How to override and add visualforce page to the button

Question

I already have in my Visualforce page the following:

<apex:page Controller="CandidateController" >

if I add to this: <apex:page standardController="Candidate__c" Controller="CandidateController" getting this error:

Error Error: A custom and standard controller cannot be referenced in the same page.

How do you wire-up the custom Visualforce page to a default button? what I meant is that if you click on the New or New Candidate as shown in the below screen shots it gives me the standard page layout but instead I want to override to the Visualforce page.

Answer 1

There are two steps to override standard action with custom visualforce page.

1. Create a new visualforce page by defining that object as standard controller as shown below

   <apex:page standardcontroller="Candidate__c"></apex:page>

2. Override the standard new action of that object.

Go to detail page of your object and look for button related list as shown below

click on edit against New Label and on the next screen visualforce which you have created in step 1.