"John Blair" <john_bl***@hotmail.com> ha scritto nel messaggio
news:bzwog.81853$rC1.39577@newsfe4-gui.ntli.net...
> Hi,
>
> I am adding a row of dropdownlist controls to my datagrid in a custom
> control
> - i am adding a selectedindexchanged event to each of these ddls with
> autopostback set to true. The postback happens but the
> selectedindexchanged
> event does not fire? I am creating the ddls in the overriden
> CreateChildControls method of the control. Note: the ddl viewstate is
> saved and restored ok in this control but the selectedindexchanged  event
> handler just not trigger.
>
> Any idea how to wire this event up such that it fires as expected?
>
> thanks a lot!
>

"Alessandro Zifiglio" <AlessandroZifiglio @ -h-o-t-m-a-i-l-c-o-m> ha scritto
nel messaggio news:O%23ET0esmGHA.3600@TK2MSFTNGP02.phx.gbl...
> hi John, you need to find your dropdownlist in your datagrids,
> onItemCreated or onItemDataBound method and once you find the control in
> question(your dropdownlist in this case) hookup its event there.
> Regards,
> Alessandro Zifiglio
> "John Blair" <john_bl***@hotmail.com> ha scritto nel messaggio
> news:bzwog.81853$rC1.39577@newsfe4-gui.ntli.net...
>> Hi,
>>
>> I am adding a row of dropdownlist controls to my datagrid in a custom
>> control
>> - i am adding a selectedindexchanged event to each of these ddls with
>> autopostback set to true. The postback happens but the
>> selectedindexchanged
>> event does not fire? I am creating the ddls in the overriden
>> CreateChildControls method of the control. Note: the ddl viewstate is
>> saved and restored ok in this control but the selectedindexchanged  event
>> handler just not trigger.
>>
>> Any idea how to wire this event up such that it fires as expected?
>>
>> thanks a lot!
>>
>
>

"John Blair" <john_bl***@hotmail.com> ha scritto nel messaggio
news:YSyog.70355$uP.39938@newsfe2-gui.ntli.net...
> Hi Alessandro ,
>
> Thanks for replaying ...it is a custom contol derived from datagrid ....
> here's the relevant snippet!
>
>
> protected override void CreateControlHierarchy(bool useDataSource)
> .
> .
> .
>      CreateFilterControlHierarchy(useDataSource));
>
> .
> .
> .
>
>    protected void  CreateFilterControlHierarchy(bool useDataSource){
>
>      //Data Grid table is the first control in the collection.
>      Table dataGridTable = Controls[0] as Table;
>      Page.Trace.Write("DataGrid:Begin CreateFilterControlHierarchy");
>
>
>      //Get the table header row.
>      DataGridItem dataGridItem = dataGridTable.Controls[0] as
> DataGridItem;
>
>      //Add a ddl to each column in the header.
>      //Use style sheet "td.DataGridHeaderCell select" to make
>      //sure each ddl is on a new line with spacing between the column
>      //header text or sort link.
>      int i =0;
>      foreach (Control c in dataGridItem.Controls){
>        DropDownList ddl = new DropDownList();
>        //Begin tracking viewstate.
>        c.Controls.AddAt(c.Controls.Count,ddl);
>
>        //Populate the ddls.
>        //Note: If not using the datasource rely on viewstate to restore
>        //ddl filter content.
>        string columnName =
> DataSourceDataSet.Tables[0].Columns[i].ColumnName;
>        ddl.ID=columnName;
>
>        ddl.AutoPostBack=true;
>
>       //THIS IS IGNORED!!!!!
>        ddl.SelectedIndexChanged += new EventHandler(
>          this.DataGridDropDownList_SelectedIndexChanged);
>
>        if (useDataSource){
>          PopulateDDL(
>            ddl,
>            DataSourceDataSet.Tables[0],
>            columnName);
>
>          //Initialise view state.
>          ViewState[columnName] = ddl.Items[0].Text;
>        }
>        else{
>          //Use existing viewstate.
>        }
>
>      }
>      Page.Trace.Write("DataGrid:End CreateFilterControlHierarchy");
>
>
>    }
> .
