Question

我正在使用BackGroundWorker类在sqlserver中插入一些值。我在这里循环插入值。我正在使用以下代码

 public void bw_Convert_DoWork(object sender, DoWorkEventArgs e)
    {           
        e.Result = e.Argument;
        for (int i = 0; i <  fTable.Rows.Count; i++)
        {
            try
            {
                SqlCommand cmd = new SqlCommand("INSERT INTO TBL_CDR_ANALYZER (LNG_UPLOAD_ID, DAT_START, LNG_DURATION, INT_DIRECTION, INT_CALL_DATA_TYPE, \n" +
                    "TXT_TARGET_NUMBER, TXT_OTHER_PARTY_NUMBER, TXT_TARGET_IMSI, TXT_TARGET_IMEI, TXT_TARGET_CELL_ID, TXT_ROAMING_NETWORK_COMPANY_NAME) VALUES \n" +
                    "(@UPLOAD_ID, @START_DATE, @DURATION, @DIRECTION, @CALL_TYPE, @TARGET_NUMBER, @OTHER_PARTY_NUMBER, @IMSI, @IMEI, @CELL_ID, @ROAMING_NAME)", sqlCon);
                cmd.Parameters.Add("@UPLOAD_ID", SqlDbType.Int).Value = 1;
                cmd.Parameters.Add("@START_DATE", SqlDbType.DateTime).Value = fTable.Rows[i]["CallDate"];
                cmd.Parameters.Add("@DURATION", SqlDbType.Int).Value = fTable.Rows[i]["CallDuration"];
                cmd.Parameters.Add("@DIRECTION", SqlDbType.Int).Value = GetCallDirection(fTable.Rows[i]["CallDirection"].ToString());
                cmd.Parameters.Add("@CALL_TYPE", SqlDbType.Int).Value = GetCallType(fTable.Rows[i]["CallType"].ToString());
                cmd.Parameters.Add("@TARGET_NUMBER", SqlDbType.VarChar, 25).Value = fTable.Rows[i]["TargetNo"];
                cmd.Parameters.Add("@OTHER_PARTY_NUMBER", SqlDbType.VarChar, 25).Value = fTable.Rows[i]["OtherPartyNo"];
                cmd.Parameters.Add("@IMSI", SqlDbType.VarChar, 50).Value = fTable.Rows[i]["IMSI"];
                cmd.Parameters.Add("@IMEI", SqlDbType.VarChar, 50).Value = fTable.Rows[i]["IMEI"];
                cmd.Parameters.Add("@CELL_ID", SqlDbType.VarChar, 50).Value = fTable.Rows[i]["CellID"];
                cmd.Parameters.Add("@ROAMING_NAME", SqlDbType.NVarChar, 255).Value = fTable.Rows[i]["RoamingCompany"];
                sqlCon.Open();
                cmd.ExecuteNonQuery();
                sqlCon.Close();
            }
            catch (SqlException ex)
            {

            }
            finally
            {
                sqlCon.Close();
            }
            bw_Convert.ReportProgress((100 * i) / fTable.Rows.Count);  
            **Label1.Text = i.ToString() + "Files Converted";** // getting error Here.                  
        }    
    }

如何更新Label1文本

Answer 1

这应该可以从后台线程更改GUI。

Label1.Invoke((MethodInvoker)delegate {
   Label1.Text = i.ToString() + "Files Converted";});

Answer 2

您无法像DoWork方法中的标签那样访问UI界面对象 DoWork在与UI元素不同的线程上运行您需要通过ProgressChanged事件更新界面或调用委托。

首先将BackgroundWorker的WorkerReportsProgress属性设置为True，然后，对ReportProgress方法的调用将引发将在您的界面元素的同一个线程中运行的事件ProgressChanged

private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
     Label1.Text = e.ProgressPercentage.ToString();
}

Answer 3

您必须实施ProgressChanged-Event。

private void bw_Convert_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
   //The progress in percentage
   int progress = e.ProgressPercentage;
   //A custom-value you can pass by calling ReportProgress in DoWork
   object obj = e.UserState;
}

Answer 4

//您也可以尝试更新标签

this.Invoke(new MethodInvoker(delegate 
          {
             Label1.Text = i.ToString() + "Files Converted";
          }));

Answer 5

我遇到了同样的问题。我已经在“更改进度的后台工作人员事件”中，但是即使同时使用上述两个版本的“方法调用程序”也无济于事。然后我尝试了一下，它就起作用了：

public enum Genders { male, female, other }

class student
{
    public string Name;
    public int Age;
    public Genders Gender;

    public void Write()
    {
        Console.WriteLine("Name: {0}, Age: {1}, Gender: {2}", Name, Age, Gender.ToString());
    }
}

 class Program
{
    static void Main(string[] args)
    {
        student student1 = new student();
        student1.Name = "Dan";
        student1.Age = 15;
        student1.Gender = Genders.male;
        student1.Write();
    }
}

更新背景工人winforms中的标签文本

5 个答案: