错误：无法将字符串转换为int32在调试

Question

我有一个测试gridview设置与编辑模板为我的用户能够编辑/更新/添加几个记录。下面是测试的样子：

当我打更新编辑，更改值，然后单击更新值不更新。当我把一个断点上的更新语句它指向的数据表中记载：

private int InpatientMeasures = 1; 
private int OutpatientMeasures = 2; 

private int HeartAttack = 1; 
private int HeartFailure = 2; 
private int Pneumonia = 3; 
private int SIPrevention = 4; 
private int Surgery = 5; 

下面是数据表： failed to convert string to int32

名单如下定义

private DataTable GetData(SqlCommand cmd) 
{ 
    DataTable dt = new DataTable(); 
    SqlConnection con = new SqlConnection(conn); 
    SqlDataAdapter sda = new SqlDataAdapter(); 
    cmd.CommandType = CommandType.Text; 
    cmd.Connection = con; 
    con.Open(); 
    sda.SelectCommand = cmd; 
    sda.Fill(dt); //This is where it breaks and gives the error in debug mode 
    return dt; //The Code will actually work until the line above but will not reach here 
} 

的调试将不会指定什么int。我也将@num变量值转换为一个int值，但它仍然不会更新。

protected void UpdateQualityMeasures(object sender, GridViewUpdateEventArgs e) 
{ 
    string Mynum = ((Label)gvMainView.FooterRow.FindControl("lblNum")).Text; 
    string SiteID = ((DropDownList)gvMainView.FooterRow.FindControl("ddlSite")).Text; 
    switch (SiteID) 
    { 
     case "Inpatient Measures": 
      SiteID = InpatientMeasures.ToString(); 
      break; 
     case "Outpatient Measures": 
      SiteID = OutpatientMeasures.ToString(); 
      break; 
    } 

    string ServiceLineID = ((DropDownList)gvMainView.FooterRow.FindControl("ddlServiceLine")).Text; 
    switch (ServiceLineID) 
    { 
     case "Heart Attack": 
      ServiceLineID = HeartAttack.ToString(); 
      break; 
     case "Heart Failure": 
      ServiceLineID = HeartFailure.ToString(); 
      break; 
     case "Pneumonia": 
      ServiceLineID = Pneumonia.ToString(); 
      break; 
     case "Surgical Infection Prevention": 
      ServiceLineID = SIPrevention.ToString(); 
      break; 
     case "Surgery": 
      ServiceLineID = Surgery.ToString(); 
      break; 
    } 


    string Measure = ((TextBox)gvMainView.FooterRow.FindControl("txtMeasure")).Text; 
    string MyCompAvg = ((TextBox)gvMainView.FooterRow.FindControl("txtMyCompAvg")).Text; 
    string NationalAvg = ((TextBox)gvMainView.FooterRow.FindControl("txtNationalAvg")).Text; 
    string KYStateAvg = ((TextBox)gvMainView.FooterRow.FindControl("txtKYStateAvg")).Text; 

    SqlConnection con = new SqlConnection(conn); 
    SqlCommand cmd = new SqlCommand(); 
    cmd.CommandType = CommandType.Text; 
    string QueryPartB = Measures; 
    int NewID = Convert.ToInt32(Mynum); 

    cmd.CommandText = "update quality_Measures set SiteID=@SiteID, ServiceLineID=@ServiceLineID, Measure=@Measure, MyCompAvg=@MyCompAvg, KYStateAvg=@KYStateAvg, NationalAvg=@NationalAvg where " + 
    "num=@num;" + QueryPartB; 
    cmd.Parameters.Add("@num", SqlDbType.Int).Value = NewID; 
    cmd.Parameters.Add("@SiteID", SqlDbType.NVarChar).Value = SiteID; 
    cmd.Parameters.Add("@ServiceLineID", SqlDbType.NVarChar).Value = ServiceLineID; 
    cmd.Parameters.Add("@Measure", SqlDbType.NText).Value = Measure; 
    cmd.Parameters.Add("@MyCompAvg", SqlDbType.NVarChar).Value = MyCompAvg; 
    cmd.Parameters.Add("@KYStateAvg", SqlDbType.NVarChar).Value = KYStateAvg; 
    cmd.Parameters.Add("@NationalAvg", SqlDbType.NVarChar).Value = NationalAvg; 
    gvMainView.EditIndex = -1; 
    gvMainView.DataSource = GetData(cmd); 
    gvMainView.DataBind(); 
} 

