我是Android开发的新手,我最近的一个项目遇到了问题。我有一个listfragment作为一个活动的一部分,它工作并加载我放入它的测试信息,但是,有一个加载微调器,无论我尝试什么都不会消失。这是图像: Perpetual Loading Bar。 这是我的代码:
MainActivity.java
package com.projects.nick.pheme;
import android.support.v4.app.FragmentManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FragmentManager fragmanager = getSupportFragmentManager();
FragmentTransaction fragtrans = fragmanager.beginTransaction();
setContentView(R.layout.activity_main);
//setting the home screen
FragmentList listFrag = new FragmentList();
fragtrans.add(R.id.FirstFragment, listFrag);
fragtrans.commit();
}
}
activity_main.xml中
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="0dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:background="@color/primary_material_light"
android:orientation="horizontal"
android:weightSum="3"
android:id="@+id/linearLayout">
<ImageButton
android:layout_width="0dp"
android:layout_height="match_parent"
android:src="@drawable/hometestdonotuse"
android:adjustViewBounds="true"
android:scaleType="fitCenter"
android:layout_weight="1" />
<ImageButton
android:layout_width="0dp"
android:layout_height="match_parent"
android:src="@drawable/hometestdonotuse"
android:adjustViewBounds="true"
android:scaleType="fitCenter"
android:layout_weight="1" />
<ImageButton
android:layout_width="0dp"
android:layout_height="match_parent"
android:src="@drawable/hometestdonotuse"
android:adjustViewBounds="true"
android:scaleType="fitCenter"
android:layout_weight="1"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_above="@+id/linearLayout"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true">
<fragment
android:id="@+id/FirstFragment"
android:name="android.support.v4.app.ListFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1" />
</LinearLayout>
</RelativeLayout>
FragmentList.java
package com.projects.nick.pheme;
import android.content.Context;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.ListFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import java.util.ArrayList;
public class FragmentList extends ListFragment{
private ArrayList<NewsCard> cardArray = new ArrayList<NewsCard>();
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.list_fragment, container, false);
ListView listView = (ListView) view.findViewById(android.R.id.list);
Context context = getActivity().getApplicationContext();
//TODO get rid of this and have the actual news articles show up
NewsCard testCard = new NewsCard("Nick invents the best app ever", "Nick's Mom");
NewsCard secondCard = new NewsCard("This is a test", "Nicks dad");
cardArray.add(0,testCard);
cardArray.add(1,secondCard);
MainAdapter adapter = new MainAdapter(context, cardArray);
listView.setAdapter(adapter);
return view;
}
}
list_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:weightSum="1">
<ListView
android:id="@android:id/list"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
MainAdapter.java
package com.projects.nick.pheme;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import java.util.ArrayList;
public class MainAdapter extends ArrayAdapter<NewsCard> {
public MainAdapter(Context context, ArrayList<NewsCard> elements) {
super(context, 0, elements);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
//get the data
NewsCard card = getItem(position);
// Check if view is being reused, otherwise inflate
if (convertView == null) {
convertView =
LayoutInflater.from(getContext()).inflate(R.layout.card_list, parent, false);
}
TextView cardSource = (TextView)
convertView.findViewById(R.id.sourceArticle);
TextView cardTitle = (TextView)
convertView.findViewById(R.id.titleArticle);
// populate the data into the template view using the data object
cardSource.setText(card.getSource());
cardTitle.setText(card.getTitle());
return convertView;
}
}
NewsCard类只是我用来保存信息的基本类,它只有一个构造函数,并且有两个用于字符串参数的访问器方法。
如果我遗失某些东西或某些不清楚的地方,请告诉我。我是stackoverflow的新手。谢谢!
答案 0 :(得分:0)
您必须使用ListFragment.setListAdapter()将列表与适配器相关联。不要直接调用ListView.setAdapter(),否则将跳过重要的初始化。
在FragmentList
而不是致电:
listView.setAdapter(adapter);
呼叫
setListAdapter(adapter);
编辑:
另一个问题(我认为)是添加两个FragmentList
的实例。
而不是
<fragment
android:id="@+id/FirstFragment"
android:name="android.support.v4.app.ListFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1" />
使用:
<FrameLayout
android:id="@+id/FirstFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1" />