How do I keep dynamically created dropdownlist when event OnSelectedIndex Changed?

[utterberg]

Hi

I'm adding two dropdownlist in my webform by clicking a button. I fill
the first dropdown with some values from my DB and the other one when I
choose from the first dropdown. But since theese dropdownlists are
created by clicking a button they no longer exists on my webform. How
do I keep my dynamically created dropdown when using
OnSelectedIndex Changed? Can anyone help me solve this problem? Or is
there a better way of doing this?

Thanks
..christer

(here's some of my code)
aspx-page:
<asp:Button Runat="server" ID="btnAddGroup " Text="Add Main-/Subgroup"
/>
<asp:PlaceHolde r ID="phGroup" Runat="server" /><asp:PlaceHold er
ID="phSubGroup " Runat="server" />

code behinde (aspx.cs):
private void btnAddGroup_Cli ck(object sender, System.EventArg s e){
CreateDropDown( this.phGroup, "selMainGrp ");
}

private void CreateDropDown( PlaceHolder ph, string id){
DropDownList dd = new DropDownList();
FillMainGrpList Box(ph, dd, id);
}

private void FillMainGrpList Box(PlaceHolder ph, DropDownList dd, string
id){
DropDownList selMainGroup = dd;
string sqlProc = "GetMainGro up";

Data data = new Data();

resultDataSet = data.GetDataSet ByProcName(sqlP roc);

dd.Items.Add("C hoose");

//Fill control
foreach(DataTab le table in resultDataSet.T ables){
foreach(DataRow row in table.Rows){
foreach(DataCol umn col in table.Columns){
//Add maingroup to dropdownlist
selMainGroup.It ems.Add(row[col].ToString());
}
}
}

//Add control
string sAttributes;
sAttributes = "<b>Main Group</b>";
ph.Controls.Add (new LiteralControl( sAttributes));
selMainGroup.ID = id;
selMainGroup.Au toPostBack = true;
selMainGroup.Se lectedIndexChan ged +=new
EventHandler(se lMainGroup_Sele ctedIndexChange d);
ph.Controls.Add (selMainGroup);

//Add Subgroup dropdown
DropDownList ddSub = new DropDownList();
sAttributes = "<b>Sub group</b>";
ddSub.ID = "selSubGrp" ;
ddSub.Items.Add ("Choose");
phSubGroup.Cont rols.Add(new LiteralControl( sAttributes));
phSubGroup.Cont rols.Add(ddSub) ;
}

private void selMainGroup_Se lectedIndexChan ged(object sender,
System.EventArg s e){
string mainGroupValue = this.selMainGrp .SelectedValue;
if(mainGroupVal ue != "Choose"){
//Reset subgroup dropdown
SetDefaultListB oxValue(selSubG rp);

//Add values in subgroup
FillSubGrpListB ox(mainGroupVal ue);
}
}

private void FillSubGrpListB ox(string mainGroupValue) {
string sqlProc = "GetSubGrou p";

string[,] paramArr = {{"@MainGroup", mainGroupValue} };

Data data = new Data();
resultDataSet = data.GetDataSet ByProcName(sqlP roc, paramArr);

foreach(DataTab le table in resultDataSet.T ables){
foreach(DataRow row in table.Rows){
foreach(DataCol umn col in table.Columns){
selSubGrp.Items .Add(row[col].ToString());
}
}
}
}

[Eliyahu Goldin]

Instead of creating the ddls dynamically, put them on the .aspx form in a
normal way and, in run time, control their visibility and databinding
properties.

Eliyahu

<ut*******@gmai l.com> wrote in message
news:11******** *************@g 47g2000cwa.goog legroups.com...

Hi

I'm adding two dropdownlist in my webform by clicking a button. I fill
the first dropdown with some values from my DB and the other one when I
choose from the first dropdown. But since theese dropdownlists are
created by clicking a button they no longer exists on my webform. How
do I keep my dynamically created dropdown when using
OnSelectedIndex Changed? Can anyone help me solve this problem? Or is
there a better way of doing this?

