如何使用ViewPager实施Firebase? [英] How to implement Firebase with ViewPager?
本文介绍了如何使用ViewPager实施Firebase?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
将Firebase与ViewPager一起使用的最佳方法是什么.
What is the best way to use firebase with ViewPager.
预期产量
如何将ViewPager与Firebase一起使用，以便它通知Firebase该位置并相应地获取并附加数据?
How can I use ViewPager with Firebase such that it notifies the firebase for the position and gets and attaches the data accordingly?
Person.java
public class Person {
private String name;
private String email;
private String hobby;
public Person(){
}
public Person(String name , String email , String hobby){
this.name= name;
this.email = email;
this.hobby = hobby;
}
public void setName(String name) {
this.name = name;
}
public void setEmail(String email) {
this.email = email;
}
public void setHobby(String hobby) {
this.hobby = hobby;
}
public String getName() {
return name;
}
public String getEmail() {
return email;
}
public String getHobby() {
return hobby;
}
}
MainActivity.java
public class MainActivity extends AppCompatActivity {
private ViewPager viewPager;
// private FirebaseAuth mAuth;
List<Person> person;
private Context context;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
person = new ArrayList<>();
// mAuth = FirebaseAuth.getInstance();
context = this;
viewPager = (ViewPager) findViewById(R.id.pagerView);
viewPager.setAdapter(new MyPagerAdapter(getSupportFragmentManager(), person, context));
}
class MyPagerAdapter extends FragmentPagerAdapter {
String[] tabsArray;
private List<Person> personInAdapter = new ArrayList<>();
private Context context;
// int icons[] = {R.drawable.white_home, R.drawable.white_heart,
// R.drawable.white_star, R.drawable.white_heart, R.drawable.white_star};
public MyPagerAdapter(FragmentManager fm, List<Person> person, Context context) {
super(fm);
personInAdapter = person;
this.context = context;
tabsArray = getResources().getStringArray(R.array.TABS);
}
// @Override
// public CharSequence getPageTitle(int position) {
// return tabsArray[position];
// }
@Override
public Fragment getItem(int position) {
return MyFragment.getInstance(position );
}
@Override
public int getCount() {
return personInAdapter.size();
}
}
}
MyFragment.java
MyFragment.java
public class MyFragment extends Fragment {
private TextView upperText;
private TextView lowerText;
List<Person> personInAdapter = new ArrayList<>();
private Context context;
private DatabaseReference databaseReference;
public static MyFragment getInstance(int position) {
MyFragment myFragment = new MyFragment();
Bundle args = new Bundle();
args.putInt("position", position);
myFragment.setArguments(args);
return myFragment;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_my, container, false);
upperText = (TextView) view.findViewById(R.id.myFragmentUpperText);
lowerText = (TextView) view.findViewById(R.id.myFragmentLowerText);
databaseReference = FirebaseUtil.getBaseRef().child("Person");
int i = getArguments().getInt("position");
ValueEventListener postListener = new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
// Get Post object and use the values to update the UI
for (DataSnapshot personSnapshot: dataSnapshot.getChildren()) {
Person person = personSnapshot.getValue(Person.class);
upperText.setText(person.getName());
lowerText.setText(person.getEmail());
Log.i("Data In Person ", person.toString());
}
// [END_EXCLUDE]
}
@Override
public void onCancelled(DatabaseError databaseError) {
// Getting Post failed, log a message
// [START_EXCLUDE]
}
};
databaseReference.addValueEventListener(postListener);
// Bundle bundle = getArguments();
// if (bundle != null) {
// textView.setText("The value is" +i);
// }
return view;
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
}
我已经尝试过使用FirebaseRecyclerView来尝试使用Firebase，并在自定义Recyclerview中实现相同的功能，并且它就像魅力一样
I have tried firebase with the FirebaseRecyclerView and implemented the same in a custom Recyclerview and it worked like charm
FirebaseRecyclerAdapter<Blog, BlogViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Blog, BlogViewHolder>(
Blog.class,
R.layout.blog_row,
BlogViewHolder.class,
mDatabaseReference
) {
