Question

"Unable to cast object of type 'System.Data.DataRowView' to type 'System.IConvertible'."

Asked by: mathieu_cupryk

private void cbo_Country_SelectedIndexChanged(object sender, EventArgs e)
        {

            // create an array of provinces
            WebSUtil.StateProvince[] stateprovinceArr;

            // create a new object srvCountryCode
            WebSUtil.SrvUtil srvCountryCode = new WebSUtil.SrvUtil();
           
            if (this.cbo_Country.SelectedIndex != -1)
            {
               
                if (cbo_Province.DataSource != null)
                    ((DataTable)cbo_Province.DataSource).Clear();
         
                // Populate the array of provinces

                stateprovinceArr = srvCountryCode.GetProvinceList(Convert.ToDecimal(this.cbo_Country.SelectedValue));


                if (stateprovinceArr != null)
                {
                    DataTable dt = new DataTable();
                    dt.Columns.Add("name");
                    dt.Columns.Add("id");
                    for (int i = 0; i < stateprovinceArr.Length; i++)
                    {
                        DataRow dr = dt.NewRow();
                        dr["name"] = stateprovinceArr[i].Name;
                        dr["id"] = stateprovinceArr[i].Id.ToString();
                        dt.Rows.Add(dr);
                    }
                    this.cbo_Province.DataSource = dt;
                    this.cbo_Province.DisplayMember = "name";
                    this.cbo_Province.ValueMember = "id";

                }
            }



        }


On the first start on the app it crashes on the first start.  There must be a fix for this.

 stateprovinceArr = srvCountryCode.GetProvinceList(Convert.ToDecimal(this.cbo_Country.SelectedValue));

Unable to cast object of type 'System.Data.DataRowView' to type 'System.IConvertible'.

"Unable to cast object of type 'System.Data.DataRowView' to type 'System.IConvertible'."


I have this in the Load Form:


 private void InitializeDropDownListCountry(WebSUtil.SrvUtil srvCountryCode)
        {
           
              WebSUtil.CountryCode[] countryArr = srvCountryCode.GetCountryList();
              DataTable dt = new DataTable();
              dt.Columns.Add("name");
              dt.Columns.Add("id");
              for (int i = 0; i < countryArr.Length; i++)
              {
                DataRow dr = dt.NewRow();
                dr["name"]=countryArr[i].Name;
                dr["id"]=countryArr[i].Id.ToString();
                dt.Rows.Add(dr);
              }
              this.cbo_Country.DataSource=dt;
              this.cbo_Country.DisplayMember="name";
              this.cbo_Country.ValueMember="id";

           
        }

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Asked On
2007-06-26 at 06:12:05ID22658136
Tags

cast

,

object

,

unable

Topic

C# Programming Language

Participating Experts
3
Points
500
Comments
13

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Answers

 

by: gis-jediPosted on 2007-06-26 at 06:29:52ID: 19363408

Try this:

decimal dSelectedId = (decimal)this.cboCounty.SelectedValue;
stateprovinceArr = srvCountryCode.GetProvinceList(dSelectedId);

 

by: TheAvengerPosted on 2007-06-26 at 06:34:35ID: 19363456

Does it crash when the page is first loading? If so, the method cbo_Country_SelectedIndexChanged does not get called at all.

Could you post also the stack trace of the error and the code for the GetProvinceList and the GetCountryList methods?

 

by: mathieu_cuprykPosted on 2007-06-26 at 07:38:20ID: 19364084

YEs it crashes when the first page is loading. I traced it and it goes into the cbo_Country_SelectedIndexChanged.

 

by: TheAvengerPosted on 2007-06-26 at 07:40:39ID: 19364103

OK, on which line exactly does it fail? Could you post the stack trace of the error?

 

by: mathieu_cuprykPosted on 2007-06-26 at 07:42:35ID: 19364129

Unable to cast object of type 'System.Data.DataRowView' to type 'System.IConvertible'.