> .
>
>
>

"Alessandro Zifiglio" <AlessandroZifiglio @ -h-o-t-m-a-i-l-c-o-m> wrote in
message news:edd61o1mGHA.2252@TK2MSFTNGP04.phx.gbl...
> hi John, seems like working code. I have tried to test your code and it
> seems to works well, with your selectedIndexChanged event triggering as
> expected :
>
> public class MyCustomDataGrid : DataGrid
>    {
>        protected override void CreateControlHierarchy(bool useDataSource)
>        {
>            base.CreateControlHierarchy(useDataSource);
>            Table dataGridTable = Controls[0] as Table;
>            //Get the table header row.
>            DataGridItem dataGridItem = dataGridTable.Controls[0] as
> DataGridItem;
>
>            //Add a ddl to each column in the header.
>            //Use style sheet "td.DataGridHeaderCell select" to make
>            //sure each ddl is on a new line with spacing between the
> column
>            //header text or sort link.
>            foreach (Control c in dataGridItem.Controls)
>            {
>                System.Web.UI.WebControls.DropDownList DropDownList1 = new
> DropDownList();
>                c.Controls.AddAt(c.Controls.Count, DropDownList1);
>                DropDownList1.AutoPostBack = true;
>                DropDownList1.SelectedIndexChanged += new
> System.EventHandler(this.DropDownList1_SelectedIndexChanged);
>                if (useDataSource)
>                {
>                    DropDownList1.Items.Add(new ListItem("1", "a"));
>                    DropDownList1.Items.Add(new ListItem("2", "b"));
>                    DropDownList1.Items.Add(new ListItem("3", "c"));
>                }
>            }
>
>
>        }
>        private void DropDownList1_SelectedIndexChanged(object sender,
> System.EventArgs e)
>        {
>            Context.Response.Write("Raised dropdownlist
> selectedindexchanged");
>        }
>    }
>
>
> Page to test the custom DataGrid Control :
> ----------------------------------------
>
>
> protected void Page_Load(object sender, EventArgs e)
>    {
>        if (!this.Page.IsPostBack)
>        {
>            this.MyCustomDataGrid1.DataSource = CreateDataSource();
>            this.MyCustomDataGrid1.DataBind();
>        }
>    }
>    ICollection CreateDataSource()
>    {
>        DataTable dt = new DataTable();
>        DataRow dr;
>
>        dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
>        dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
>        dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
>
>        for (int i = 0; i < 9; i++)
>        {
>            dr = dt.NewRow();
>
>            dr[0] = i;
>            dr[1] = "Item " + i.ToString();
>            dr[2] = 1.23 * (i + 1);
>
>            dt.Rows.Add(dr);
>        }
>
>        DataView dv = new DataView(dt);
>        return dv;
>    }
>
> "John Blair" <john_bl***@hotmail.com> ha scritto nel messaggio
> news:YSyog.70355$uP.39938@newsfe2-gui.ntli.net...
>> Hi Alessandro ,
>>
>> Thanks for replaying ...it is a custom contol derived from datagrid ....
>> here's the relevant snippet!
>>
>>
>> protected override void CreateControlHierarchy(bool useDataSource)
>> .
>> .
>> .
>>      CreateFilterControlHierarchy(useDataSource));
>>
>> .
>> .
>> .
>>
>>    protected void  CreateFilterControlHierarchy(bool useDataSource){
>>
>>      //Data Grid table is the first control in the collection.
>>      Table dataGridTable = Controls[0] as Table;
>>      Page.Trace.Write("DataGrid:Begin CreateFilterControlHierarchy");
>>
>>
>>      //Get the table header row.
>>      DataGridItem dataGridItem = dataGridTable.Controls[0] as
>> DataGridItem;
>>
>>      //Add a ddl to each column in the header.
>>      //Use style sheet "td.DataGridHeaderCell select" to make
>>      //sure each ddl is on a new line with spacing between the column
>>      //header text or sort link.
