在日期選擇器

Question

計算50天如何在Andriod的日期選擇器中輸入的天計算50天。

例如，如果用戶選擇23/02/2013那麼什麼WLD是從第50天THT XX/XX/XXXX同樣100天第200天像明智的第1000天，請幫我在這邏輯

Answer 1

至於我明白你的問題，你可以嘗試做這樣的事情：

// this const is 24 hours in milliseconds: 24 hours in day, 60 min. in one hour, 60 sec. in one min., 1000 ms. in one sec. 
private static final int TWENTY_FOUR_HOURS = 24 * 60 * 60 * 1000; 
//... 
Date dateYouChose; 
Date dateYouChosePlus50Days = new Date(dateYouChose.getTime() + (50 * TWENTY_FOUR_HOURS)); 

更新時間：

所以，也許這將是對你有好處（但要小心，我沒有測試此代碼，也許我犯了一個錯誤，我n東西）：

final DatePicker datePicker; 

final Button btnDisplayCelebrationTimes; 

final TextView txtDatePlus50; 
final TextView txtDatePlus100; 

// ... 

btnDisplayCelebrationTimes.setOnClickListener(new View.OnClickListener() { 

    @Override 
    public void onClick(View v) { 
     final SimpleDateFormat dateFormat = new SimpleDateFormat("dd.MM.yyyy"); 

     final GregorianCalendar gregorianCalendar; 

     gregorianCalendar = new GregorianCalendar(datePicker.getYear(), datePicker.getMonth(), 
       datePicker.getDayOfMonth()); 
     gregorianCalendar.add(Calendar.DAY_OF_MONTH, 50); 
     final Date datePlus50 = gregorianCalendar.getTime(); 

     txtDatePlus50.setText(dateFormat.format(datePlus50)); 

     gregorianCalendar = new GregorianCalendar(datePicker.getYear(), datePicker.getMonth(), 
       datePicker.getDayOfMonth()); 
     gregorianCalendar.add(Calendar.DAY_OF_MONTH, 100); 
     final Date datePlus100 = gregorianCalendar.getTime(); 

     txtDatePlus100.setText(dateFormat.format(datePlus100)); 
    } 
}); 

Answer 2

使用下面的簡單代碼來動態添加天數。

int Days = 50; // this is the input . you can change it in argument. the format of the date also changeable as per your requirement. 

     try 
     { 
     Date date = null; 
     String str = "2013-06-04";   
     SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");  
     date = formatter.parse(str); 
     Calendar calendar = Calendar.getInstance(); 
     calendar.setTime(date); 
     calendar.add(Calendar.DATE,Days);  
     System.out.println("" + formatter.format(calendar.getTime())); 
     } 
     catch (Exception e) 
     { 
      e.printStackTrace(); 
     } 

希望這可以幫助你。

編輯。

你好，這是完整的工作代碼。

import java.text.SimpleDateFormat; 
import java.util.Calendar; 
import java.util.Date; 

import android.app.Activity; 
import android.app.DatePickerDialog; 
import android.app.Dialog; 
import android.os.Bundle; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.DatePicker; 
import android.widget.TextView; 

public class MyAndroidAppActivity extends Activity { 

    private TextView tvDisplayDate; 
    private DatePicker dpResult; 
    private Button btnChangeDate; 

    private int year; 
    private int month; 
    private int day; 

    static final int DATE_DIALOG_ID = 999; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     setCurrentDateOnView(); 
     addListenerOnButton(); 

    } 

    // display current date 
    public void setCurrentDateOnView() { 

     tvDisplayDate = (TextView) findViewById(R.id.tvDate); 
     dpResult = (DatePicker) findViewById(R.id.dpResult); 

     final Calendar c = Calendar.getInstance(); 
     year = c.get(Calendar.YEAR); 
     month = c.get(Calendar.MONTH); 
     day = c.get(Calendar.DAY_OF_MONTH); 

     // set current date into textview 
     tvDisplayDate.setText(new StringBuilder() 
       // Month is 0 based, just add 1 
       .append(month + 1).append("-").append(day).append("-") 
       .append(year).append(" ")); 

     // set current date into datepicker 
     dpResult.init(year, month, day, null); 

    } 

    public void addListenerOnButton() { 

     btnChangeDate = (Button) findViewById(R.id.btnChangeDate); 

     btnChangeDate.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) { 

       showDialog(DATE_DIALOG_ID); 

      } 

     }); 

    } 

    @Override 
    protected Dialog onCreateDialog(int id) { 
     switch (id) { 
     case DATE_DIALOG_ID: 
      // set date picker as current date 
      return new DatePickerDialog(this, datePickerListener, year, month, 
        day); 
     } 
     return null; 
    } 

    private DatePickerDialog.OnDateSetListener datePickerListener = new DatePickerDialog.OnDateSetListener() { 

     // when dialog box is closed, below method will be called. 
     public void onDateSet(DatePicker view, int selectedYear, 
       int selectedMonth, int selectedDay) { 
      year = selectedYear; 
      month = selectedMonth; 
      day = selectedDay; 

      String str= year+"-"+(month+1)+"-"+day; 
      System.out.println(" rrrrrr " +str); 
      tvDisplayDate.setText(str); // this is the current date. 

      tvDisplayDate.setText(" Old Date" + str + "After adding 50 days" +dateadding(50, str)); 
      // set selected date into datepicker also 
      dpResult.init(year, month, day, null); 

     } 
    }; 

    String dateadding(int DaystoAdd,String Date) 
    { 
     int Days = DaystoAdd; // this is the input . you can change it in argument. the format of the date also changeable as per your requirement. 
String finaldate=""; 
     try 
     { 
     Date date = null; 
     String str = Date;   
     SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");  
     date = formatter.parse(str); 
     Calendar calendar = Calendar.getInstance(); 
     calendar.setTime(date); 
     calendar.add(Calendar.DATE,Days);  
     finaldate= formatter.format(calendar.getTime()); 
     } 
     catch (Exception e) 
     { 
      e.printStackTrace(); 
     } 
     return finaldate; 
    } 


} 

設計線條

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical" > 

    <Button 
     android:id="@+id/btnChangeDate" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="Change Date" /> 

    <TextView 
     android:id="@+id/lblDate" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="Current Date (M-D-YYYY): " 
     android:textAppearance="?android:attr/textAppearanceLarge" /> 

    <TextView 
     android:id="@+id/tvDate" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="" 
     android:textAppearance="?android:attr/textAppearanceLarge" /> 

    <DatePicker 
     android:id="@+id/dpResult" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" /> 

</LinearLayout>