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我在一個頁面中有一個ViewPager活動，應該是EditText和其他頁面是TextView，從第一個片段獲取數據以顯示在第二個視圖中，但我正在努力，因爲知識的缺乏，我主要活動爲無法將數據從片段傳遞到ViewPager中的其他數據
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
viewPager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));
}
private class MyPagerAdapter extends FragmentPagerAdapter {
public MyPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int pos) {
switch(pos) {
case 0: return EditFragment.newInstance("FirstFragment, Instance 1");
case 1: {
Log.e("TAG", " is " + new EditFragment().getTag());
return PreviewFragment.newInstance(new EditFragment().getTag());
}
default: return EditFragment.newInstance("ThirdFragment, Default");
}
}
@Override
public int getCount() {
return 2;
}
}
}
主要佈局是
<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/viewpager"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
EditFragment是
public class EditFragment extends Fragment {
public EditFragment(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_editor, container, false);
EditText tv = (EditText) v.findViewById(R.id.content);
tv.setText(getArguments().getString("msg"));
return v;
}
public static EditFragment newInstance(String text) {
EditFragment f = new EditFragment();
Bundle b = new Bundle();
b.putString("msg", text);
f.setArguments(b);
return f;
}
}
PreviewFragment
public class PreviewFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_markdown, container, false);
TextView tvView = (TextView) v.findViewById(R.id.markdownView);
tvView.loadMarkdown(getArguments().getString("msg"));
return v;
}
public static PreviewFragment newInstance(String text) {
PreviewFragment f = new PreviewFragment();
Bundle b = new Bundle();
b.putString("msg", text);
f.setArguments(b);
return f;
}
}
那裏，我不知道如何從EditFragment數據傳遞到PreviewFragment，請幫助。
我是碎片的新手請幫助我。
UPDATE
我已經改變
public class PreviewFragment extends Fragment {
private TextView textView;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_markdown, container, false);
textView = (TextView) v.findViewById(R.id.title);// initialized here
return v;
}
public void b_updateText(String t){
Log.e("LOAD TXT", t);// Here I can get data Data is available
textView.setText(t); // but Here I get NPE, don't know why.
}
}
，但在這裏我得到NPE，不知道爲什麼。
和EditFragment是
public class EditFragment extends Fragment {
public EditFragment(){}
private static Bundle bundle = null;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_editor, container, false);
final EditText tv = (EditText) v.findViewById(R.id.content);
final PsgerActivity mainActivity = (PsgerActivity) getActivity();
mainActivity.message= tv.getText().toString();
tv.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
bundle = new Bundle();
bundle.putString("md", tv.getText().toString());
Log.e("BUNDLE", bundle.getString("md"));// Data is available
}
@Override
public void afterTextChanged(Editable editable) {
}
});
return v;
}
public static EditFragment newInstance() {
EditFragment f = new EditFragment();
f.setArguments(bundle);
return f;
}
}
MainActivity是
public class MainActivity extends AppCompatActivity {
public String message;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);
viewPager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
if (position == 1) {
PreviewFragment fragmentB = new PreviewFragment();
EditFragment ef = EditFragment.newInstance();
try{
Log.e("ACTIVITY", ef.getArguments().getString("md"));// Data is available
} catch (Exception e){
e.printStackTrace();
}
fragmentB.b_updateText(ef.getArguments().getString("md"));
}
}
@Override
public void onPageSelected(int position) {
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
}
private class MyPagerAdapter extends FragmentPagerAdapter {
public MyPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int pos) {
switch(pos) {
case 0: return EditFragment.newInstance();
case 1: return new PreviewFragment();
default: return EditFragment.newInstance();
}
}
@Override
public int getCount() {
return 2;
}
}
}
，但在這裏我得到NPE，不知道爲什麼。
請閱讀有關使用接口與活動片段進行通信的信息。 –
但是你爲什麼使用viewpager同時顯示和編輯選項？這個實現的實際目的是什麼？ –
當我們通過刷卡來更改碎片時，您想要傳輸數據嗎？ –