{"Unable to cast object of type 'System.Data.DataRowView' to type 'System.IConvertible'."}

 

by: TheAvengerPosted on 2007-06-26 at 07:44:38ID: 19364151

That's the exception message. The stack trace is a list of methods that were called and show exactly in which method on which line the error occured. You could see it under the exception message (if you use standard errors) or you can get it from the exception's StackTrace property

 

by: gis-jediPosted on 2007-06-26 at 07:59:41ID: 19364326

He said in his original message that it failed here:

stateprovinceArr = srvCountryCode.GetProvinceList(Convert.ToDecimal(this.cbo_Country.SelectedValue));

Did you try what I said?

 

by: TheAvengerPosted on 2007-06-26 at 08:05:57ID: 19364402

I know now what the problem is (thanks qis-jedi).

this.cbo_Country.SelectedValue is a DataRowView. You need to do the following:

stateprovinceArr = srvCountryCode.GetProvinceList(Convert.ToDecimal(((DataRowView)this.cbo_Country.SelectedValue).Row["id"]));

 

by: mathieu_cuprykPosted on 2007-06-26 at 08:32:07ID: 19364748

It fails on France:
-            cbo_Province.DataSource      {}      object {System.Data.DataTable}
+            base      {}      System.ComponentModel.MarshalByValueComponent {System.Data.DataTable}
            CaseSensitive      false      bool
+            ChildRelations      {System.Data.DataRelationCollection.DataTableRelationCollection}      System.Data.DataRelationCollection {System.Data.DataRelationCollection.DataTableRelationCollection}
+            Columns      {System.Data.DataColumnCollection}      System.Data.DataColumnCollection
+            Constraints      {System.Data.ConstraintCollection}      System.Data.ConstraintCollection
+            DataSet      null      System.Data.DataSet
+            DefaultView      {System.Data.DataView}      System.Data.DataView
            DisplayExpression      ""      string
+            ExtendedProperties      Count = 0      System.Data.PropertyCollection
            HasErrors      false      bool
            IsInitialized      true      bool
+            Locale      {en-US}      System.Globalization.CultureInfo
            MinimumCapacity      50      int
            Namespace      ""      string
+            ParentRelations      {System.Data.DataRelationCollection.DataTableRelationCollection}      System.Data.DataRelationCollection {System.Data.DataRelationCollection.DataTableRelationCollection}
            Prefix      ""      string
            PrimaryKey      {Dimensions:[0]}      System.Data.DataColumn[]
            RemotingFormat      Xml      System.Data.SerializationFormat
+            Rows      {System.Data.DataRowCollection}      System.Data.DataRowCollection
            Site      null      System.ComponentModel.ISite
            TableName      ""      string
+            Static members            
+            Non-Public members            

{"Unable to cast object of type 'System.String' to type 'System.Data.DataRowView'."}

 

by: mathieu_cuprykPosted on 2007-06-26 at 08:33:28ID: 19364769

and US.
It fails the next time I try to change the value, if I trace it.

 

by: mathieu_cuprykPosted on 2007-06-26 at 08:38:19ID: 19364839

I think it has something to do with initialization. I can't figure this out.

 

by: steelheart38Posted on 2007-06-26 at 09:14:33ID: 19365260

       // I would suggest doing it this way
            this.cbo_Country.DisplayMember = "name";
            this.cbo_Country.ValueMember = "id";
            this.cbo_Country.DataSource = dt;

        // note that the displayMember and ValueMember is set before DataSource is set
        // this will result int this.comboBox1.SelectedValue becoming of type string (or depending on what underlying type you assing to row["id"]
        // your stateprovinceArr code should now look like (if not exactly) below
            stateprovinceArr =
                srvCountryCode.GetProvinceList(
                    Convert.ToDecimal(this.cbo_Country.SelectedValue));

 

by: mathieu_cuprykPosted on 2007-06-26 at 10:52:06ID: 19366131

Very good job guys!!!

20120131-EE-VQP-002

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