GridView generated programmatically

[NKaufman]

<asp:GridView ID="Basic" runat="server"
DataKeyNames="QuestionID,isHeading" AutoGenerateColumns="false"
AllowPaging="true" PageSize="100">
<Columns>
<asp:BoundField Visible="false" DataField="QuestionID"
HeaderText="QuestionID"></asp:BoundField>
<asp:BoundField DataField="QuestionDesc"
HeaderText="Question"
ItemStyle-HorizontalAlign="Left"></
asp:BoundField>
<asp:TemplateField HeaderText="Answer">
<ItemTemplate>
<asp:RadioButtonList
RepeatDirection="Horizontal" runat="server"
ID="rdAnswer" SelectedIndex='<%#
SetState(DataBinder.Eval
(Container.DataItem,"Answer"))%>'>
<asp:ListItem Value="0">Yes</
asp:ListItem>
<asp:ListItem Value="1">No</
asp:ListItem>
</asp:RadioButtonList>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>

Hello,

I need to create a gridview programmatically in code that would be
similar to the above code (in design mode).\

Any pointers?

Thanks,

 

[John Timney \(MVP\)]

Someones already done it for you.
http://forums.asp.net/thread/1379019.aspx

Not sure why you wouldn't just use a templated gridview though!

Regards

John Timney (MVP)
http://www.johntimney.com
http://www.johntimney.com/blog

 

[NKaufman]

Hello John,

Following are some of the issues in the example you cited:
(1) All columns of datatable will be displayed. In my case, I need
some columns to be visible and some are not.
(2) Does not handle DataKeys that I need
(3) Does not handle adding a control like the radiobuttonlist that I
need

In a post from the same thread - "why not a basic gridview? .....
since one your example you are not doing additional formatting to the
data other than creating bound columns."

Thanks for you assistance.

 

[John Timney \(MVP\)]

I didn't think the example gave you a perfect solution, only that it would
give you an idea of how to create a datagrid dynamically.

If you use a template against a gridview then you can BIND and EVAL against
any of the datatable values and structure your output as you need it,

Regards

John Timney (MVP)
http://www.johntimney.com
http://www.johntimney.com/blog

 

[Guest]

Hi,

To generate a gridView programmatically, you need to create a GridView
object and assign the properties that you had mentioned.
BoundField objects can be created and added to the gridview object.
Problem comes only when you need to add an ItemTemplate column. I tried a
sample code for the exact same gridView code that you had posted.

//My sample datatable which i am using to bind to the grid view.
DataTable dtSource = new DataTable();
dtSource.Columns.Add("QuestionID");
dtSource.Columns.Add("QuestionDesc");
dtSource.Columns.Add("Answer");
dtSource.Columns.Add("isHeading");

DataRow dr = dtSource.NewRow();
dr[0] = "Q1";
dr[1] = "I like reading books ";
dr[2] = "1";
dr[3] = "true";
dtSource.Rows.Add(dr);

dr = dtSource.NewRow();
dr[0] = "Q2";
dr[1] = "I watch a lot of TV";
dr[2] = "0";
dr[3] = "false";
dtSource.Rows.Add(dr);


//Creating a gridView

GridView gvBasic = new GridView();

gvBasic.DataKeyNames="QuestionID,isHeading".Split(",".ToCharArray());
gvBasic.AutoGenerateColumns = false;
gvBasic.AllowPaging = true;
gvBasic.PageSize = 100;
gvBasic.DataSource = dtSource;

//Your column 1 that is hidden

BoundField objCol1 = new BoundField();
objCol1.Visible= false;
objCol1.DataField = "QuestionID";
objCol1.HeaderText = "QuestionID";
gvBasic.Columns.Add(objCol1);

//Your column 2 that has the questions

BoundField objCol2 = new BoundField();
objCol2.DataField = "QuestionDesc";
objCol2.HeaderText = "Question";
objCol2.ItemStyle.HorizontalAlign = HorizontalAlign.Left;
gvBasic.Columns.Add(objCol2);

//ItemTemplate is an Interface in dotnet and hence,
//Create an ItemTemplate class which implements the interface.

// Your column three which has the radiobuttonList on it

TemplateField objCol3 = new TemplateField();
objCol3.HeaderText = "Answer";
ItemTemplate objTemplate = new ItemTemplate("rdAnswer", dtSource);
objCol3.ItemTemplate = objTemplate;

gvBasic.Columns.Add(objCol3);

gvBasic.DataBind();
Page.Form.Controls.Add(gvBasic);



Code for the ItemTemplate class:


public class ItemTemplate : ITemplate
{

string ControlName = "";
object DataSource = null;

//ControlName: Name of the radio button list.
// DataSource is the datatable to which the gridview is bound to.

public ItemTemplate(string ControlName,object DataSource)
{
this.ControlName = ControlName;
this.DataSource = DataSource;
}


public void InstantiateIn(Control objContainer)
{
RadioButtonList rdAnswer = new RadioButtonList();
rdAnswer.ID = this.ControlName;

//An event is added to traverse every row that is bound to the
//gridview to fetch the answer column.

rdAnswer.DataBinding += new EventHandler(this.OnDataBinding);
ListItem lst1 = new ListItem("Yes","0");
ListItem lst2 = new ListItem("No","1");
rdAnswer.Items.Add(lst1);
rdAnswer.Items.Add(lst2);
objContainer.Controls.Add(rdAnswer);

}

public void OnDataBinding(object sender, EventArgs e)
{
RadioButtonList rdAnswer = (RadioButtonList)sender;
GridViewRow container = (GridViewRow)rdAnswer.NamingContainer;

//Setting the value of the selected index - This is the replacement for the
eval.

rdAnswer.SelectedIndex =
int.Parse(((DataRowView)container.DataItem).Row.ItemArray[2].ToString());

}

}

I guess you shd be all set with this code sample above.

- Parvathy Padmanabhan

 

[NKaufman]

Parvathy,

Excellent. I will try this and let you know.


Thanks,

Hi,

To generate a gridView programmatically, you need to create a GridView
object and assign the properties that you had mentioned.
BoundField objects can be created and added to the gridview object.
Problem comes only when you need to add an ItemTemplate column. I tried a
sample code for the exact same gridView code that you had posted.

//My sample datatable which i am using to bind to the grid view.
DataTable dtSource = new DataTable();
dtSource.Columns.Add("QuestionID");
dtSource.Columns.Add("QuestionDesc");
dtSource.Columns.Add("Answer");
dtSource.Columns.Add("isHeading");

DataRow dr = dtSource.NewRow();
dr[0] = "Q1";
dr[1] = "I like reading books ";
dr[2] = "1";
dr[3] = "true";
dtSource.Rows.Add(dr);

dr = dtSource.NewRow();
dr[0] = "Q2";
dr[1] = "I watch a lot of TV";
dr[2] = "0";
dr[3] = "false";
dtSource.Rows.Add(dr);

//Creating a gridView

GridView gvBasic = new GridView();

gvBasic.DataKeyNames="QuestionID,isHeading".Split(",".ToCharArray());
gvBasic.AutoGenerateColumns = false;
gvBasic.AllowPaging = true;
gvBasic.PageSize = 100;
gvBasic.DataSource = dtSource;

//Your column 1 that is hidden

BoundField objCol1 = new BoundField();
objCol1.Visible= false;
objCol1.DataField = "QuestionID";
objCol1.HeaderText = "QuestionID";
gvBasic.Columns.Add(objCol1);

//Your column 2 that has the questions

BoundField objCol2 = new BoundField();
objCol2.DataField = "QuestionDesc";
objCol2.HeaderText = "Question";
objCol2.ItemStyle.HorizontalAlign = HorizontalAlign.Left;
gvBasic.Columns.Add(objCol2);

//ItemTemplate is an Interface in dotnet and hence,
//Create an ItemTemplate class which implements the interface.

// Your column three which has the radiobuttonList on it

TemplateField objCol3 = new TemplateField();
objCol3.HeaderText = "Answer";
ItemTemplate objTemplate = new ItemTemplate("rdAnswer", dtSource);
objCol3.ItemTemplate = objTemplate;

gvBasic.Columns.Add(objCol3);

gvBasic.DataBind();
Page.Form.Controls.Add(gvBasic);

Code for the ItemTemplate class:

public class ItemTemplate : ITemplate
{

string ControlName = "";
object DataSource = null;

//ControlName: Name of the radio button list.
// DataSource is the datatable to which the gridview is bound to.

public ItemTemplate(string ControlName,object DataSource)
{
this.ControlName = ControlName;
this.DataSource = DataSource;
}

public void InstantiateIn(Control objContainer)
{
RadioButtonList rdAnswer = new RadioButtonList();
rdAnswer.ID = this.ControlName;

//An event is added to traverse every row that is bound to the
//gridview to fetch the answer column.

rdAnswer.DataBinding += new EventHandler(this.OnDataBinding);
ListItem lst1 = new ListItem("Yes","0");
ListItem lst2 = new ListItem("No","1");
rdAnswer.Items.Add(lst1);
rdAnswer.Items.Add(lst2);
objContainer.Controls.Add(rdAnswer);

}

public void OnDataBinding(object sender, EventArgs e)
{
RadioButtonList rdAnswer = (RadioButtonList)sender;
GridViewRow container = (GridViewRow)rdAnswer.NamingContainer;

//Setting the value of the selected index - This is the replacement for the
eval.

rdAnswer.SelectedIndex =
int.Parse(((DataRowView)container.DataItem).Row.ItemArray[2].ToString());

}

}

I guess you shd be all set with this code sample above.

- Parvathy Padmanabhan