Solved

Winform comboBox returns dataRowView

Posted on 2008-10-01
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Last Modified: 2013-12-17
Hi,
I have a dataset bound to comboBox1  with records.
In a certain scenario I have to reload the dataset with some other data if combo2 is selected.

So When combo2 is selected I set the bindings off for the comboBox1 and reload a fresh dataset again.
In the selected change event I try to get the student_id when a name is selected. but it returns system.data.RowView


Its bound for the first time like this
this.combobox1.DataSource = _ds.Tables[0];
this.combobox1.DisplayMember = "Student_name";
this.combobox1.ValueMember = "student_id";
this.combobox1.SelectedIndex = -1;
this.combobox1.SelectedIndexChanged += new System.EventHandlerthis.combobox1_SelectedIndexChanged);
this.combobox1.SelectedIndex = 0;

Now when Combo2 is selected and combobox1 is clicked IN CLICK EVENT OF  of comboBox1

I set the bindings off and bind again in the above way to another dataset as It has to be done on fly (ie when combo2 is selected Combo1 has to load some other data)
 

In the selected change event I try to get the student_ID but it returns data.row.dataviewrow

 
        private void Combobo1_SelectedIndexChanged(object sender, EventArgs e)
        {

         if ( combobox1.SelectedIndex > 0 || combobox1.selectedindex !=-1)    
            {    

                 // this.txtStudentID.Text = combobox1.SelectedItem.ToString();
                MessageBox.Show(combobox1.SelectedItem.ToString());
0
Comment
Question by:dotnet0824
  • 2
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  • +1
8 Comments
 
LVL 8

Expert Comment

by:mac-will
ID: 22618239
Because you are binding to a DataTable each selection is in fact a DataRow.

This is not a problem you can just get what you are looking for like this:



DataRow mRow = (DataRow)combobox1.SelectedItem;
this.txtStudentID.Text = (String)   mRow["student_ID"];


Hope this helps.

MAC
0
 
LVL 26

Expert Comment

by:Anurag Thakur
ID: 22618907
can you please do the following and try
the reason is that before you supply the data source to databind you need to tell that from the data source which column will be the display member and which one will be the value member

this.combobox1.isplayMember = "Student_name";
this.combobox1.ValueMember = "student_id";
this.combobox1.DataSource = _ds.Tables[0];
0
 

Author Comment

by:dotnet0824
ID: 22619073
i have already done that in my posting above.
0
 

Author Comment

by:dotnet0824
ID: 22619107
DataRow mRow = (DataRow)combobox1.SelectedItem;
this.txtStudentID.Text = (String)   mRow["student_ID"];

It says unable to cast DataRowView to DataRow
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LVL 22

Accepted Solution

by:
Snarf0001 earned 300 total points
ID: 22619587
Just use:

this.txtStudentID.Text = combobox1.SelectedValue.ToString();

Since you bound to a datatable, the selectedItem is actually the datarowview from the table.
But since you specified the ValueMember when binding, you can retrieve with .SelectedValue.
0
 
LVL 8

Assisted Solution

by:mac-will
mac-will earned 100 total points
ID: 22621056
Try:

DataRow mRow = ((DataRowView)combobox1.SelectedItem).Row;
this.txtStudentID.Text = (String)   mRow["student_ID"];


0
 
LVL 26

Assisted Solution

by:Anurag Thakur
Anurag Thakur earned 100 total points
ID: 22621670
if you are binding you combobox with DisplayMember and ValueMember properties then to reterieve the student id you can do this
comboBox1.SelectedValue.ToString ()

for fetching the text from the combobox (student name) you can use
comboBox1.SelectedText.ToString()

0
 
LVL 22

Expert Comment

by:Snarf0001
ID: 22623960
ragi007, though agree on the .SelectedValue as i already posted above, .SelectedText is misleading, and returns any text that the user has highlighted.

.Text will return the actual displayed text of the selected item.
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