c# - UI 对长时间的 for 循环 react 迟钝

Question

我有一个 WinForm 应用程序，它使用 Spreadsheetlight 从 excel 文件读取数据，有一种方法可以读取信息然后进行一些计算，然后我创建一个新的 excel 文件。

问题是这个文件有大约 100,000 条记录，我在 UI 中有一个标签，我想在每次读取 excel 行时更新它，但标签似乎没有响应；

 public List<DataRow> GeExcelData(string filePath)
 {
    var myTable = new List<DataRow>();
    int row = 0;

    using (var input = new SLDocument(filePath))
    {
        SLWorksheetStatistics stats = input.GetWorksheetStatistics();
        int iStartColumnIndex = stats.StartColumnIndex;

        progressBar1.Minimum = 0;
        progressBar1.Maximum = stats.EndRowIndex;
        progressBar1.Step = 1;

        for (row = stats.StartRowIndex + 1; row <= stats.EndRowIndex; ++row)
        {
            //Here is the label
            lblStatus.Text = "Reading row " + row + " of " + stats.EndRowIndex;

            var dataRowTmp = new DataRow()
            {
                name = input.GetCellValueAsString(row, iStartColumnIndex),
                sku = input.GetCellValueAsString(row, iStartColumnIndex + 1),
                value2 = input.GetCellValueAsString(row, iStartColumnIndex + 2),
                value3 = input.GetCellValueAsString(row, iStartColumnIndex + 3)
            };

            progressBar1.PerformStep();
            myTable.Add(dataRowTmp);
        }

        lblStatus.Text = "";
        progressBar1.Value = 0;
    }

    return myTable;
}

有没有办法在执行一些长时间运行的任务时有效地更新 UI。因为只是一个标签我不想写一些复杂的代码。我还有运行良好的 progressBar1。

Answer 1

尝试这段代码，声明将在主线程上更新控件的委托(delegate)方法，查看下面的实现，

delegate void SetStatus(string value);
delegate void SetProgress(int value);

启动一个线程来处理数据和更新控件，

Thread t  = new Thread(StartProc);
t.Start();


public void StartProc()
{
  using (var input = new SLDocument(filePath))
  {
    SLWorksheetStatistics stats = input.GetWorksheetStatistics();

    int iStartColumnIndex = stats.StartColumnIndex;
    for (row = stats.StartRowIndex + 1; row <= stats.EndRowIndex; ++row)
    {
        int percent = (row+1)*100/stats.EndRowIndex;
        //Here is the label
        setStatus("Reading row " + row + " of " + stats.EndRowIndex);
        var dataRowTmp = new DataRow()
        {
            name = input.GetCellValueAsString(row, iStartColumnIndex),
            sku = input.GetCellValueAsString(row, iStartColumnIndex + 1),
            value2 = input.GetCellValueAsString(row, iStartColumnIndex + 2),
            value3 = input.GetCellValueAsString(row, iStartColumnIndex + 3)
        };
        setProgress(percent);
        myTable.Add(dataRowTmp);

    }
    setStatus("");
    setProgress(0);
  }
}
private void SetStatus(string value)
{
  if (this.InvokeRequired)
  {
    SetStatusDelg dlg = new SetStatusDelg(this.SetStatus);
    this.Invoke(value);
    return;
  }
  lblStatus.Text = value;
}
private void SetProgress(int value)
{
  if (this.InvokeRequired)
  {
    SetProgressDelg dlg = new SetProgressDelg(this.SetStatus);
    this.Invoke(value);
    return;
  }
  progressBar1.value = value;
}