如何将当前月份显示为文本并传递值?

我考虑了眼霜的第一个答案,并提出了以下逻辑

DateTime d = System.now();
for(Integer i = 1; i < 13; ++i){
            String label = d.format('MMMM yyyy');
this.monthList.add(new SelectOption(String.valueOf(i), label));
            d = d.addMonths(-1);
        } 

Integer month_Sel = date.today().month()-(Integer.valueOf(monthSelection)-1);
        Integer year_Sel = date.today().year();
        if(month_Sel <= 0){
            month_Sel = 12+month_Sel;
            year_Sel = year_Sel-1;
        }
Date thisMonthDate = date.newInstance(year_Sel, month_Sel, 1);

输出如下

September 2017
August 2017
.
.
October 2016

现在,我的查询将获取year\u sel和month\u sel的值,并返回年份和月份选择。

谢谢你的逻辑。

这个 SelectOption value 和 label 参数。所以你们可以在一个月内有更人性化的标签,但仍然可以把它作为一个数字传递给Apex。

这是一个相当复杂的演示。看见 edit history 对于早期版本(&P);解释一些技巧。

<apex:page controller="StackOverflow45934022">

<apex:form >
    <fieldset>
        <legend>Single dropdown</legend>
        <apex:selectList value="{!monthAndYear}" multiselect="false" size="1">
            <apex:selectOptions value="{!monthAndYearOptions}" />
            <apex:actionSupport action="{!submitSingle}" event="onchange" reRender="results" />
        </apex:selectList>
    </fieldset>

    <fieldset>
        <legend>Two dropdowns</legend>
        <apex:selectList value="{!year}" multiselect="false" size="1">
            <apex:selectOptions value="{!yearOptions}" />
        </apex:selectList>
        <apex:selectList value="{!month}" multiselect="false" size="1">
            <apex:selectOption itemValue="1" itemLabel="January"/> <!-- You can use itemLabel="{!$Label.PD_General_Month_Jan}" -->
            <apex:selectOption itemValue="2" itemLabel="February"/>
            <apex:selectOption itemValue="3" itemLabel="March"/>
            <apex:selectOption itemValue="11" itemLabel="November"/>
            <apex:selectOption itemValue="12" itemLabel="December"/>
        </apex:selectList>
        <apex:commandButton value="Submit" action="{!submitMultiple}" reRender="results" />
    </fieldset>
</apex:form>

<hr/>

<apex:outputPanel id="results">
    Month (as integer) : {!m}<br/>
    Year : {!y}
</apex:outputPanel>
</apex:page>

public with sharing class StackOverflow45934022{

    public Integer m {get;private set;}
    public Integer y {get; private set;}

    public StackOverflow45934022(){
        m = System.today().month();
        y = System.today().year();
    }

    // Single dropdown version start
    public String monthAndYear {get;set;}

    public List<SelectOption> getMonthAndYearOptions(){
        List<SelectOption> ret = new List<SelectOption>();
        Date thisMonth = System.today().toStartOfMonth(), januaryLastYear = Date.newInstance(System.today().year() -1, 1, 1);
        DateTime d = DateTime.newInstance(thisMonth, Time.newInstance(0,0,0,0));
        while(d >= januaryLastYear){
            ret.add(new SelectOption(d.format('MM-YYYY'), d.format('MMMM YYYY'))); // you will use your map with month names to build labels
            d = d.addMonths(-1);
        }
        return ret;
    }

    public void submitSingle(){
        if(String.isNotBlank(monthAndYear) && monthAndYear.contains('-')){
            List<String> temp = monthAndYear.split('-');
            m = Integer.valueOf(temp[0]);
            y = Integer.valueOf(temp[1]);
        }
    }
    // Single dropdown version end


    public String year {get;set;}
    public String month {get; set;}

    public List<SelectOption> getYearOptions(){
        Date today = System.today();
        String y0 = String.valueOf(today.year()), y1 = String.valueOf(today.year() -1);
        return new List<SelectOption>{
            new SelectOption(y0, y0),
            new SelectOption(y1, y1)
        };
    }

    public void submitMultiple(){
        m = Integer.valueOf(month);
        y = Integer.valueOf(year);
    }
}