Question

我正在尝试创建一个自定义ListView，我想我正确地制作了我的适配器。我对android很新，并且不太了解所有带有视图和适配器等的概念。

我的代码全部是在片段中完成的，而不是主要的活动。我不知道这是否会影响您将内容传递给列表的方式。

我正在尝试显示从JSON格式的字符串中获取的信息。当我运行我的应用程序时，列表永远不会显示，我不知道它是否因为我传递了错误的视图或类似的东西。它没有崩溃。

personal_profile_fragment：

public class Personal_Profile_Fragment extends Fragment {

private charAdapter adapter;

ListView list;
ArrayList<charactors> charactorList;

public Personal_Profile_Fragment() {
    // Required empty public constructor
}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View v = inflater.inflate(R.layout.fragment_personal__profile_, container, false);

    Bundle bundle = getArguments();
    String JSON = bundle.getString("JSON");

    parseJson(JSON);

    list = (ListView)v.findViewById(R.id.list);
    charactorList = new ArrayList<charactors>();
    adapter = new charAdapter(getContext(), charactorList);
    list.setAdapter(adapter);

    return v;
}

private void parseJson(String json) {
    try {
        JSONObject chars = new JSONObject(json);
        JSONArray charArray = chars.getJSONArray("heroes");

        for (int i = 0; i<charArray.length(); i++) {
            JSONObject realCharacter = charArray.getJSONObject(i);

            charactors charactor = new charactors();
            charactor.setName(realCharacter.getString("name"));
            charactor.setClassType(realCharacter.getString("class"));
            charactor.setLevel(realCharacter.getString("level"));
            charactor.setParagonLevel(realCharacter.getString("paragonLevel"));
            charactor.setHardcore(realCharacter.getString("hardcore"));
            charactor.setSeasonal(realCharacter.getString("seasonal"));

            charactorList.add(charactor);
        }

    } catch(Exception e) {

    }
}

}

personal_profile.xml

<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:id="@+id/personalProfileFragment"
tools:context="com.hfad.diablo3assistant.Personal_Profile_Fragment">

<!-- TODO: Update blank fragment layout -->

<android.support.constraint.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ListView
        android:id="@+id/list"
        android:layout_width="368dp"
        android:layout_height="551dp"
        tools:layout_editor_absoluteX="8dp"
        tools:layout_editor_absoluteY="8dp" />
</android.support.constraint.ConstraintLayout>
</FrameLayout>

row.xml：

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

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginStart="17dp"
        android:layout_marginTop="34dp"
        android:text="TextView" />

    <TextView
        android:id="@+id/classType"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignStart="@+id/name"
        android:layout_below="@+id/name"
        android:layout_marginTop="12dp"
        android:text="TextView" />

    <TextView
        android:id="@+id/level"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignStart="@+id/classType"
        android:layout_below="@+id/classType"
        android:layout_marginTop="15dp"
        android:text="TextView" />

    <TextView
        android:id="@+id/paragonLevel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignStart="@+id/level"
        android:layout_below="@+id/level"
        android:layout_marginTop="15dp"
        android:text="TextView" />

    <TextView
        android:id="@+id/hardcore"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignEnd="@+id/paragonLevel"
        android:layout_below="@+id/paragonLevel"
        android:layout_marginTop="13dp"
        android:text="TextView" />

    <TextView
        android:id="@+id/seasonal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignStart="@+id/hardcore"
        android:layout_below="@+id/hardcore"
        android:layout_marginTop="20dp"
        android:text="TextView" />

</RelativeLayout>
</LinearLayout>

charactors class：

public class charactors {
private String name;
private String classType;
private String level;
private String paragonLevel;
private String hardcore;
private String seasonal;

public charactors() {

}



public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getClassType() {
    return classType;
}

public void setClassType(String classType) {
    this.classType = classType;
}

public String getLevel() {
    return level;
}

public void setLevel(String level) {
    this.level = level;
}

public String getParagonLevel() {
    return paragonLevel;
}

public void setParagonLevel(String paragonLevel) {
    this.paragonLevel = paragonLevel;
}

public String getHardcore() {
    return hardcore;
}

public void setHardcore(String hardcore) {
    this.hardcore = hardcore;
}

public String getSeasonal() {
    return seasonal;
}

public void setSeasonal(String seasonal) {
    this.seasonal = seasonal;
}

}

Charactor适配器：

public class charAdapter extends ArrayAdapter<charactors> {
private final Context context;
private final ArrayList<charactors> charactorsArrayList;

public charAdapter(Context context, ArrayList<charactors> charactorsArrayList) {

    super(context, R.layout.row, charactorsArrayList);

    this.context = context;
    this.charactorsArrayList = charactorsArrayList;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    // 1. Create inflater
    LayoutInflater inflater = (LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    // 2. Get rowView from inflater
    View rowView = inflater.inflate(R.layout.row, parent, false);

    // 3. Get the two text view from the rowView
    TextView name = (TextView) rowView.findViewById(R.id.name);
    TextView classType = (TextView) rowView.findViewById(R.id.classType);
    TextView level = (TextView) rowView.findViewById(R.id.level);
    TextView paragonLevel = (TextView) rowView.findViewById(R.id.paragonLevel);
    TextView hardcore = (TextView) rowView.findViewById(R.id.hardcore);
    TextView seasonal = (TextView) rowView.findViewById(R.id.seasonal);

    // 4. Set the text for textView
    name.setText("Name: "+charactorsArrayList.get(position).getName());
    classType.setText("Class: "+charactorsArrayList.get(position).getClassType());
    level.setText("Level: "+charactorsArrayList.get(position).getLevel());
    paragonLevel.setText("Paragon: "+charactorsArrayList.get(position).getParagonLevel());
    hardcore.setText("Hardcore: "+charactorsArrayList.get(position).getHardcore());
    classType.setText("Seasonal: "+charactorsArrayList.get(position).getSeasonal());

    // 5. retrn rowView
    return rowView;
}
}

Answer 1

您的适配器的getView()实施效率低下，但它看起来功能正确。我认为问题只是onCreateView()中的一个简单错误：

parseJson(JSON);
...
charactorList = new ArrayList<charactors>();
adapter = new charAdapter(getContext(), charactorList);

看起来你正在解析JSON字符串，然后通过将new ArrayList分配给charactorList来立即抛弃解析工作。

实际上，看得更深一点，当charactorList正在运行时parseJson()似乎是空的（但是catch块正在隐藏它）。所以你只想重新安排一下这段代码：

charactorList = new ArrayList<charactors>();
parseJson(JSON);
...
adapter = new charAdapter(getContext(), charactorList);

自定义ListView无法正常工作

1 个答案: