Question

我正在使用Android应用程序，似乎无法在运行应用程序时显示我的listView。我已经开始使用一些xml，但我仍然经常使用新的和Android更新，所以教程不断变得过时。实际的java代码对我来说似乎很好，我看不出太大的区别那里。我真的可以用一双额外的眼睛，也许有一些我不知道的东西。

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;

    public class MainActivity extends AppCompatActivity {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);
       }

    @Override
   public boolean onCreateOptionsMenu(Menu menu) {
            // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
     return true;
        }

      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
       // Handle action bar item clicks here. The action bar will
       // automatically handle clicks on the Home/Up button, so long
      // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

      //noinspection SimplifiableIfStatement
            if (id == R.id.action_settings) {
                return true;
            }

            return super.onOptionsItemSelected(item);
        }
    }



import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.text.Layout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.FrameLayout;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;




/**
 * A placeholder fragment containing a simple view.
 */
public class MainActivityFragment extends Fragment {

    public MainActivityFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        String[] forecastArray = {
                "Today, colder than bumblefuck",
                "Friday, condsider moving",
                "Saturday, not even gonna bother",
                "Sunday, Partly Cloudy",
                "Monday, Hell Froze over",
                "Tuesday, Cloudy with a chance of meatballs",
                "Wednesday,Light Showers"
        };
        List<String> weekForeCast = new ArrayList<String>(
                Arrays.asList(forecastArray));

        ArrayAdapter<String> bindIt= new ArrayAdapter<String>(getActivity(),R.layout.list_item_forecast,R.id.list_item_forecast_textview,weekForeCast);

        ListView listView = (ListView) inflater.inflate(R.layout.fragment_main, container, false).findViewById(R.id.listview_forecast);
        listView.setAdapter(bindIt);

        return inflater.inflate(R.layout.fragment_main, container, false);
    }
}


<FrameLayout 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:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivityFragment">

    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/listview_forecast">
    </ListView>

</FrameLayout>

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:minHeight="?android:attr/listPreferredItemHeight"
    android:gravity="center_vertical"
    android:id ="@+id/list_item_forecast_textview"
    android:visibility="visible"
    android:enabled="false">

</TextView>

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:id="@+id/fragment"
    android:name="com.alesterlewis.sunshine.app.MainActivityFragment"
    tools:layout="@layout/fragment_main" android:layout_width="match_parent"
    android:layout_height="match_parent" />

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.alesterlewis.sunshine.app" >

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Answer 1

问题是您在从onCreateView返回时正在充气新视图。因此，您设置适配器和列表视图的那个丢失了。这是错误。

首先在视图中为片段的布局充气

View view = inflater.inflate(R.layout.fragment_main, container, false);

然后初始化它的组件，在这里你可以设置列表视图适配器等，如果你有更多的视图，初始化相同。

ArrayAdapter<String> bindIt= new ArrayAdapter<String>(getActivity(),R.layout.list_item_forecast,R.id.list_item_forecast_textview,weekForeCast);

        ListView listView = (ListView) view.findViewById(R.id.listview_forecast);
        listView.setAdapter(bindIt);

并最终返回最初被编辑和处理的相同视图！

Answer 2

您是否为列表设置了适配器？也许你的适配器列表由于某种原因是空的。

<强>更新

尝试预测视图创建：

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_main, container, false);
        String[] forecastArray = {
                "Today, colder than bumblefuck",
                "Friday, condsider moving",
                "Saturday, not even gonna bother",
                "Sunday, Partly Cloudy",
                "Monday, Hell Froze over",
                "Tuesday, Cloudy with a chance of meatballs",
                "Wednesday,Light Showers"
        };
        List<String> weekForeCast = new ArrayList<String>(
                Arrays.asList(forecastArray));

        ArrayAdapter<String> bindIt= new ArrayAdapter<String>(getActivity(),R.layout.list_item_forecast,R.id.list_item_forecast_textview,weekForeCast);

        ListView listView = (ListView) view.findViewById(R.id.listview_forecast);
        listView.setAdapter(bindIt);

        return view;
    }

无法显示我的列表视图

2 个答案: