android - CustomListAdapter中的CustomListAdapter()无法应用

Question

我是 android 的新手，我正在尝试创建一个应用程序来根据他们的状态显示人员，在应用程序中我使用带有 fragment 的抽屉导航。

当我试图列出特定类别的人时，我遇到了错误。即

Error:(50, 57) error: incompatible types: Past cannot be converted to Activity
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output
Error:Execution failed for task ':app:compileDebugJavaWithJavac'.

Compilation failed; see the compiler error output for details.

我收到错误“无法应用 CustomListAdapter 中的 CustomListAdapter()”

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


  public class Past extends Fragment {

ListView list;
String[] itemname ={
        "John",
        "Mike",
        "Ria",
        "jack",
        "leo",

};

Integer[] imgid={
        R.drawable.pic1,
        R.drawable.pic2,
        R.drawable.pic3,
        R.drawable.pic4,
        R.drawable.pic5,
};

public Past() {
    // Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_past, container, false);

    CustomListAdapter adapter=new CustomListAdapter(this, itemname, imgid);
        //here am getting  an error
    list=(ListView)getView().findViewById(R.id.list);
    list.setAdapter(adapter);

    /*list.setOnItemClickListener(new AdapterView.OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                                int position, long id) {
            // TODO Auto-generated method stub
            String Slecteditem= itemname[+position];
            Toast.makeText(getApplicationContext(), Slecteditem, Toast.LENGTH_SHORT).show();

        }
    });*/
}

   @Override
    public void onDestroy() {
       super.onDestroy();
   }
 }

CustomListAdapter.java 代码如下

 import android.app.Activity;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ArrayAdapter;
 import android.widget.ImageView;
 import android.widget.TextView;


 public class CustomListAdapter extends ArrayAdapter<String> {

 private final Activity context;
 private final String[] itemname;
 private final Integer[] imgid;

public CustomListAdapter(Activity context, String[] itemname, Integer[] imgid) {
    super(context, R.layout.mylist, itemname);
    // TODO Auto-generated constructor stub

    this.context=context;
    this.itemname=itemname;
    this.imgid=imgid;
}

public View getView(int position,View view,ViewGroup parent) {
    LayoutInflater inflater=context.getLayoutInflater();
    View rowView=inflater.inflate(R.layout.mylist, null,true);

    TextView txtTitle = (TextView) rowView.findViewById(R.id.item);
    ImageView imageView = (ImageView) rowView.findViewById(R.id.icon);
    TextView extratxt = (TextView) rowView.findViewById(R.id.textView1);

    txtTitle.setText(itemname[position]);
    imageView.setImageResource(imgid[position]);
    extratxt.setText("Description "+itemname[position]);
    return rowView;

   };
 }

从 MainActivity 调用的 fragment 如下所示

     else if(i==1){
        switch (j){

            case 0:
                Past past = new Past();
                fragmentTransaction = fragmentManager.beginTransaction();
                fragmentTransaction.replace(R.id.frameholde,past);
                fragmentTransaction.commit();
                break;

            case 1:
                Current current = new Current();
                fragmentTransaction = fragmentManager.beginTransaction();
                fragmentTransaction.replace(R.id.frameholde, current);
                fragmentTransaction.commit();
                break;

            case 2:
                Area area = new Area();
                fragmentTransaction = fragmentManager.beginTransaction();
                fragmentTransaction.replace(R.id.frameholde, area);
                fragmentTransaction.commit();
                break;

        }

Answer 1

除了评论中指出的问题外，您在设置适配器之前从 onCreateView() 方法返回，因此无法访问代码问题。

设置对膨胀 View 的引用，使用该 View 找到 ListView，然后在方法结束时返回 View :

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

        CustomListAdapter adapter = new CustomListAdapter(getActivity(), itemname, imgid);

        list=(ListView) rootView.findViewById(R.id.list); //modified
        list.setAdapter(adapter);

        return rootView; //added
    }