Filter Contact Based on Account

Requirement: Created a VF Page . Show All Accounts on Drop Down List, When Select Account then related contacts with that Account should be visible in table.

Solution:   Create a VF page and Controller Class as mention below

Page Code

<apex:page controller="ControllerforAccount">

 <apex:form >
     <apex:pageBlock >
         <apex:pageBlockSection columns="1" title="Account">
         
         
         <apex:selectList value="{!selectedAccountId}" size="1">
             <apex:selectOptions value="{!lstSelectOption}"></apex:selectOptions>
          <apex:actionSupport event="onchange" action="{!AllContact}" reRender="contactlistId,outputID"/>
      </apex:selectList> 
      
      <apex:outputLabel value="{!strMessage }" id="outputID"></apex:outputLabel> 
      
                    
         </apex:pageBlockSection>
         
         <apex:pageBlockSection columns="1" id="contactlistId" title="Contacts" >
         
             <apex:pageBlockTable value="{!lstContact}" var="con" rendered="{!isShow}" >
                     <apex:column value="{!con.Name}"/>
                     <apex:column value="{!con.email}"/>
             </apex:pageBlockTable>
         </apex:pageBlockSection> 
     </apex:pageBlock> 
     
 </apex:form>

</apex:page>

Class Code
public class ControllerforAccount {
    
    //  string when you select an accound this variable will fill from account Id
    
    public string selectedAccountId {get;set;}
    public Boolean isshow{get;set;}     
      public string strMessage{get;set;}   
    public List<selectoption> lstSelectOption{get;set;}
    public List<Contact> lstContact {get;set;}
    
    public ControllerforAccount (){
        lstContact  = new List<Contact>();
        isshow =false;
        lstSelectOption = new List<selectoption>();
        ShowAccountRecord();
    }
    
// This method will return list of selectoption and will be bind in VF page in select list
   /* public List<selectoption> getlstAccount(){        
        List<selectoption> lstSelectOption= new List<selectoption>();
        lstSelectOption.add(new selectOption('None','-None-'));        // adding first value in list as None
        for(Account acc : [select Id,Name from Account]){
            lstSelectOption.add(new selectoption(acc.Id,acc.name));
        }
        return lstSelectOption;                
    }*/
    
  public void ShowAccountRecord()
  {
   
      lstSelectOption.add(new selectOption('None','-None-')); 
      
      for(Account acc : [select Id,Name from Account]){
            lstSelectOption.add(new selectoption(acc.Id,acc.name));
        }
      
      
  } 
  
  
//This method is calling from actionsupport action in VF page
    public void AllContact(){
    
         system.debug('selectedAccountId3333******** '+selectedAccountId);
        lstContact  = [select Id,Name,email from Contact where AccountId=:selectedAccountId ]; 
        if(lstContact.size()>0 && lstContact!=null)
        {
          isshow = true;
          strMessage  ='';
        }
        else
        {
         isshow =false;
        strMessage ='No Record found!!!';
        }   
    }

}

snapshot













Thanks
Sumit Shukla
Mob-9711055997
SkypeId: shuklasumit1
sumitshukla.mca@gmail.com