自定义的controller
public with sharing class MerchandiseController {
    public List<Merchandise__c> merchandises{get;set;}
    
    public List<SelectOption> merchandisePrices = new List<SelectOption>();
    
    public Merchandise__c merchandise{get;set;}
    
    public Boolean isStatus{get;set;}
    
    public String name{get;set;}
    
    public Decimal quantity{get;set;}
    
    public Decimal price{get;set;}
    
    public MerchandiseController(){
        merchandises = new List<Merchandise__c>();
        refreshData();
    }
    
    public List<SelectOption> getPrice(){
        merchandisePrices.clear();
        merchandisePrices.add(new SelectOption(‘200‘,‘200‘));
        return merchandisePrices;
    }
    
    public void refreshData(){
        isStatus = true;
        String goodsQueryString = ‘SELECT Name,Quantity__c,Price__c from Merchandise__c‘;
        merchandises = Database.query(goodsQueryString);
    }
    
    public void save(){
        upsert merchandises;
    }
    
    public void deleteMerchandises(){
        Id id = ApexPages.currentPage().getParameters().get(‘merchandisesId‘);
        Database.delete(id);
        refreshData();
    }
    
    public void add(){
        if(merchandises == null){
            merchandises = new List<Merchandise__c>();
        }
        Merchandise__c merchandise2 = new Merchandise__c();
        System.debug(‘-----------merchandiseList---------------------‘+merchandises);
        if(merchandises.size()==0){
            merchandises.add(merchandise2);
        }else{
            merchandises.add(0,merchandise2);
        }
    }
    
    public void query(){
        String goodsQueryString = ‘SELECT Name,CreatedBy,LastModifiedBy,Owner,Quantity__c,Price__c from Merchandise__c‘;
        merchandises = Database.query(goodsQueryString);
        
    }
    
}

visual force 的 page页面
<apex:page controller="MerchandiseController" showHeader="false">
    <apex:messages />
    <apex:form >
        <apex:pageBlock title="Merchandises">
            <apex:pageBlockSection title="query merchandises">
                <apex:inputText value="http://www.mamicode.com/{!name}" tabindex="4" label="name" id="name"></apex:inputText>
                <apex:selectList multiselect="false" size="1" value="http://www.mamicode.com/{!price}" label="Price">
                    <apex:selectOptions value="http://www.mamicode.com/{!price}"></apex:selectOptions>
                </apex:selectList>
                <apex:inputText value="http://www.mamicode.com/{!quantity}" tabindex="3" label="Quantity" />
            </apex:pageBlockSection>
            
            <apex:pageBlockTable value="http://www.mamicode.com/{!Merchandises}" var="merchan" id="merchandisResult">
                  <apex:column headervalue="http://www.mamicode.com/name">
                      <apex:inputField value="http://www.mamicode.com/{!merchan.Name}"/>
                  </apex:column>
                  <apex:column headervalue="http://www.mamicode.com/quantity">
                      <apex:inputField value="http://www.mamicode.com/{!merchan.Quantity__c}" />
                  </apex:column>
                  <apex:column headervalue="http://www.mamicode.com/price">
                      <apex:inputField value="http://www.mamicode.com/{!merchan.Price__c}" />
                  </apex:column>
                  <apex:column headervalue="http://www.mamicode.com/delete?">
                      <apex:commandLink value="http://www.mamicode.com/delete" action="{!deleteMerchandises}">
                          <apex:param name="merchandisesId" value="http://www.mamicode.com/{!merchan.Id}"></apex:param>
                      </apex:commandLink>
                  </apex:column>
              </apex:pageBlockTable>
        </apex:pageBlock>
    </apex:form>
</apex:page>