Question

旧应用程序的部分内容已弃用，我正在尝试重建它。基本上它是一个带月视图的日历。这是我的gridview适配器的一部分：

public View getView(int position, View view, ViewGroup parent) {
    Date date = getItem(position);
    int day = date.getDate();
    int month = date.getMonth();
    int year = date.getYear();
}

和int day = date.getDate(); int month = date.getMonth(); int year = date.getYear(); 不推荐使用。我正在尝试使用Calendar类而不是Date，但无法执行相同操作。我知道，为了检索日，月或年，我可以使用它：

Calendar calendar = Calendar.getInstance();
calendar.get(Calendar.DAY_OF_MONTH);

但我不知道如何转换这一行：

Date date = getItem(position);

与Calendar一起使用。

Answer 1

您可以使用以下代码行：

只需替换此行

Date date = getItem(position);

这一行：

Calendar calendar = Calendar.getInstance();
Date date = calendar.getTime();

以下是您的完整示例：

Calendar calendar = Calendar.getInstance();
Date date = calendar.getTime();
int day =  calendar.get(Calendar.DAY_OF_MONTH);
int month =  calendar.get(Calendar.MONTH);
int year =  calendar.get(Calendar.YEAR);

Answer 2

以下是将Date对象转换为Calendar对象的方法：

Calendar cal = Calendar.getInstance();
cal.setTime(date);

然后（就像你说的那样）你可以这样做：

int day = cal.get(Calendar.DAY_OF_MONTH);
int month = cal.get(Calendar.MONTH)
int year = cal.get(Calendar.YEAR);

Answer 3

首先，您要参考日历。完成后，您可以说Date date = calendar.getTime

public View getView(int position, View view, ViewGroup parent) {
    Calendar calendar = Calendar.getInstance();
    Date date = calendar.getTime();
    int day =  calendar.get(Calendar.DAY_OF_MONTH);
    int month =  calendar.get(Calendar.MONTH)    
    int year =  calendar.get(Calendar.YEAR);
}

Answer 4

寻找可信和/或官方来源的答案。

确定

主要来源：

https://docs.oracle.com/javase/7/docs/api/java/util/Date.html
https://docs.oracle.com/javase/7/docs/api/java/util/Calendar.html

Date。只有一些方法。

所以，

public View getView(int position, View view, ViewGroup parent) {

    Date date = getItem(position);
    long ms = date.getTime();https://docs.oracle.com/javase/7/docs/api/java/util/Date.html#getTime()
    Calendar calendar = Calendar.getInstance();//allowed
    calendar.setTimeInMillis(ms);//allowed https://docs.oracle.com/javase/7/docs/api/java/util/Calendar.html#setTimeInMillis(long)
    //calendar.setTime(date); is also allowed https://docs.oracle.com/javase/7/docs/api/java/util/Calendar.html#setTime(java.util.Date)
    int day =  calendar.get(Calendar.DAY_OF_MONTH);//allowed 
    int month =  calendar.get(Calendar.MONTH);//allowed  
    int year =  calendar.get(Calendar.YEAR);//allowed 
}

Answer 5

以下是从Date转换为Calendar的示例代码。

public View getView(int position, View view, ViewGroup parent) {
    Date date = getItem(position);
    // convert a Date object to a Calendar object
    Calendar calendar = Calendar.getInstance();
    calendar.setTime(date);

    int day =  calendar.get(Calendar.DAY_OF_MONTH);
    int month =  calendar.get(Calendar.MONTH);
    int year =  calendar.get(Calendar.YEAR);
}

GridView用于日历视图

5 个答案: