Android 如何在单个选项卡中增加日期？
我是android的新手。我的任务是创建一个android应用程序，其中一个标签可以无限次滑动。我的第一个屏幕必须显示当前日期，向前滑动时，它应该增加到明天的日期，依此类推；I don’我不知道如何实施。请建议和指导我的朋友 多谢各位 我的主要活动在这里Android 如何在单个选项卡中增加日期？,android,android-fragments,Android,Android Fragments,我是android的新手。我的任务是创建一个android应用程序，其中一个标签可以无限次滑动。我的第一个屏幕必须显示当前日期，向前滑动时，它应该增加到明天的日期，依此类推；I don’我不知道如何实施。请建议和指导我的朋友 多谢各位 我的主要活动在这里 public class MainActivity extends AppCompatActivity { /** * The {@link android.support.v4.view.PagerAdapter} tha
public class MainActivity extends AppCompatActivity {
/**
* The {@link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {@link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* {@link android.support.v4.app.FragmentStatePagerAdapter}.
*/
private SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {@link ViewPager} that will host the section contents.
*/
private ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
public PlaceholderFragment() {
}
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
TextView textView = (TextView) rootView.findViewById(R.id.section_label);
textView.setText(getString(R.string.section_format, getArguments().getInt(ARG_SECTION_NUMBER)));
return rootView;
}
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public int getCount() {
return 100;
}
@Override
public Fragment getItem(int position) {
Tab2 tab2=new Tab2();
return tab2;
}
@Override
public CharSequence getPageTitle(int position) {
return "SECTION 3";
}
}
}
public class Tab2 extends Fragment {
String strDate;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
for (int i = 0;i<=100;i++) {
if (i < 1) {
try {
Date myDate = sdf.parse("15/07/2017");
Calendar c = Calendar.getInstance();
c.setTime(myDate);
c.set(Calendar.DATE, c.get(Calendar.DATE) + 1);
Date newDate = c.getTime();
strDate = sdf.format(newDate);
} catch (ParseException e) {
e.printStackTrace();
}
}
else {
Date day = new Date();
strDate = sdf.format(new Date(day.getTime()));
}
}
return inflater.inflate(R.layout.tab2,container,false );
}
@Override
public void onStart() {
super.onStart();
TextView textView2 = getView().findViewById(R.id.textView2);
textView2.setText(strDate);
}
}
public class MainActivity extends AppCompatActivity {
/**
* The {@link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {@link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* {@link android.support.v4.app.FragmentStatePagerAdapter}.
*/
private SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {@link ViewPager} that will host the section contents.
*/
private ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
public PlaceholderFragment() {
}
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
TextView textView = (TextView) rootView.findViewById(R.id.section_label);
textView.setText(getString(R.string.section_format, getArguments().getInt(ARG_SECTION_NUMBER)));
return rootView;
}
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public int getCount() {
return 100;
}
@Override
public Fragment getItem(int position) {
Tab2 tab2=new Tab2();
return tab2;
}
@Override
public CharSequence getPageTitle(int position) {
return "SECTION 3";
}
}
}
public class Tab2 extends Fragment {
String strDate;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
for (int i = 0;i<=100;i++) {
if (i < 1) {
try {
Date myDate = sdf.parse("15/07/2017");
Calendar c = Calendar.getInstance();
c.setTime(myDate);
c.set(Calendar.DATE, c.get(Calendar.DATE) + 1);
Date newDate = c.getTime();
strDate = sdf.format(newDate);
} catch (ParseException e) {
e.printStackTrace();
}
}
else {
Date day = new Date();
strDate = sdf.format(new Date(day.getTime()));
}
}
return inflater.inflate(R.layout.tab2,container,false );
}
@Override
public void onStart() {
super.onStart();
TextView textView2 = getView().findViewById(R.id.textView2);
textView2.setText(strDate);
}
}
public类Tab2扩展了片段{
字符串strDate；
@可空
@凌驾
创建视图时的公共视图（LayoutFlater充气机、@Nullable ViewGroup容器、Bundle savedInstanceState）{
SimpleDataFormat sdf=新的SimpleDataFormat（“日/月/年”）；
对于（inti=0；i您可以使用片段的位置将日期添加到当前日期。
第一个片段的位置是0，所以将0天添加到日期。第二个片段的位置是1，所以将1天添加到日期，依此类推
下面是Tab2
片段代码：
public class Tab2 extends Fragment {
private int position;
public Tab2() {
}
public static Tab2 newInstance(int position) {
Tab2 fragment = new Tab2();
Bundle args = new Bundle();
args.putInt("position", position);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
position = getArguments().getInt("position");
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_t2, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
Calendar c = Calendar.getInstance();
c.add(Calendar.DAY_OF_MONTH, position);
String dt = sdf.format(c.getTime()).toString();
TextView textView2 = getView().findViewById(R.id.textView2);
textView2.setText(dt);
}
现在，在您的部分PageRadapter
的getItem
方法中，将position
发送到frament：
@Override
public Fragment getItem(int position) {
return Tab2.newInstance(position);
}