当我使用 DatePicker 在 Android 中选择新日期时，日期未更改

Question

在我的程序中，我想在获取当前日期后从用户那里获取当前日期文本视图想要在 100 天后自动显示所选日期。

当我第一次运行我的应用程序时，我选择 15-12-2015 文本视图显示 24-03-2016 自动。

当我将日期更改为接下来的 3 天时，即选择 18-12-2015 文本视图显示相同的日期（24-03-2016）

这是我的代码： 活动.xml

<EditText
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/editText"
    android:layout_below="@id/textView"
    android:editable="false"
   android:hint="Select the Date "
    />

<Button
    android:layout_width="50px"
    android:layout_height="50px"
    android:layout_below="@+id/textView"
    android:layout_toRightOf="@+id/editText"
    android:background="@drawable/calender"
    android:layout_alignBottom="@+id/editText"
    android:layout_alignRight="@+id/textView"
    android:layout_alignEnd="@+id/textView"
    android:id="@+id/button"
    />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:text="Large Text"
    android:id="@+id/textView3"
    android:layout_below="@+id/editText"
    android:layout_centerHorizontal="true" />

MainActivity.java

public class MainActivity extends ActionBarActivity implements View.OnClickListener {
    private Button ib;
    private Calendar cal;
    private int day;
    private int month;
    private int year;
    private EditText et;
    private TextView display;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ib = (Button) findViewById(R.id.button);
        cal = Calendar.getInstance();
        day = cal.get(Calendar.DAY_OF_MONTH);
        month = cal.get(Calendar.MONTH);
        year = cal.get(Calendar.YEAR);
        et = (EditText) findViewById(R.id.editText);
        display = (TextView) findViewById(R.id.textView3);
        ib.setOnClickListener((View.OnClickListener) this);

    }
@Override
    public void onClick(View v) {
        showDialog(0);
    }
    @Override
    @Deprecated
    protected Dialog onCreateDialog(int id) {
        return new DatePickerDialog(this, datePickerListener, year, month, day);
    }

    private DatePickerDialog.OnDateSetListener datePickerListener = new DatePickerDialog.OnDateSetListener() {
        public void onDateSet(DatePicker view, int selectedYear,
                              int selectedMonth, int selectedDay) {
             et.setText(selectedDay + " / " + (selectedMonth + 1) + " / "
                    + selectedYear);
 SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
            Calendar c = Calendar.getInstance();
           // c.setTime(dtStartDate);
            c.add(Calendar.DATE, 100);  // number of days to add
            String dt = sdf.format(c.getTime());  // dt is now the new date
            display.setText(dt);
        }
    };

Answer 1

试试这个：-

activity.xml :-

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="70dp"
        android:onClick="setDate"
        android:text="@string/date_button_set" />

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="24dp"
        android:text="@string/date_label_set"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/button1"
        android:layout_marginTop="66dp"
        android:layout_toLeftOf="@+id/button1"
        android:text="@string/date_view_set"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignRight="@+id/button1"
        android:layout_below="@+id/textView2"
        android:layout_marginTop="72dp"
        android:text="@string/date_selected"
        android:textAppearance="?android:attr/textAppearanceMedium" />
</RelativeLayout>

mainactivity.java :-

import android.app.DatePickerDialog;
import android.app.Dialog;
import android.support.v4.app.DialogFragment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import java.util.Calendar;

public class MainActivity extends AppCompatActivity {
    private DatePicker datePicker;
    private Calendar calendar;
    private TextView dateView;
    private int year, month, day;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        dateView = (TextView) findViewById(R.id.textView3);
        calendar = Calendar.getInstance();
        year = calendar.get(Calendar.YEAR);

        month = calendar.get(Calendar.MONTH);
        day = calendar.get(Calendar.DAY_OF_MONTH);
        showDate(year, month + 1, day);
    }
    @SuppressWarnings("deprecation")
    public void setDate(View view) {
        showDialog(999);
        Toast.makeText(getApplicationContext(), "ca", Toast.LENGTH_SHORT)
                .show();
    }

    @Override
    protected Dialog onCreateDialog(int id) {
        // TODO Auto-generated method stub
        if (id == 999) {
            return new DatePickerDialog(this, myDateListener, year, month, day);
        }
        return null;
    }

    private DatePickerDialog.OnDateSetListener myDateListener = new DatePickerDialog.OnDateSetListener() {
        @Override
        public void onDateSet(DatePicker arg0, int arg1, int arg2, int arg3) {
            // TODO Auto-generated method stub
            // arg1 = year
            // arg2 = month
            // arg3 = day
            showDate(arg1, arg2+1, arg3);
        }
    };

    private void showDate(int year, int month, int day) {
        dateView.setText(new StringBuilder().append(day).append("/")
                .append(month).append("/").append(year));
    }



}

Answer 2

您没有使用日期选择器提供的日期。

试试这个：

    public void onDateSet(DatePicker view, int selectedYear, int selectedMonth, int selectedDay) {
             et.setText(selectedDay + " / " + (selectedMonth + 1) + " / "
                    + selectedYear);
 SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
            Calendar c = Calendar.getInstance();
            c.set(selectedYear, selectedMonth, selectedDay); //set the date here
           // c.setTime(dtStartDate);
            c.add(Calendar.DATE, 100);  // number of days to add
            String dt = sdf.format(c.getTime());  // dt is now the new date
            display.setText(dt);
        }

更新： 将“selectedMonth+1”更改为“selectedMonth”