>>      int i =0;
>>      foreach (Control c in dataGridItem.Controls){
>>        DropDownList ddl = new DropDownList();
>>        //Begin tracking viewstate.
>>        c.Controls.AddAt(c.Controls.Count,ddl);
>>
>>        //Populate the ddls.
>>        //Note: If not using the datasource rely on viewstate to restore
>>        //ddl filter content.
>>        string columnName =
>> DataSourceDataSet.Tables[0].Columns[i].ColumnName;
>>        ddl.ID=columnName;
>>
>>        ddl.AutoPostBack=true;
>>
>>       //THIS IS IGNORED!!!!!
>>        ddl.SelectedIndexChanged += new EventHandler(
>>          this.DataGridDropDownList_SelectedIndexChanged);
>>
>>        if (useDataSource){
>>          PopulateDDL(
>>            ddl,
>>            DataSourceDataSet.Tables[0],
>>            columnName);
>>
>>          //Initialise view state.
>>          ViewState[columnName] = ddl.Items[0].Text;
>>        }
>>        else{
>>          //Use existing viewstate.
>>        }
>>
>>      }
>>      Page.Trace.Write("DataGrid:End CreateFilterControlHierarchy");
>>
>>
>>    }
>> .
>> .
>>
>>
>>
>
>

"John Blair" <john_bl***@hotmail.com> ha scritto nel messaggio
news:YISog.82968$rC1.24036@newsfe4-gui.ntli.net...
> Hi Alessandro,
>
> You're a genius! Thanks a lot!
>
> Your sample did the trick - i spent ages trying to work out why your
> sample worked and my "working code" did not as they
> essentially do the same thing.
>
> Finally found it (and it really pissed me off!).
> The only difference between your code and mine was how we loaded the
> dropdownlist controls.
> You populate both the text and the value with non-null data, I populated
> all the values with a null string.
> When i changed the value string.Empty to be the same as the text - my code
> started receiving the events.
> I can't believe it - i am only interested in the text value and not the
> value so didn't see any point in populating it.
> I did some research and it turns out that the event does not fire on
> change of index - it only
> fires if the index is changed and the option VALUE for the new index has
> also changed.
>
> Thank you very much for your help! .... John.
>
>
>
> Your code: DropDownList1.Items.Add(new ListItem("1", "a"));
> If you replace "a","b","c" with string.Emtpy you will notice the events
> stop arriving!
> Because the option value never changes from its initial setting
> string.Empty!.
>
> My Code: ddl.Items.Add( new ListItem(dataRowView[columnName].ToString(),
> string.Empty));
>
>
>
>
> "Alessandro Zifiglio" <AlessandroZifiglio @ -h-o-t-m-a-i-l-c-o-m> wrote in
> message news:edd61o1mGHA.2252@TK2MSFTNGP04.phx.gbl...
>> hi John, seems like working code. I have tried to test your code and it
>> seems to works well, with your selectedIndexChanged event triggering as
>> expected :
>>
>> public class MyCustomDataGrid : DataGrid
>>    {
>>        protected override void CreateControlHierarchy(bool useDataSource)
>>        {
>>            base.CreateControlHierarchy(useDataSource);
>>            Table dataGridTable = Controls[0] as Table;
>>            //Get the table header row.
>>            DataGridItem dataGridItem = dataGridTable.Controls[0] as
>> DataGridItem;
>>
>>            //Add a ddl to each column in the header.
>>            //Use style sheet "td.DataGridHeaderCell select" to make
>>            //sure each ddl is on a new line with spacing between the
>> column
>>            //header text or sort link.
