How can we create the Dynamic Picklist?

Hi Mohit,

Follow the below code:

Visualforce Page:

<apex:page controller="picklistController" >
<apex:form >
<apex:pageblock >
<apex:pageBlockSection title="Dynamic picklist">
<apex:pageblocksectionItem >
<apex:outputlabel value="City" for="values" />
<apex:selectList value="{!city}" size="1" id="values">
<apex:actionSupport event="onchange" reRender="newvalue" />
<apex:selectOptions value="{!citynames}"/>
</apex:selectList>
</apex:pageblocksectionItem>
<apex:outputpanel id="newvalue">
<apex:outputpanel rendered="{!city == '--Other--'}">
<div style="position:relative;left:75px;">
<apex:outputlabel value="New value" for="newval" />
<apex:inputText value="{!newCity}" id="newval"/>
<apex:commandbutton action="{!saveCity}" value="Add!"/>
</div>
</apex:outputpanel>
</apex:outputpanel>
</apex:pageblocksection>
</apex:pageblock>
</apex:form>
</apex:page>

Apex Controller:

public class picklistController
{
public String city{get; set;}

public String newCity{get; set;}

public List<SelectOption> getcitynames()
{
List<SelectOption> options = new List<SelectOption>();
List<DynamicPicklist__c> citylist = new List<DynamicPicklist__c>();
citylist = [Select Id, PicklistValue__c FROM DynamicPicklist__c ];
options.add(new SelectOption('--None--','--None--'));
for (Integer j=0;j<citylist.size();j++)
{
options.add(new SelectOption(citylist[j].PicklistValue__c,citylist[j].PicklistValue__c));
}
return options;
}

public void saveCity()
{
DynamicPicklist__c newrec = new DynamicPicklist__c(PicklistValue__c=newCity);
insert newrec;
newCity=NULL;
}

}