@Override
protected void populateViewHolder(BlogViewHolder viewHolder, Blog model, int position) {
viewHolder.setDesc(model.getDesc());
viewHolder.setTitle(model.getTitle());
viewHolder.setImage(getApplicationContext(), model.getImageUrl());
mGoogleNow.progressiveStop();
mGoogleNow.setVisibility(View.GONE);
}
};
mBlogList.setAdapter(firebaseRecyclerAdapter);
}
public void LogoutFromFirebase(View view) {
mAuth.signOut();
}
public static class BlogViewHolder extends RecyclerView.ViewHolder {
NetworkImageView networkImageView;
ImageLoader imageLoader;
View mView;
public BlogViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
public void setTitle(String title) {
TextView sTitle = (TextView) mView.findViewById(R.id.TitleTextView);
sTitle.setText(title);
}
public void setDesc(String desc) {
TextView sDesc = (TextView) mView.findViewById(R.id.descriptionTextView);
sDesc.setText(desc);
}
public void setImage(Context context, String image) {
networkImageView = (NetworkImageView) mView.findViewById(R.id.imageBlogPost);
imageLoader = CustomVolleyRequest.getInstance(context)
.getImageLoader();
imageLoader.get(image, ImageLoader.getImageListener(networkImageView,
R.drawable.crop_image_menu_crop, android.R.drawable
.ic_dialog_alert));
networkImageView.setImageUrl(image, imageLoader);
// Picasso.with(context).load(image).into(networkImageView);
}
}
推荐答案
最后，在SO和其他各种博客上苦苦挣扎之后，我得以将从Firebase获得的数据用于与ViewPager非常相似的内容: Horizontal RecyclerView和LinearSnapHelper.您需要覆盖findTargetSnapPosition，然后完成.
Finally after toiling hard on SO and various other blogs I was able to use the data I get from the Firebase into something very similar to ViewPager : Horizontal RecyclerView with LinearSnapHelper. You need to override findTargetSnapPosition and then you are done.
首先将RecyclerView添加到您的活动/片段"
<android.support.v7.widget.RecyclerView
android:layout_below="@+id/sign_in_button"
android:layout_width="match_parent"
android:orientation="horizontal"
android:id="@+id/blog_list"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
在我的情况下，我在RecyclerView
blog_row.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_margin="15dp"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical">
<com.android.volley.toolbox.NetworkImageView
android:id="@+id/imageBlogPost"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:paddingBottom="15dp"
android:src="@drawable/common_google_signin_btn_text_light_normal" />
<TextView
android:id="@+id/TitleTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="20dp"
android:text="Post Title Here"
android:textSize="16sp" />
<TextView
android:id="@+id/descriptionTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Post Description Here"
android:paddingBottom="15dp"
android:textSize="14sp" />
</LinearLayout>
</android.support.v7.widget.CardView>
在您的活动/片段中
private RecyclerView mBlogList;
LinearLayoutManager layoutManager
= new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
mBlogList = (RecyclerView) findViewById(R.id.blog_list);
mBlogList.setHasFixedSize(true);
mBlogList.setLayoutManager(layoutManager);
LinearSnapHelper snapHelper = new LinearSnapHelper() {
@Override
public int findTargetSnapPosition(RecyclerView.LayoutManager lm, int velocityX, int velocityY) {
View centerView = findSnapView(lm);
if (centerView == null)
return RecyclerView.NO_POSITION;
int position = lm.getPosition(centerView);
int targetPosition = -1;
if (lm.canScrollHorizontally()) {
if (velocityX < 0) {
targetPosition = position - 1;
} else {
targetPosition = position + 1;
}
}
if (lm.canScrollVertically()) {
if (velocityY < 0) {
targetPosition = position - 1;
} else {
targetPosition = position + 1;
}
}
final int firstItem = 0;
final int lastItem = lm.getItemCount() - 1;
targetPosition = Math.min(lastItem, Math.max(targetPosition, firstItem));
return targetPosition;
}
};
snapHelper.attachToRecyclerView(mBlogList);
最后一步是将适配器设置为RecyclerView
mBlogList.setAdapter(firebaseRecyclerAdapter);
使用此方法，我们可以像这样获得ViewPager效果.
Using this we can get ViewPager Effect Like this.
这篇关于如何使用ViewPager实施Firebase?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！
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