>>            foreach (Control c in dataGridItem.Controls)
>>            {
>>                System.Web.UI.WebControls.DropDownList DropDownList1 = new
>> DropDownList();
>>                c.Controls.AddAt(c.Controls.Count, DropDownList1);
>>                DropDownList1.AutoPostBack = true;
>>                DropDownList1.SelectedIndexChanged += new
>> System.EventHandler(this.DropDownList1_SelectedIndexChanged);
>>                if (useDataSource)
>>                {
>>                    DropDownList1.Items.Add(new ListItem("1", "a"));
>>                    DropDownList1.Items.Add(new ListItem("2", "b"));
>>                    DropDownList1.Items.Add(new ListItem("3", "c"));
>>                }
>>            }
>>
>>
>>        }
>>        private void DropDownList1_SelectedIndexChanged(object sender,
>> System.EventArgs e)
>>        {
>>            Context.Response.Write("Raised dropdownlist
>> selectedindexchanged");
>>        }
>>    }
>>
>>
>> Page to test the custom DataGrid Control :
>> ----------------------------------------
>>
>>
>> protected void Page_Load(object sender, EventArgs e)
>>    {
>>        if (!this.Page.IsPostBack)
>>        {
>>            this.MyCustomDataGrid1.DataSource = CreateDataSource();
>>            this.MyCustomDataGrid1.DataBind();
>>        }
>>    }
>>    ICollection CreateDataSource()
>>    {
>>        DataTable dt = new DataTable();
>>        DataRow dr;
>>
>>        dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
>>        dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
>>        dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
>>
>>        for (int i = 0; i < 9; i++)
>>        {
>>            dr = dt.NewRow();
>>
>>            dr[0] = i;
>>            dr[1] = "Item " + i.ToString();
>>            dr[2] = 1.23 * (i + 1);
>>
>>            dt.Rows.Add(dr);
>>        }
>>
>>        DataView dv = new DataView(dt);
>>        return dv;
>>    }
>>
>> "John Blair" <john_bl***@hotmail.com> ha scritto nel messaggio
>> news:YSyog.70355$uP.39938@newsfe2-gui.ntli.net...
>>> Hi Alessandro ,
>>>
>>> Thanks for replaying ...it is a custom contol derived from datagrid ....
>>> here's the relevant snippet!
>>>
>>>
>>> protected override void CreateControlHierarchy(bool useDataSource)
>>> .
>>> .
>>> .
>>>      CreateFilterControlHierarchy(useDataSource));
>>>
>>> .
>>> .
>>> .
>>>
>>>    protected void  CreateFilterControlHierarchy(bool useDataSource){
>>>
>>>      //Data Grid table is the first control in the collection.
>>>      Table dataGridTable = Controls[0] as Table;
>>>      Page.Trace.Write("DataGrid:Begin CreateFilterControlHierarchy");
>>>
>>>
>>>      //Get the table header row.
>>>      DataGridItem dataGridItem = dataGridTable.Controls[0] as
>>> DataGridItem;
>>>
>>>      //Add a ddl to each column in the header.
>>>      //Use style sheet "td.DataGridHeaderCell select" to make
>>>      //sure each ddl is on a new line with spacing between the column
>>>      //header text or sort link.
>>>      int i =0;
>>>      foreach (Control c in dataGridItem.Controls){
>>>        DropDownList ddl = new DropDownList();
>>>        //Begin tracking viewstate.
>>>        c.Controls.AddAt(c.Controls.Count,ddl);
>>>
>>>        //Populate the ddls.
>>>        //Note: If not using the datasource rely on viewstate to restore
>>>        //ddl filter content.
>>>        string columnName =
>>> DataSourceDataSet.Tables[0].Columns[i].ColumnName;
>>>        ddl.ID=columnName;
>>>
>>>        ddl.AutoPostBack=true;
>>>
>>>       //THIS IS IGNORED!!!!!
>>>        ddl.SelectedIndexChanged += new EventHandler(
>>>          this.DataGridDropDownList_SelectedIndexChanged);
>>>
>>>        if (useDataSource){
>>>          PopulateDDL(
>>>            ddl,
>>>            DataSourceDataSet.Tables[0],
>>>            columnName);
>>>
>>>          //Initialise view state.
>>>          ViewState[columnName] = ddl.Items[0].Text;
>>>        }
>>>        else{
>>>          //Use existing viewstate.
>>>        }
>>>
>>>      }
>>>      Page.Trace.Write("DataGrid:End CreateFilterControlHierarchy");
>>>
>>>
>>>    }
>>> .
>>> .
>>>
>>>
>>>
>>
>>
>
>