Unknown constructor'.......(ApexPages.StandardController controller)' - salesforce

Question

Unknown constructor'.......(ApexPages.StandardController controller)'
I'm new to Salesforce.
I'm doing a practice problem in which I have to create a Visualforce page to save a contact detail and display that on another VF page.
ContactDetails.vfp :
<apex:page standardController="Contact" extensions="ContactDisplayController">
<apex:form >
<apex:pageBlock title="Add Contact">
<apex:pageBlockSection columns="1">
<apex:inputField value="{! Contact.FirstName }"/>
<apex:inputField value="{! Contact.Lastname }"/>
<apex:inputField value="{! Contact.Phone }" />
<apex:inputField value="{! Contact.Email }" />
<apex:inputField value="{! Contact.Birthdate }" />
</apex:pageBlockSection>
<apex:pageBlockButtons >
<apex:commandButton action="{!saveAndRedirect}" value="Save" />
</apex:pageBlockButtons>
</apex:pageBlock>
</apex:form>
</apex:page>
ContactDisplay.vfp :
<apex:page standardController="Contact" extensions="ContactDisplayController">
<apex:form >
<apex:pageBlock title="Display Contact">
<apex:pageBlockSection columns="1">
<apex:outputText value="{! Contact.FirstName }"/>
<apex:outputText value="{! Contact.Lastname }"/>
<apex:outputText value="{! Contact.Phone }" />
<apex:outputText value="{! Contact.Email }" />
<apex:outputText value="{! Contact.Birthdate }" />
</apex:pageBlockSection>
<apex:pageBlockButtons >
<apex:commandButton action="{!redirectToMyVF}" value="Close" />
</apex:pageBlockButtons>
</apex:pageBlock>
</apex:form>
</apex:page>
ContactDisplayController.apxc :
public class ContactDisplayController {
public Contact con { get; set; }
public ContactDisplayController(ApexPages.StandardController controller) {
}
public PageReference redirectToMyVF() {
PageReference pref = new PageReference('/apex/Page');
pref.setRedirect(true);
return pref;
}
public PageReference saveAndRedirect() {
if(controller.Save() != null) {
//save your contact record
controller.Save();
//retrieve the contact record
con = ( Contact ) controller.getRecord();
System.debug( con );
//pass the contact id as the URL parameter
PageReference redirectPage = '/ContactDisplay?id=' + con.Id;
return redirectPage;
}
return null;
}
}
When I'm trying to save this code I'm getting error :
Unknown constructor 'ContactDisplayController.ContactDisplayController(ApexPages.StandardController controller)'
Please let me know what is wrong with this code.

Answer 1

I don't think your apex class is saving because it should have a few errors in it and therefore your visual force pages won't be able to locate the extensions constructor.
Update your ContactDisplayController Class to the following and make sure it saves without errors first then save you visual force pages and there should be no error
public class ContactDisplayController {
public Contact con { get; set; }
public ApexPages.StandardController controller {get; set;}
public ContactDisplayController(ApexPages.StandardController controller) {
this.controller = controller;
}
public PageReference redirectToMyVF() {
PageReference pref = new PageReference('/apex/Page');
pref.setRedirect(true);
return pref;
}
public PageReference saveAndRedirect() {
if(controller.Save() != null) {
//save your contact record
controller.Save();
//retrieve the contact record
con = ( Contact ) controller.getRecord();
System.debug( con );
//pass the contact id as the URL parameter
PageReference redirectPage = new PageReference('/apex/ContactDisplay?id=' + con.Id);
return redirectPage;
}
return null;
}
}