Android / Java - 如何使用datepicker更新mapfragment？

Question

应用中的地图使用叠加，部分取决于数据的日期，默认情况下，我希望它显示当前日期的数据，用户可以点按日期以显示日期选择器。到目前为止这是有效的，但由于我设法让日期选择器工作的唯一方法是在static class内创建MainActivity，它无法访问外部类中的任何内容，因此可以＆ ＃39; t使用getMapAsync。一旦用户选择了日期，该应用如何使用OnMapReady？

public class MainActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener, OnMapReadyCallback, OnDateSetListener{



        static Calendar calendar = Calendar.getInstance();
        static SimpleDateFormat sysFormat = new SimpleDateFormat("yyyy-MM-dd", Locale.US);
        static String sysDate = sysFormat.format(calendar.getTime());
        static DateFormat userFormat = (DateFormat.getDateInstance());
        static String userDate = userFormat.format(calendar.getTime());

        ...

        @Override
        protected void onCreate(Bundle savedInstanceState) {
             TextView displayDate = (TextView)findViewById(R.id.displayDate);
             displayDate.setText(userDate);
             displayDate.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                  DialogFragment datePicker = new DatePickerFragment();
                  datePicker.show(getSupportFragmentManager(), "datePicker");
             }
          });
         }

        ...

        @Override
        public void onMapReady(GoogleMap googleMap) {
        //sysDate used in overlay link
        }

        @Override
        public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
        //if possible I would like this to be called rather than the one below
        }


        public static class DatePickerFragment extends DialogFragment implements OnDateSetListener{

             @Override
             public Dialog onCreateDialog(Bundle savedInstanceState) {
                 // Use the current date as the default date in the picker
                 final Calendar c = Calendar.getInstance();
                 int year = c.get(Calendar.YEAR);
                 int month = c.get(Calendar.MONTH);
                 int day = c.get(Calendar.DAY_OF_MONTH);

                 // Create a new instance of DatePickerDialog and return it
                 return new DatePickerDialog(getActivity(), this, year, month, day);
        }



            @Override
            public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
                 calendar.set(Calendar.YEAR,year);
                 calendar.set(Calendar.MONTH,monthOfYear);
                 calendar.set(Calendar.DAY_OF_MONTH,dayOfMonth);
                 userDate = userFormat.format(calendar.getTime());
                 sysDate = sysFormat.format(calendar.getTime());

       }
   }
}

Answer 1

解决了，我觉得很傻。

制作了重新加载地图的方法

import java.util.Scanner;
import java.util.ArrayList;

public class Practice {


    public static void main(String[] args) {
        bannerPrinter();
        getNum();
        int num = 0;
        ArrayList<String> products = productBuilder(num);
        boolean productGuess = getOrder(products);
        if (productGuess) {
            double price = getPrice();
            double tax = getTax(price);
            double total = getTotal(tax, price);
            printTotal(total);
        }
        else {
            System.out.print("Product not found.");
        }
    }

    public static void bannerPrinter() {

        System.out.println();
        System.out.println("******************************************");
        System.out.println("****** Welcome to my eCommerce app! ******");
        System.out.println("******************************************");
        System.out.println();
    }

    public static int getNum() {

        Scanner scnr = new Scanner(System.in);
        int num = 0;

        System.out.print("Enter the number of products: ");
        num = scnr.nextInt();

        return num;
    }

    public static ArrayList<String> productBuilder(int num) {

        Scanner scnr = new Scanner(System.in);
        String arrayNames = "";
        ArrayList<String> products = new ArrayList();

        for (int i = 0; i <= num; i++) {
            System.out.print("Enter the products: ");
            products.add(arrayNames);
        }
        return products;
    }

    public static boolean getOrder(ArrayList<String> products) {

        Scanner scnr = new Scanner(System.in);
        String guess = "";

        boolean productName = products.contains(guess);

        System.out.print("Enter a product: ");
        guess = scnr.nextLine();

        if(productName) {
            System.out.println();
            System.out.print("This product has been found.");
            System.out.println();
        }
        else {
            System.out.println();
        }

        return productName;
    }

    public static double getPrice() {

        double price = 0.0;
        price = (int)(Math.random() * 100);

        return price;
    }

    public static double getTax(double price) {

        double tax = 0.0;
        tax = price * 0.10;

        return tax;
    }

    public static double getTotal(double price, double tax) {

        double saleTotal = 0.0;
        saleTotal = price + tax;

        return saleTotal;
    }

    public static void printTotal(double saleTotal) {

        System.out.println("You total is $" + saleTotal + "0");
    }

}

然后使用public void reloadMap(){ SupportMapFragment supportMapFragment = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.map); supportMapFragment.getMapAsync(this); }

调用它

getActivity()