How to hide Dropdownlists?

Question

Hi In my application there 10 dropdownlists are there in 's & 's depending up on the user selected value from the first dropdownlist(one selection will display one ddl).The data in dropdown is added as DATATABLE using C# Asp.Net...... plz tell the code for it. thanks.

Gohil Jayendrasinh · Answer

Hi I think you have not requirement of hide the drop down 1) Create One Dropdown. 2) Put Placeholder on your .aspx page. 3) On selected Event identify how many dropdown do you want? 4) Create Dynamic Dropdown control and add control to Placeholder.

Gunti Dilip · Answer

I got it thnaks guys.

Senthilkumar · Answer

Hi Step 1: Design All the drop down and do not use the different drop down for different purpose. Calculate the maximum number of drop downs required. You can assign the different data source to the same control... Step 2: Set the visible false to the unwanted drop down initially. Set the data source to the first control and try to use the DataTextField and DataValueField...Because the DataTextField should be used to display text and DataValueField is unique value. Step3: Write the indexchanged event to the dropdown and enable the autopostback=true property. Then write the logics to get the value from the selected dropdown and populate the value to the subsequent dropdown and make that drop down as visible. I would suggest you to use the update panel from the Ajax. Because it will be fast to render and avoid the post back. Otherwise it will take too much time to load and render every time when you select the drop down control.

Pramod Kumar Nandagiri · Answer

yea. but i thought not only hiding dropdown's but also simultanious binding of respective drop down lists with previous ddl selected value such case server side coding is necessary other wise client side coding can be done

Jignesh Trivedi · Answer

hi Agree with pramod. Only one thing wat add Hide show logic  you can also write using JAVA SCRIPT or JQuery it reduce ur server call. hence increace performance.

Pramod Kumar Nandagiri · Answer

Hi  i didn't observe u r hide princeple here iam explaining it First put all dropdown's visiblity false in page_load event except first drop down then set every drop down visibility true in it's previous drop down selected index changed event like below protected void Page_Load(object sender EventArgs e) { if (!IsPostBack) { DropDownList2.Visible = false; ... ... DropDownList10.Visible = false; } } protected void DropDownList1_SelectedIndexChanged(object sender EventArgs e) { DropDownList2.Visible = true; } protected void DropDownList2_SelectedIndexChanged(object sender EventArgs e) { DropDownList3.Visible = true; } protected void DropDownList3_SelectedIndexChanged(object sender EventArgs e) { DropDownList4.Visible = true; }

Pramod Kumar Nandagiri · Answer

Bind the first drop down in page_load event and bind each other drop down in pervious drop down's onselectedindexchanged event like below In each dropdown's selected index changed event the other drop down bind will occur protected void Page_Load(object sender EventArgs e) { if (!IsPostBack) { DropDownList1.DataSource = datatable; DropDownList1.DataBind(); } } protected void DropDownList1_SelectedIndexChanged(object sender EventArgs e) { //write sql query based on first drop down selected text or selected value string strsql = Select * from table where coulumn= + DropDownList1.SelectedItem.Text; ... ... //code to fill datatable2 ... DropDownList2.DataSource = datatable2; DropDownList2.DataBind(); } protected void DropDownList2_SelectedIndexChanged(object sender EventArgs e) { string strsql = Select * from table where coulumn= + DropDownList2.SelectedItem.Text; ... ... //code to fill datatable3 ... DropDownList3.DataSource = datatable3; DropDownList3.DataBind(); } protected void DropDownList3_SelectedIndexChanged(object sender EventArgs e) { string strsql = Select * from table where coulumn= + DropDownList3.SelectedItem.Text; ... ... //code to fill datatable4 ... DropDownList4.DataSource = datatable; DropDownList4.DataBind(); } I hope you would understand...