Question

我按照各种来源的所有步骤来获取列表视图但我的一个似乎没有显示任何东西。这个列表视图代码（如下所示）是通过一个标签片段管理器激活的，我不会在这里把它放在一起，因为这里已经有了很多代码，所以不会让你陷入困境。这很可能是ListFragment本身的问题，但我想它可能是适配器。

我发布的主要xml布局中的搜索视图完全没有显示任何内容。我可以在标签之间自由切换，没有崩溃，但我的任何列表视图中都没有显示任何内容。我有另一个列表，这是一个朋友列表（不包含在此代码片段中），并且使用通用视图持有者界面，并且一个不起作用，这表明问题很可能在我的ListFragment中，但我无法确定它。任何帮助表示赞赏，我希望有些人可以从中学到一些东西，谢谢。

这是我的设置类别列表适配器

package codeblox.com.listfragmentexample;

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.ToggleButton;

import java.util.ArrayList;
import codblox.com.listfragmentexample.R;

public class SettingsAdapter extends ArrayAdapter<Settings.SettingsCategories>
{
private final Activity context;
String[] text;
ArrayList<Settings.SettingsCategories> itemsCopy;

class ViewHolder
{
    public TextView txt;
    public CheckBox state;
    public ImageView settingImg;
    public EditText input;
    public ToggleButton toggle;
    public Button settingInfo; // click it to show what the setting does
}

public SettingsAdapter(Context context, ArrayList<Settings.SettingsCategories> items)
{
    super(context, R.layout.settings_category_row, items);
    this.context = (Activity) context;
    this.itemsCopy = items;
}

@Override
public View getView(int position, View convertView, ViewGroup parent)
{
    ViewHolder holder = new ViewHolder();
    int viewType = this.getItemViewType(position);

    if(convertView == null)
     {
     // inflate the GridView item layout
        LayoutInflater inflater = LayoutInflater.from(getContext());
        convertView = inflater.inflate(R.layout.settings_category_row, parent, false);
     // initialize the view holder
        holder = new ViewHolder();
        holder.settingImg = (ImageView) convertView.findViewById(R.id.settingCategoryImg);
        holder.txt = (TextView) convertView.findViewById(R.id.settingCategoryName);
        convertView.setTag(holder);
    } else {
 // recycle the already inflated view
        holder = (ViewHolder) convertView.getTag();
    }

    // fill data
    holder = (ViewHolder) convertView.getTag();
    String s = getItem(position).toString();
    holder.txt.setText(itemsCopy.get(position).getSettingText());
    holder.settingImg.setImageResource(itemsCopy.get(position).getImgResId());

    return convertView;
 }
}

这是我的列表片段

package codeblox.com.listfragmentexample
import android.content.res.Resources;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.util.ArrayList;

import codeblox.com.listfragmentexample.R;


public class Settings extends ListFragment implements View.OnLongClickListener
{

private ListView settingsList;
private ArrayList<SettingsCategories> mItems;

private ArrayAdapter<SettingsCategories> settingsAdapter;
private int numCategories;
String[] CategoryArray = new String[] {"Privacy and Security","Account","Networks","Camera Options","Storage","Accesibility","Features"};
int[] resIds = new int[] {R.drawable.security_settings_icon,R.drawable.account_settings_icon,
        R.drawable.network_settings_icon,R.drawable.camera_settings_icon,R.drawable.storage_settings_icon,
        R.drawable.accessibility_settings_icon,R.drawable.feature_settings_icon,};
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState)
{
    View settingsView = inflater.inflate(R.layout.settings, container, false);
    settingsList = (ListView)settingsView.findViewById(android.R.id.list);
    // initialize the items list
   return settingsView;
}

@Override
public void onViewCreated(View view, Bundle savedInstanceState)
{
    super.onViewCreated(view, savedInstanceState);
  // remove the dividers from the ListView of the ListFragment
    settingsList = getListView();
    settingsList.setDivider(null);
    mItems = new ArrayList<SettingsCategories>();
    Resources resources = getResources();

    for(int c = 0; c < numCategories; c++)
    {
        mItems.add(new SettingsCategories(CategoryArray[c],resIds[c]));
    }

   // initialize and set the list adapter
    // settingsAdapter = new SettingsAdapter(this.getActivity(), mItems);

    setListAdapter(new SettingsAdapter(getActivity(), mItems));
    settingsList.setAdapter(settingsAdapter);

}

public Settings()
{

  this.numCategories = CategoryArray.length;
}

@Override
public void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
}

@Override
public boolean onLongClick(View v)
{
    return false;
}
@Override
public void onListItemClick(ListView l, View v, int position, long id)
{
    Object i = l.getItemAtPosition(position);
}

public class SettingsCategories
{
  private String settingText;
  private int imgResId;

    SettingsCategories(String settingText,int imgResId)
  {
     this.settingText = settingText;
     this.imgResId = imgResId;
  }

   public String getSettingText()
    {
        return this.settingText;
    }
    public int getImgResId()
    {
        return this.imgResId;
    }
 }
}

最后这些是我的xml布局（第一个是主视图，第二个是列表中单个项目的视图

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
>
<SearchView
    android:id="@+id/searchFunction"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal" >
</SearchView>

 <ListView
   android:id="@android:id/list"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content">
 </ListView>
 </RelativeLayout>

这表示列表中的单个项目

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
>

<ImageView
    android:layout_width="52dp"
    android:layout_height="52dp"
    android:id="@+id/settingCategoryImg"
 />

<TextView
    android:layout_width="fill_parent"
    android:layout_height="52dp"
    android:text=""
    android:id="@+id/settingCategoryName"
    android:layout_alignParentTop="true"
    android:layout_toRightOf="@+id/settingCategoryImg"
 />
</RelativeLayout>

Answer 1

您正在设置null适配器，因此它不会刷新。你被评论初始化部分

检查以下方法：

@Override
public void onViewCreated(View view, Bundle savedInstanceState)
{
    super.onViewCreated(view, savedInstanceState);
  // remove the dividers from the ListView of the ListFragment
    settingsList = getListView();
    settingsList.setDivider(null);
    mItems = new ArrayList<SettingsCategories>();
    Resources resources = getResources();

    for(int c = 0; c < numCategories; c++)
    {
        mItems.add(new SettingsCategories(CategoryArray[c],resIds[c]));
    }

   // initialize and set the list adapter
    // settingsAdapter = new SettingsAdapter(this.getActivity(), mItems);

    setListAdapter(new SettingsAdapter(getActivity(), mItems));
    settingsList.setAdapter(settingsAdapter);

}

您正在使用ListFragement并再次膨胀布局。这不是一个好主意。当您扩展listfragment时，不需要对布局进行膨胀，并修改上述方法，如：

@Override
public void onViewCreated(View view, Bundle savedInstanceState)
{
    super.onViewCreated(view, savedInstanceState);
  // remove the dividers from the ListView of the ListFragment
    settingsList = getListView();
    settingsList.setDivider(null);
    mItems = new ArrayList<SettingsCategories>();
    Resources resources = getResources();

    for(int c = 0; c < numCategories; c++)
    {
        mItems.add(new SettingsCategories(CategoryArray[c],resIds[c]));
    }

   // initialize and set the list adapter
     settingsAdapter = new SettingsAdapter(this.getActivity(), mItems);

    //setListAdapter(new SettingsAdapter(getActivity(), mItems));
    settingsList.setAdapter(settingsAdapter);

}

Android ListView只显示但不会崩溃

1 个答案: