Viewpager编辑？(Viewpager Edit?)

Viewpager编辑？(Viewpager Edit?)

我有点新的Android和我试图自定义Android工作室的默认视图分页器。 。 我试图获得查看寻呼机的页码，例如为每个页面设置不同的图像。

package blabla.example.com.bla; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentPagerAdapter; import android.support.v4.view.ViewPager; import android.support.v7.app.AppCompatActivity; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ImageView; import android.widget.TextView; 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); } /** * 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))); ImageView levelImage = (ImageView) rootView.findViewById(R.id.imageView3); if (!ARG_SECTION_NUMBER.equals("1")) { levelImage.setImageResource(R.drawable.example1); } else if (!ARG_SECTION_NUMBER.equals("2")) { levelImage.setImageResource(R.drawable.example2); } else if (!ARG_SECTION_NUMBER.equals("3")) { levelImage.setImageResource(R.drawable.example3); } else if (!ARG_SECTION_NUMBER.equals("4")) { levelImage.setImageResource(R.drawable.example4); } else { levelImage.setImageResource(R.drawable.example5); } 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 Fragment getItem(int position) { // getItem is called to instantiate the fragment for the given page. // Return a PlaceholderFragment (defined as a static inner class below). return PlaceholderFragment.newInstance(position + 1); } @Override public int getCount() { // Show 5 total pages. return 5; } @Override public CharSequence getPageTitle(int position) { switch (position) { case 0: return "SECTION 1"; case 1: return "SECTION 2"; case 2: return "SECTION 3"; case 3: return "SECTION 4"; case 4: return "SECTION 5"; } return null; } } }

你可以看到我到目前为止试过这个:)）

ImageView levelImage = (ImageView) rootView.findViewById(R.id.imageView3); if (!ARG_SECTION_NUMBER.equals("1")) { levelImage.setImageResource(R.drawable.example51); } else if (!ARG_SECTION_NUMBER.equals("2")) { levelImage.setImageResource(R.drawable.example2); } else if (!ARG_SECTION_NUMBER.equals("3")) { levelImage.setImageResource(R.drawable.example3); } else if (!ARG_SECTION_NUMBER.equals("4")) { levelImage.setImageResource(R.drawable.example4); } else { levelImage.setImageResource(R.drawable.example5); }

但它不起作用。 我该怎么办？

i'm kinda new to android and i'm trying to customize the android studio's default view pager. . i'm trying to get view pager's page number and for example set different image for each page.

package blabla.example.com.bla; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentPagerAdapter; import android.support.v4.view.ViewPager; import android.support.v7.app.AppCompatActivity; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ImageView; import android.widget.TextView; 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); } /** * 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))); ImageView levelImage = (ImageView) rootView.findViewById(R.id.imageView3); if (!ARG_SECTION_NUMBER.equals("1")) { levelImage.setImageResource(R.drawable.example1); } else if (!ARG_SECTION_NUMBER.equals("2")) { levelImage.setImageResource(R.drawable.example2); } else if (!ARG_SECTION_NUMBER.equals("3")) { levelImage.setImageResource(R.drawable.example3); } else if (!ARG_SECTION_NUMBER.equals("4")) { levelImage.setImageResource(R.drawable.example4); } else { levelImage.setImageResource(R.drawable.example5); } 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 Fragment getItem(int position) { // getItem is called to instantiate the fragment for the given page. // Return a PlaceholderFragment (defined as a static inner class below). return PlaceholderFragment.newInstance(position + 1); } @Override public int getCount() { // Show 5 total pages. return 5; } @Override public CharSequence getPageTitle(int position) { switch (position) { case 0: return "SECTION 1"; case 1: return "SECTION 2"; case 2: return "SECTION 3"; case 3: return "SECTION 4"; case 4: return "SECTION 5"; } return null; } } }

and as you can see i tried this so far :))

ImageView levelImage = (ImageView) rootView.findViewById(R.id.imageView3); if (!ARG_SECTION_NUMBER.equals("1")) { levelImage.setImageResource(R.drawable.example51); } else if (!ARG_SECTION_NUMBER.equals("2")) { levelImage.setImageResource(R.drawable.example2); } else if (!ARG_SECTION_NUMBER.equals("3")) { levelImage.setImageResource(R.drawable.example3); } else if (!ARG_SECTION_NUMBER.equals("4")) { levelImage.setImageResource(R.drawable.example4); } else { levelImage.setImageResource(R.drawable.example5); }

but it's not working. so should i do?

最满意答案

变量ARG_SECTION_NUMBER包含一个String ，您只是将它用作查找getArguments()包中的值的键。 所以你可能应该改变你的代码是这样的：

if (getArguments().getInt(ARG_SECTION_NUMBER) == 1) { ... } else if (getArguments().getInt(ARG_SECTION_NUMBER) == 2) { ... }

当然，更好的解决方案是将图像资源ID直接放入包中，而不是仅仅放入节号，然后创建一个巨大的if / else树。 像这样的东西：

public static PlaceholderFragment newInstance(int sectionNumber, int drawableId) { PlaceholderFragment fragment = new PlaceholderFragment(); Bundle args = new Bundle(); args.putInt(ARG_SECTION_NUMBER, sectionNumber); args.putInt(ARG_DRAWABLE_ID, drawableId); fragment.setArguments(args); return fragment; } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { ... ImageView levelImage = (ImageView) rootView.findViewById(R.id.imageView3); levelImage.setImageResource(getArguments().getInt(ARG_DRAWABLE_ID)); return rootView; }

The variable ARG_SECTION_NUMBER holds a String that you're just using as a key to look up values in the getArguments() bundle. So you should probably change your code to be like this:

if (getArguments().getInt(ARG_SECTION_NUMBER) == 1) { ... } else if (getArguments().getInt(ARG_SECTION_NUMBER) == 2) { ... }

Of course, an even better solution would be to put the image resource id into the bundle directly, rather than just putting a section number in and then creating a huge if/else tree. Something like this:

public static PlaceholderFragment newInstance(int sectionNumber, int drawableId) { PlaceholderFragment fragment = new PlaceholderFragment(); Bundle args = new Bundle(); args.putInt(ARG_SECTION_NUMBER, sectionNumber); args.putInt(ARG_DRAWABLE_ID, drawableId); fragment.setArguments(args); return fragment; } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { ... ImageView levelImage = (ImageView) rootView.findViewById(R.id.imageView3); levelImage.setImageResource(getArguments().getInt(ARG_DRAWABLE_ID)); return rootView; }