如何使用简单适配器在列表视图（android）中使用/获取任何行项的位置而不通过单击侦听器获取它？

Question

public class MainActivity extends AppCompatActivity {
    ListView list;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        list=(ListView) findViewById(R.id.listview);

        String[] months={"January","Feburary","March","April","May","June","July","August","September","October","November","December"};

        ArrayAdapter<String> adapter=new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,android.R.id.text1,months);
        list.setAdapter(adapter);

//i want here to use the positions of rows of listview

//Actually i want that whenever activity open, background color of odd listview items should be of black color and even should be of white background color.

//with simple adapter and without using any click listener.

}
}

Answer 1

您所需要的只是getItemViewType，它允许您在recyclerview中夸大多个视图。

在您的适配器中，您可以写：

//Returns the view type of the item at position for the purposes of view recycling.
  @Override
  public int getItemViewType(int position) {
      if (position%2 == 0) {
          //set even color
      } else {
          //set odd color
      }
      return -1;
  }

见this和this

Answer 2

尝试这个想法

for ( int i = 0 ; i < listView.getCount() ; i++){
    View v = getViewByPosition(i,listView);
    // then check if i is odd set background color with what u want
    v.setBackgroundColor(Color.Parse("#000000"));
}

public View getViewByPosition(int position, ListView listView) {
    final int firstListItemPosition = listView.getFirstVisiblePosition();
    final int lastListItemPosition =firstListItemPosition + 
    listView.getChildCount() - 1;

    if (position < firstListItemPosition || position > lastListItemPosition ) {
    return listView.getAdapter().getView(position, 
    listView.getChildAt(position), listView);
    } else {
    final int childIndex = position - firstListItemPosition;
    return listView.getChildAt(childIndex);
    }
}

Answer 3

    public class BlackWhiteAdapter extends ArrayAdapter<String> {

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
       if (convertView == null) {
          convertView = LayoutInflater.from(getContext()).inflate(android.R.layout.simple_list_item_1, parent, false);
       }
       String txt = getItem(position);  
       TextView tvMonth = (TextView) convertView.findViewById(android.R.id.text1);
       tvMonth.setTextColor((position%2==0) 0xFF00000 : 0xFFFFFFFF);
       return convertView;
   }
}

Answer 4

当您在AdapterView上设置Addap（）时，例如ListView，在内部调用getView（），并在AdapterView中填充从其返回的视图覆盖getView方法，您可以获得选定的值

String[] months={"January","Feburary","March","April","May","June","July","August","September","October","November","December"};

          String selectedMonth ;
        ArrayAdapter<String> adapter=new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1,android.R.id.text1,months){
            @NonNull
            @Override
            public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
                View v = super.getView(position, convertView, parent);
                 v.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    selectedMonth = months[position];
                }
            });
                return v;
            }
        };