如何找到“最后一页”在一个视图寻呼机。或视图的总“数量”。 Android开发 [英] How to find the "last page" in a view pager. Or the total 'number' of views. Android Development
问题描述
感谢您的高级帮助。抱歉，如果这是一个非常愚蠢的问题，但我无法在其他地方找到它。
基本上，我想要的是确定我在ViewPager中设置的页面总数，就像在我的代码中一样。我已经尝试（在更高版本中）将size变量添加到f作为它的参数（参见FirstFragment）。这不是一个已知的数字，因为用户输入我将创建的表单（视图）的数量，并将其作为意图传递给FirstFragment。所以我试过了：
Thank you for your help in advanced. And sorry if this is a very silly question, but I cannot find it elsewhere. What I want, is basically, to determine the total amount of pages I have in my ViewPager when it is all set up, like in my code. I have tried (on a later version) adding the "size variable" to f as it's argument (see, FirstFragment). It's not a known number, as the user input's the number of forms (view's) I will create, and passes it to FirstFragment as an intent. So I have tried :
Fragment f = new UserFragment();
Bundle bundl = new Bundle();
bundl.putInt("pagenumbers", size);
f.setArguments(bundl);
lf.add(f);
在FirstFragment中。但是当UserFragment在pagenumbers下提取它的参数时，它返回0.
然后我试图访问存在于FragmentAdapter中的getCount（）方法，但是，我不知道如何解决这个问题，给定当我需要它时，我在UserFragment里面。
Inside FirstFragment. But when UserFragment extracts its arguments under "pagenumbers" it is returning 0. I then tried to gain access to the getCount() method that lives inside FragmentAdapter, however, I'm not sure how to go about this, given that I'm inside UserFragment when I need it.
我正在尝试做些什么可能有助于澄清，是我正在提取当前页面信息，我现在感谢我早些时候的职位和帮助过的人。现在我想查看currentpage == size（//是页数。在viewpager中的总视图数）。因此，在onClick方法中，您可以在UserFragment中看到，如果它是最后一页，则用户点击按钮转到下一页。我希望它跳转到另一个活动，它操作从所有表单收集的所有SparseArray数据。 （我需要有关如何将此SparseArray数据放入intent中的帮助，我可能会对此提出一个新问题......因为它不是很相关）。所以，如果你可以帮助我获得当前的工作尝试（如何正确地做到这一点），或者只是建议一种全新的方法，我很高兴。只要我能让它发挥作用！
What I'm trying to do maybe to help clarify, is I'm extracting "current page info" which I now have working thanks to an earlier post of mine and those whom helped. Now I want to see if "currentpage == size (//which is number of pages. Total views in the viewpager)". So in the onClick method you can see in UserFragment, if it's the last page, and the user hits the button to go to the next page. I want it to jump to another activity, where it manipulates all the SparseArray data that was collected from all the forms. (Which I need help on how to put this SparseArray data into an intent, I will probably make a new question with this ... as it's not very related). So if you could either assist me in getting my current attempts to work (how to do it properly) or just suggest an entirely new method I'm happy. As long as I can get it working!
非常感谢您提供的所有帮助。请帮忙！
Thank you very much for all your assistance, in advanced. Please help!
我的UserFragment.java ：
package com.example.thinice;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class UserFragment extends Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.layout_avgcalcform,
container, false);
final EditText markc = (EditText)rootView.findViewById(R.id.editTextASSMARK);
final EditText marktotc = (EditText)rootView.findViewById(R.id.editTextASSTOT);
final EditText assvalc = (EditText)rootView.findViewById(R.id.editTextASSWORTH);
int currentviewnum = ((FirstFragment) getActivity()).getPager().getCurrentItem();
String pagenum = Integer.toString(currentviewnum);
TextView tv = (TextView) rootView.findViewById(R.id.avg_testtv);
tv.setText(pagenum);
Button b = (Button) rootView.findViewById(R.id.button1);
b.setOnClickListener( new View.OnClickListener(){
public void onClick(View v){
int currentviewnum = ((FirstFragment) getActivity()).getPager().getCurrentItem();
((FirstFragment) getActivity()).saveData(new Question(markc.getText().toString(),marktotc.getText().toString(),assvalc.getText().toString()));
((FirstFragment) getActivity()).getPager().setCurrentItem(currentviewnum+1);
}
});
return rootView;
}
}
如果您需要要查看我的更多代码，请告诉我。但这真让我烦恼。
所以，如果有人可以帮助我，那就太棒了！
非常感谢您提前。
If you need to see any more of my code, please let me know. But this is really annoying me. So if anybody out there could help me, it would be fantastic! Thank you very much in advanced.
