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page_load中的调用方法导致adapter.fill()上出现StackOverflowException,但在其他地方调用时没有问题

sql-server asp.net

Hua Deng · 技术社区 · 1 年前

我现在很困惑。我有多个从sql连接绑定gridview的方法。

当我从下拉索引中调用这些更改时,它运行良好。

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
  int machineid = int.Parse(DropDownList1.SelectedValue);
  try { 
  connection.Open();
  EquimentBind(machineid);
      
  }
 
  finally { connection.Close(); }

}

但是,当我从page_load调用方法并从URL传递id时,它总是在adapter.fill(dataTable)步骤中给我StackOverflowException。

 protected void Page_Load(object sender, EventArgs e)
    {
  

  if (!IsPostBack)
      {
    string station_id = Request.QueryString["station_id"];
   

    if (station_id != null)
        {
         
      DropDownList1.Visible = false;
      int machineid = int.Parse(station_id);
      try
      {
        if (connection.State != ConnectionState.Open)
        {
          connection.Open();
        }
        EquimentBind(machineid);
       
      }

      finally { connection.Close(); }
    }   
        else
        {
         
          try
            {
              if (connection.State != ConnectionState.Open) { connection.Open(); }
              SqlDataAdapter adapter = //My sql command
              DataTable stalist = new DataTable();
              adapter.Fill(stalist);
              DropDownList1.DataSource = stalist;
              DropDownList1.DataTextField = "name";
              DropDownList1.DataValueField = "Id";
              DropDownList1.DataBind();

            }

            finally { connection.Close(); }
            DropDownList1.SelectedValue = Convert.ToString('0');

      
        }
        
       

      }

以下是我的数据绑定方法:

 protected void EquimentBind(int machineid)
{
  

 
  SqlCommand Sqlcommand = // my sql command
  SqlCommand command = Sqlcommand;
  SqlDataAdapter sd = new SqlDataAdapter(command);
  DataTable dt1 = new DataTable();
  sd.Fill(dt1);
  GV_Equipments.DataSource = dt1;
  GV_Equipments.DataBind();
  command.ExecuteNonQuery();
  dt1.Clear();
 

}

StackOverflowExec选项总是在sd.Fill(dt1)行引发。

我做错了什么?

0 回复 | 直到 1 年前

Matt 1 年前

StackOverflowException可能是因为EquimentBind方法在无限循环中被递归调用。当由于数据绑定过程导致回发而重复触发Page_Load事件时,可能会发生这种情况。

当station_id为null时,从Page_Load事件中删除数据绑定逻辑,因为这是不必要的,并且会导致递归调用。您可以简化Page_Load事件,如下所示:

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        string station_id = Request.QueryString["station_id"];

        if (station_id != null)
        {
            DropDownList1.Visible = false;
            int machineid = int.Parse(station_id);
            try
            {
                if (connection.State != ConnectionState.Open)
                {
                    connection.Open();
                }
                EquimentBind(machineid);
            }
            finally
            {
                connection.Close();
            }
        }
        else
        {
            try
            {
                if (connection.State != ConnectionState.Open)
                {
                    connection.Open();
                }
                SqlDataAdapter adapter = //My sql command
                DataTable stalist = new DataTable();
                adapter.Fill(stalist);
                DropDownList1.DataSource = stalist;
                DropDownList1.DataTextField = "name";
                DropDownList1.DataValueField = "Id";
                DropDownList1.DataBind();
            }
            finally
            {
                connection.Close();
            }
            DropDownList1.SelectedValue = "0";
        }
    }
}

修改DropDownList1_SelectedIndexChanged事件以处理这两种情况,即当从下拉列表更改选择时和从URL加载选择时:

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
    int machineid = int.Parse(DropDownList1.SelectedValue);
    try
    {
        connection.Open();
        EquimentBind(machineid);
    }
    finally
    {
        connection.Close();
    }
}