This is what I wanted as on UI.

This is my formatter

static String formatMonthToYear(DateTime? date, BuildContext context){
    if (date == null) return "Invalid date";
    var formatter = DateFormat('yMMMM');
    return formatter.format(date);
  }

I want to put date time here in Text.

Text(DateTimeUtil.formatMonthToYear(invoiceTotal.data!.map((e) => e.dueDate) as DateTime, context),
                      style: const TextStyle(
                          fontWeight: FontWeight.bold,
                          fontFamily: 'quicksand_bold',
                          fontSize: 20
                      ),
                    ),

This is the data i'm passing.

dueDate: json["due_date"] == null? null: DateTime.parse(json["due_date"]),

CodePudding user response：

First of all

 static String formatMonthToYear(DateTime? date){ // <=== change here because you do not need to pass context.
        if (date == null) return "Invalid date";
        var formatter = DateFormat('yMMMM');
        return formatter.format(date);
      }

Then try this...

Text(DateTimeUtil.formatMonthToYear(invoiceTotal.data!.map((e) => DateTime.parse(e.dueDate).toString())),// <=== change here 
                      style: const TextStyle(
                          fontWeight: FontWeight.bold,
                          fontFamily: 'quicksand_bold',
                          fontSize: 20
                      ),
                    ),

because when you are passing Date it is in String so rather then assign as DateTime above is better way to do.