Thanks
.christer

(here's some of my code)
aspx-page:
<asp:Button Runat="server" ID="btnAddGroup " Text="Add Main-/Subgroup"
/>
<asp:PlaceHolde r ID="phGroup" Runat="server" /><asp:PlaceHold er
ID="phSubGroup " Runat="server" />

code behinde (aspx.cs):
private void btnAddGroup_Cli ck(object sender, System.EventArg s e){
CreateDropDown( this.phGroup, "selMainGrp ");
}

private void CreateDropDown( PlaceHolder ph, string id){
DropDownList dd = new DropDownList();
FillMainGrpList Box(ph, dd, id);
}

private void FillMainGrpList Box(PlaceHolder ph, DropDownList dd, string
id){
DropDownList selMainGroup = dd;
string sqlProc = "GetMainGro up";

Data data = new Data();

resultDataSet = data.GetDataSet ByProcName(sqlP roc);

dd.Items.Add("C hoose");

//Fill control
foreach(DataTab le table in resultDataSet.T ables){
foreach(DataRow row in table.Rows){
foreach(DataCol umn col in table.Columns){
//Add maingroup to dropdownlist
selMainGroup.It ems.Add(row[col].ToString());
}
}
}

//Add control
string sAttributes;
sAttributes = "<b>Main Group</b>";
ph.Controls.Add (new LiteralControl( sAttributes));
selMainGroup.ID = id;
selMainGroup.Au toPostBack = true;
selMainGroup.Se lectedIndexChan ged +=new
EventHandler(se lMainGroup_Sele ctedIndexChange d);
ph.Controls.Add (selMainGroup);

//Add Subgroup dropdown
DropDownList ddSub = new DropDownList();
sAttributes = "<b>Sub group</b>";
ddSub.ID = "selSubGrp" ;
ddSub.Items.Add ("Choose");
phSubGroup.Cont rols.Add(new LiteralControl( sAttributes));
phSubGroup.Cont rols.Add(ddSub) ;
}

private void selMainGroup_Se lectedIndexChan ged(object sender,
System.EventArg s e){
string mainGroupValue = this.selMainGrp .SelectedValue;
if(mainGroupVal ue != "Choose"){
//Reset subgroup dropdown
SetDefaultListB oxValue(selSubG rp);

//Add values in subgroup
FillSubGrpListB ox(mainGroupVal ue);
}
}

private void FillSubGrpListB ox(string mainGroupValue) {
string sqlProc = "GetSubGrou p";

string[,] paramArr = {{"@MainGroup", mainGroupValue} };

Data data = new Data();
resultDataSet = data.GetDataSet ByProcName(sqlP roc, paramArr);

foreach(DataTab le table in resultDataSet.T ables){
foreach(DataRow row in table.Rows){
foreach(DataCol umn col in table.Columns){
selSubGrp.Items .Add(row[col].ToString());
}
}
}
}

[utterberg]

What I want to do is click on my "Add"-button and create two dropdowns
- the first I fill with values from my DB. Then I select a value from
the first drop down and fill the other drop down (with another
roundtrip to my DB collecting the new values for the second dropdown).
When that's done I want to click my "Add Selection"-button and add the
selection to my webform (values from both dropdowns). After that I
would like to add another dropdown make my selection and and add it to
my webform, and so on.

When I've made all my selections I would like to press a "Save"-button
and save all the selected values to my DB.

Thus, I do not know in advance how many selections I would like to make
and thats why I wanna create theese controls at run time.

Hope this clarified a bit
..christer

[Eliyahu Goldin]

Do you mean that first "Add" click produces 2 ddls, then another "Add"
produces another 2 ddls and you will have 4 ddls on the form? And 6 ddls
after the third click?

Can't you use the same pair of ddls for every "Add" click?

Eliyahu

<ut*******@gmai l.com> wrote in message
news:11******** **************@ f14g2000cwb.goo glegroups.com.. .

What I want to do is click on my "Add"-button and create two dropdowns
- the first I fill with values from my DB. Then I select a value from
the first drop down and fill the other drop down (with another
roundtrip to my DB collecting the new values for the second dropdown).
When that's done I want to click my "Add Selection"-button and add the
selection to my webform (values from both dropdowns). After that I
would like to add another dropdown make my selection and and add it to
my webform, and so on.

