how to set index of dropdownlist

Question

hello,

in my webpage i boud dropdowdlist by sqldatasource.
now i wan to set the selected item 3 of this dropdwonlist

for example:dropdownlist bound with sqldatasource and dropdownllist has a,b,c,d

now i want to search the item in dropdownlist b then select b on page load

how i do that my code not working

i use this code on page load

dropdownlist.SelectedIndex=convert.toint32(dropdownlost.items.findbytext("b").text);

not working

Mukesh Kumar · Answer

Hi Dharmesh, Try this dropdownlist .SelectedValue = dropdownlist .Items.FindByText("b").Value;

Dharmesh Sharma · Answer

thanks let me try thanks

Krishna Garad · Answer

If it is also correct then it might be problem of blank spaces or this also not working again then try it using SelectedValue. But more work you need to do this Best luck

Dharmesh Sharma · Answer

its not a problem of lower case or upper case cos whatever value in dropdown as i save my database in another page i mean if dropdown has list of country like India,Pakistan then i search like India not india so its shuld me given me any result apart -1 southing wrong

Krishna Garad · Answer

I think so you did not understood my code. I'm not saying that access sqldatasource in your code behind bind your dropdownlist without using sqldatasource. But it will work with sqldatasource also just follow my last post. The major issue here is you getting -1 is the case of listitem. try string _item="b"; string _item1=_item.ToUpper();//or tolower and then pass it to ListItem b = new ListItem(_item1); //this is because of your dropdownlist might contains either uppercase or lowercase and your passing opposite to it. Correct it will work.

Krishna Garad · Answer

Actually no need to change the code your code only can work but check it your dropdownlist contains given listitem in it. This might be a case issue also. You are saying it is returning -1 as index because your dropdownlist dose not contains the given listitem. So please check out whatever listitem you are giving in this line ListItem b = new ListItem("b");//here here i'm giving "b" if it is present then it will return the index of b if it is not present then it will return -1 only. So just follow the case of "b" i.e. uppercase or lowercase.

Dharmesh Sharma · Answer

and this is not a solution how to access sqldatasource in code bhind

Dharmesh Sharma · Answer

but this thing change thousnds of line code in my application so i cant do that find another solution try another

Krishna Garad · Answer

When we are binding our dropdownlist in aspx page it is design time but when we populate our controls with some code in code behind it is runtime. You have to populate you dropdownlist @ runtime in code behind like Page_Load { if(!IsPostBack) { DataSet ds=GetValuesFromDataBase();//This is you method to get dataset from database. DropDownList1.DataSource=ds.Tables[0]; DropDownList1.DataTextField="TextFieldWhichYouWnatToShow"; DropDownList1.DataValueField="ValueFieldWhichYouWantToShow"; DropDownList1.DataBind(); } }

Dharmesh Sharma · Answer

but my dropdownlist bind with sqldatasource on aspx page then how i do like this on page load thanks

Krishna Garad · Answer

as per given code ListItem b = new ListItem("b"); this "b" must be present in your dropdownlist else it will not work. try instead of sqldatasource by manual binding. In this way like if (!IsPostBack) { DropDownList1.Items.Add("a");//here you can bind it manually also DropDownList1.Items.Add("b"); DropDownList1.Items.Add("c"); DropDownList1.Items.Add("d"); ListItem b = new ListItem("b"); int _index =Convert.ToInt32(DropDownList1.Items.IndexOf(b)); DropDownList1.SelectedIndex = _index; }

Dharmesh Sharma · Answer

thanks for reply but its return -1 as my last code the problem is i bound dropdownlist by sqldatasource on aspx page thats wy not find the value in dropdownlist on page load plz help me again thanks

Krishna Garad · Answer

Try like this ListItem b = new ListItem("b"); int _index =Convert.ToInt32(DropDownList1.Items.IndexOf(b)); DropDownList1.SelectedIndex = _index;

how to set index of dropdownlist

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Answers (13)