FragmentAdapter.java ：
package com.example.thinice;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.view.ViewGroup;
public class FragmentAdapter extends FragmentPagerAdapter{
private List<Fragment> fragments;
public FragmentAdapter(FragmentManager fragmentManager, ArrayList<Fragment> fragments) {
super(fragmentManager);
this.fragments = fragments;
}
@Override
public Fragment getItem(int position) {
//Bundle args = new Bundle();
//args.putInt("page_position", position+1);
//((Fragment) fragments).setArguments(args);
return this.fragments.get(position);
}
@Override
public void destroyItem (ViewGroup container, int position, Object object)
{
super.destroyItem(container, position, object);
}
@Override
public int getCount() {
return this.fragments.size();
}
}
FirstFragment.java（这是我的活动） ）：
package com.example.thinice;
import java.util.ArrayList;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.util.SparseArray;
import android.widget.Button;
public class FirstFragment extends FragmentActivity
{
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout_viewpager);
// Check whether the activity is using the layout version with
// the fragment_container FrameLayout. If so, we must add the first fragment
int size = getIntent().getExtras().getInt("numass1");
ViewPager vp = (ViewPager) findViewById(R.id.viewPager);
if (savedInstanceState != null) {
return;
}
ArrayList<Fragment> lf = new ArrayList<Fragment>();
for(int count=0; count<size; count ++){
Fragment f = new UserFragment();
lf.add(f);
}
FragmentAdapter hello = new FragmentAdapter(getSupportFragmentManager() , lf);
vp.setAdapter(hello);
// vp.setOffscreenPageLimit(size);
}
SparseArray<Question> questions = new SparseArray<Question>();
public void saveData(Question quest){
ViewPager vp = (ViewPager) findViewById(R.id.viewPager);
questions.put(vp.getCurrentItem(), quest);
}
public ViewPager getPager() {
ViewPager vp = (ViewPager) findViewById(R.id.viewPager);
return vp;
}
}
编辑：建议解决方案的LOGCAT文件：
07-06 20:51:50.241: D/AndroidRuntime(8151): Shutting down VM
07-06 20:51:50.241: W/dalvikvm(8151): threadid=1: thread exiting with uncaught exception (group=0x415a4ba8)
07-06 20:51:50.251: E/AndroidRuntime(8151): FATAL EXCEPTION: main
07-06 20:51:50.251: E/AndroidRuntime(8151): Process: com.example.thinice, PID: 8151
07-06 20:51:50.251: E/AndroidRuntime(8151): java.lang.NullPointerException
07-06 20:51:50.251: E/AndroidRuntime(8151): at com.example.thinice.UserFragment.onCreateView(UserFragment.java:34)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.support.v4.app.Fragment.performCreateView(Fragment.java:1500)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:927)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1467)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:472)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.support.v4.view.ViewPager.populate(ViewPager.java:1068)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.support.v4.view.ViewPager.populate(ViewPager.java:914)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1436)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.View.measure(View.java:16497)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.View.measure(View.java:16497)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
07-06 20:51:50.251: E/AndroidRuntime(8151): at com.android.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:327)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.View.measure(View.java:16497)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5125)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
07-06 20:51:50.251: E/AndroidRuntime(8151): at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2291)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.View.measure(View.java:16497)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1912)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1109)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1291)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:996)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5600)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.Choreographer.doCallbacks(Choreographer.java:574)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.Choreographer.doFrame(Choreographer.java:544)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.os.Handler.handleCallback(Handler.java:733)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.os.Handler.dispatchMessage(Handler.java:95)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.os.Looper.loop(Looper.java:136)
07-06 20:51:50.251: E/AndroidRuntime(8151): at android.app.ActivityThread.main(ActivityThread.java:5001)
07-06 20:51:50.251: E/AndroidRuntime(8151): at java.lang.reflect.Method.invokeNative(Native Method)
07-06 20:51:50.251: E/AndroidRuntime(8151): at java.lang.reflect.Method.invoke(Method.java:515)
07-06 20:51:50.251: E/AndroidRuntime(8151): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
07-06 20:51:50.251: E/AndroidRuntime(8151): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
07-06 20:51:50.251: E/AndroidRuntime(8151): at dalvik.system.NativeStart.main(Native Method)
推荐答案
您应该使用ViewPager.getAdapter（）。getCount（）getAdapter（）方法返回为其提供页面的对象ViewPager。
You should be using ViewPager.getAdapter().getCount() The getAdapter() method returns the object that supplies the pages for the ViewPager.
这篇关于如何找到“最后一页”在一个视图寻呼机。或视图的总“数量”。 Android开发的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
