToken token, IProgress<MyProgress> foundProgress, IProgress<int> totalProgress) { int numberoffiles = 0; int numberofdirs = 0; string[] filePaths = Directory.GetFiles(root, filesExtension, SearchOption.AllDirectories); for (int i = 0; i < filePaths.Length; i++) { token.ThrowIfCancellationRequested(); int var = File.ReadAllText(filePaths[i]).Contains(textToSearch) ? 1 : 0; if (var == 1) { string filename = filePaths[i]; numberoffiles++; var prog = new MyProgress { Report1 = filename, Report2 = numberoffiles.ToString() }; foundProgress.Report(prog); } numberofdirs++; totalProgress.Report(numberofdirs); } }

的快速重新解释

StringBuilder strData = new StringBuilder();
ReferenceDocument.SaveCopyAs(strSomeTempFile);
var cnnStr = String.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended properties=\"Excel 8.0;IMEX=1;HDR=NO\"", strSomeTempFile);
var cnn = new OleDbConnection(cnnStr);
try
{
    cnn.Open();
    var schemaTable = cnn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
    foreach(DataRow schemaRow in schemaTable.Rows)
    {
        string worksheetName = schemaRow["table_name"].ToString().Replace("'", "");
        string sql = String.Format("select * from [{0}]", worksheetName);
        var da = new OleDbDataAdapter(sql, cnn);
        var dt = new DataTable();
        da.Fill(dt);
        foreach (DataRow row in dt.Rows)
        foreach (DataColumn col in dt.Columns)
        {
            var value = row[col.ColumnName];
            if (!(value is System.DBNull)) strData.AppendLine(value.ToString());
        }
    }
}
catch (Exception e)
{
    // handle error
    throw;
}
finally
{
    cnn.Close();
}
return strData;

我如何取消/停止背景工作者？

1 个答案: