Visualforce CSV Download

CsvListDownloadPage.page

<apex:page controller="CsvListSearchController" cache="true" contentType="text/csv#filename.csv" language="en-US">
"Name","AccountNumber","Site","NumberOfEmployees"
<apex:repeat value="{!accounts}" var="item">
"{!item.Name}","{!item.AccountNumber}","{!item.Site}","{!item.NumberOfEmployees}"
</apex:repeat>
</apex:page>

CsvListSearchController.cls

public with sharing class CsvListSearchController {
  
    public List<Account> accounts {get; set;}
	
    public CsvListSearchController() {
        this.accounts = new List<Account>();
    }
    
    public void doSearch() {
        this.accounts = [select Id,Name,AccountNumber,Site,NumberOfEmployees from Account limit 200];
    }
    
    public PageReference doClick() {
        return Page.CsvListDownloadPage.setRedirect(false);
    }
}

CsvListSearchPage.page

<apex:page controller="CsvListSearchController" title="CsvListSearchPage" showHeader="true" sidebar="false" id="page">
    <apex:form id="form">
        <apex:pageBlock id="block">
            <apex:pageBlockButtons >
                <apex:commandButton value=" Search!! " title=" Search!! " action="{!doSearch}" reRender="form" />
                <apex:commandButton value=" Download!! " title=" Download!! " action="{!doClick}" rendered="{!accounts.size > 0}" />
            </apex:pageBlockButtons>
            <apex:pageBlockTable value="{!accounts}" var="item">
                <apex:column headerValue="{!$ObjectType.Account.Fields.Name.Label}">
                    <apex:outputText value="{!item.Name}" />
                </apex:column>
                <apex:column headerValue="{!$ObjectType.Account.Fields.AccountNumber.Label}">
                    <apex:outputText value="{!item.AccountNumber}" />
                </apex:column> 
                <apex:column headerValue="{!$ObjectType.Account.Fields.Site.Label}">
                    <apex:outputText value="{!item.Site}" />
                </apex:column> 
                <apex:column headerValue="{!$ObjectType.Account.Fields.NumberOfEmployees.Label}">
                    <apex:outputText value="{!item.NumberOfEmployees}" />
                </apex:column> 
            </apex:pageBlockTable>
        </apex:pageBlock>
    </apex:form>
</apex:page>