我有3个片段：Frag1，Frag2和Frag3。当我打开我的应用程序时，Frag1会在第一页上加载并显示一个网页。第二页上的Frag2应显示从同一网页提取的图像。第3页上的Frag3应显示从同一页面提取的一些文本。 在每个片段中，我能够提取并放置内容。 以下代码面临的问题是：
下面是FragmentActivity和Fragment实现。
如果我从菜单选项函数changeDate()中选择一个新日期，即案例R.id.date_settings，我能帮助我如何刷新所有片段。
以下是主要功能的摘要。一切都很好，但上面提到的问题。
public class MainActivity extends FragmentActivity {
public int year;
public int month;
public int day;
public String date_string;
public static String urlString;
public static String urlImageString;
ViewPager mViewPager;
SectionsPagerAdapter mSectionsPagerAdapter;
FragmentManager fragmentManager;
TextView pageTitleText;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
final Calendar c = Calendar.getInstance();
year = c.get(Calendar.YEAR);
month = c.get(Calendar.MONTH);
day = c.get(Calendar.DAY_OF_MONTH);
createDateString();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public class SectionsPagerAdapter extends FragmentStatePagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
Fragment fragment;
Bundle args = new Bundle();
switch(position) {
case 0:
fragment = new Frag1();
args.putInt(FullPageFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
case 1:
fragment = new Frag2();
args.putInt(ImageFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
case 2:
fragment = new Frag3();
args.putInt(MessageFragment.ARG_SECTION_NUMBER, position + 1);
fragment.setArguments(args);
return fragment;
default:
return null;
}
}
@Override
public int getCount() {
// Show 3 total pages.
return 3;
}
@Override
public CharSequence getPageTitle(int position) {
Locale l = Locale.getDefault();
switch (position) {
case 0:
return getString(R.string.title_section1).toUpperCase(l);
case 1:
return getString(R.string.title_section2).toUpperCase(l);
case 2:
return getString(R.string.title_section3).toUpperCase(l);
}
return null;
}
}
public static class Frag1 extends Fragment {
public static final String ARG_SECTION_NUMBER = "section_number";
WebView webView;
public FullPageFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main,
container, false);
webView.getSettings().setCacheMode( WebSettings.LOAD_DEFAULT );
webView.loadUrl(urlString);
return rootView;
}
@Override
public void onSaveInstanceState(Bundle outState) {
// TODO Auto-generated method stub
super.onSaveInstanceState(outState);
};
};
public static class Frag2 extends Fragment {
public static final String ARG_SECTION_NUMBER = "section_number";
ImageLoader imgLoader; // class that downloads and display image also has save option
ImageView imgview;
int loader;
public ImageFragment() {
};
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.image_view,
container, false);
loader = R.drawable.ic_launcher;
imgview = (ImageView) rootView.findViewById(R.id.imageView1);
imgLoader = new ImageLoader( super.getActivity().getApplicationContext());
imgLoader.DisplayImage(urlImageString, loader, imgview, file_string);
}
Button imgBtn = (Button) rootView.findViewById(R.id.button1);
imgBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Log.i(TAG, "onClick: Saving file: < " + file_string + ">");
imgLoader.SaveImage(file_string);
}
});
return rootView;
}
@Override
public void onSaveInstanceState(Bundle outState) {
// TODO Auto-generated method stub
super.onSaveInstanceState(outState);
};
}
public static class Frag3 extends Fragment {
public static final String ARG_SECTION_NUMBER = "section_number";
WebView webView;
public String finalUrl;
public MessageFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.message_view,
container, false);
webView.loadData(finalMsg, "text/html", "UTF-8");
return rootView;
};
@Override
public void onSaveInstanceState(Bundle outState) {
// TODO Auto-generated method stub
super.onSaveInstanceState(outState);
}
};
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.date_settings:
changeDate();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
public void changeDate() {
final Calendar c = Calendar.getInstance();
year = c.get(Calendar.YEAR);
month = c.get(Calendar.MONTH);
day = c.get(Calendar.DAY_OF_MONTH);
DatePickerDialog dpd = new DatePickerDialog(this,
new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year1,
int monthOfYear, int dayOfMonth) {
//txtDate.setText(dayOfMonth + "-" + (monthOfYear + 1) + "-" + year);
year = year1;
month = monthOfYear;
day = dayOfMonth;
Log.i(TAG, "onDateSet: date has changes resetting values");
createDateString();
createUrl();
createUrImage();
createFileString();
}
}, year, month, day);
dpd.show();
};
public void createUrl() {
//implementaion is here
}
public void createUrImage() {
//implementaion is here
}
public void createFileString() {
//implementaion is here
}
}