你会发现存在这样说QueryPartB变量设置数据表回更新后的影像中选择更新的地方。

编辑 - 这里是请求堆栈跟踪

at System.Data.SqlClient.SqlParameter.CoerceValue(Object value, MetaType destinationType, Boolean& coercedToDataFeed, Boolean& typeChanged, Boolean allowStreaming) 
at System.Data.SqlClient.SqlParameter.GetCoercedValue() 
at System.Data.SqlClient.SqlParameter.Validate(Int32 index, Boolean isCommandProc) 
at System.Data.SqlClient.SqlCommand.BuildParamList(TdsParser parser, SqlParameterCollection parameters) 
at System.Data.SqlClient.SqlCommand.BuildExecuteSql(CommandBehavior behavior, String commandText, SqlParameterCollection parameters, _SqlRPC& rpc) 
at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite) 
at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite) 
at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) 
at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) 
at System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) 
at System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior) 
at System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior) 
at System.Data.Common.DbDataAdapter.Fill(DataTable[] dataTables, Int32 startRecord, Int32 maxRecords, IDbCommand command, CommandBehavior behavior) 
at System.Data.Common.DbDataAdapter.Fill(DataTable dataTable) 
at QualityOutcomeGraphGen_test.Admin.GetData(SqlCommand cmd) in c:\Users\20002143\Documents\Visual Studio 2012\Projects\QualityOutcomeGraphGen_test\QualityOutcomeGraphGen_test\Admin.aspx.cs:line 57 
at QualityOutcomeGraphGen_test.Admin.UpdateQualityMeasures(Object sender, GridViewUpdateEventArgs e) in c:\Users\20002143\Documents\Visual Studio 2012\Projects\QualityOutcomeGraphGen_test\QualityOutcomeGraphGen_test\Admin.aspx.cs:line 241 
at System.Web.UI.WebControls.GridView.OnRowUpdating(GridViewUpdateEventArgs e) 
at System.Web.UI.WebControls.GridView.HandleUpdate(GridViewRow row, Int32 rowIndex, Boolean causesValidation) 
at System.Web.UI.WebControls.GridView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup) 
at System.Web.UI.WebControls.GridView.OnBubbleEvent(Object source, EventArgs e) 
at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) 
at System.Web.UI.WebControls.GridViewRow.OnBubbleEvent(Object source, EventArgs e) 
at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) 
at System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e) 
at System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) 
at System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) 
at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) 
at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) 
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) 

Answer 1

我需要找到该行。因此，我改变

string Mynum = ((Label)gvMainView.FooterRow.FindControl("lblNum")).Text; 

要

string Mynum = ((Label)gvMainView.Rows[e.RowIndex].FindControl("lblNum")).Text; 

和现在的作品！

Answer 2

看来你NewID变量的类型不匹配的database.Try类型解析它以Integer：

cmd.Parameters.Add("@num", SqlDbType.Int).Value = int.Parse(NewID); 

此外，您应该检查您的其他参数类型，并确保它们与SqlDbType's.匹配。对应的类型NVarChar和NText是string。因此，您的其他参数类型（SiteID，ServiceLineID等）应为string。

Answer 3

试试这个：

cmd.Parameters.Add(new SqlParameter() { DbType = DbType.Int32, ParameterName = "@num", Value = Convert.ToInt32(NewID) }); 

我不知道什么是得心脏病在ServiceLineID = HeartAttack.ToString（）;即。一个类型或一个变量。看起来更像一个类型给我。如果我是你，我会将HeartAttackId绑定到dropDown列表中的值。例如：

new ListItem() { Text = "Heart Attack", Value = "1" }; // here 1 is HeartAttackId 

然后retreiving它会像

string ServiceLineID = ((DropDownList)gvMainView.FooterRow.FindControl("ddlServiceLine")).Value;