When I've made all my selections I would like to press a "Save"-button
and save all the selected values to my DB.

Thus, I do not know in advance how many selections I would like to make
and thats why I wanna create theese controls at run time.

Hope this clarified a bit
.christer

[utterberg]

Ok. But how do I preserve (and view) the value when I click my "Add
selection"-button?

If I use a <asp:placeholde r ../> for instance and try to place my drop
down values in that place when clicking "Add selection" the page
reloads and selection (value) is gone.

..christer

[Eliyahu Goldin]

If you have 2 static ddls, what stops you from getting their selected values
on server side in the "Add selection" onclick event handler?

Eliyahu

<ut*******@gmai l.com> wrote in message
news:11******** *************@g 49g2000cwa.goog legroups.com...

Ok. But how do I preserve (and view) the value when I click my "Add
selection"-button?

If I use a <asp:placeholde r ../> for instance and try to place my drop
down values in that place when clicking "Add selection" the page
reloads and selection (value) is gone.

.christer

[utterberg]

I am lousy at explaining I think. And my english ain't what it should
be.

I want to preserve/add values in a placeholder when I make my
selection. I can do this with my first dd selection like this.
- Make my selection in my drop down
- Add selection to a placeholder by clicking "btnAddSale s"

aspx:
<label for="selSalesAc count">Sales Account:</label>
<asp:DropDownLi st Runat="server" ID="selSalesAcc ount"
AutoPostBack="T rue" />
<asp:Button Runat="server" ID="btnAddSales " />
<asp:PlaceHolde r Runat="server" ID="phSales" />

code behind:
private void btnAddSales_Cli ck(object sender, EventArgs e){
string val = this.selSalesAc count.SelectedV alue;
TextBox tb = new TextBox();
tb.ID = val;
this.phSales.Co ntrols.Add(tb);
tb.Text = val;
tb.AutoPostBack = true;
}

So now I have my first drop down selection in my placeholder. Now I
want to make another selection from my dropdown and add its value to my
placeholder (making it two values) - but when I choose a new item in
the drop down values preserved in my placeholder is gone.

How do I keep thees selected values when I do another runtrip to the
server?

(this is a simplyfied example of what I want to do, but if I can get
help with this I should be able to sort the rest out myself)

..christer

[Eliyahu Goldin]

A placeholder is not good for you. First of all, choose a class you want to
use to store the selection. It could be an array, ArrayList, SortedList,
DataTable. Secondly, decide on how to make it persistent between the
postbacks. You can put it in a session variable or in the ViewState. Then
finally chose a web control that will render your selection on the page.
Typically it would be a datagrid, a datalist or a repeater. And finally bind
your control to your storage object on every postback.

Eliyahu

<ut*******@gmai l.com> wrote in message
news:11******** **************@ g49g2000cwa.goo glegroups.com.. .

I am lousy at explaining I think. And my english ain't what it should
be.

I want to preserve/add values in a placeholder when I make my
selection. I can do this with my first dd selection like this.
- Make my selection in my drop down
- Add selection to a placeholder by clicking "btnAddSale s"

aspx:
<label for="selSalesAc count">Sales Account:</label>
<asp:DropDownLi st Runat="server" ID="selSalesAcc ount"
AutoPostBack="T rue" />
<asp:Button Runat="server" ID="btnAddSales " />
<asp:PlaceHolde r Runat="server" ID="phSales" />

code behind:
private void btnAddSales_Cli ck(object sender, EventArgs e){
string val = this.selSalesAc count.SelectedV alue;
TextBox tb = new TextBox();
tb.ID = val;
this.phSales.Co ntrols.Add(tb);
tb.Text = val;
tb.AutoPostBack = true;
}

So now I have my first drop down selection in my placeholder. Now I
want to make another selection from my dropdown and add its value to my
placeholder (making it two values) - but when I choose a new item in
the drop down values preserved in my placeholder is gone.

How do I keep thees selected values when I do another runtrip to the
server?

(this is a simplyfied example of what I want to do, but if I can get
help with this I should be able to sort the rest out myself)

.christer

[utterberg]

Ok thanks!
I'll try that.

..christer