Android listview项目更改背景颜色

Question

我无法更改列表视图项的背景颜色。

protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.info_layout);
    ListView listView;
    listView = (ListView) findViewById(R.id.infolistView);
    final String[] values = new String[] { "TO1", "TO2", "TO3" };
    ArrayAdapter<String> adapter =
        new ArrayAdapter<String>(this,
                                 android.R.layout.simple_list_item_1,
                                 android.R.id.text1,
                                 values);
    listView.setAdapter(adapter);

    // This is not make anything , why ?
    View vi=adapter.getView(0, null, null);
    vi.setBackgroundColor(Color.YELLOW);

listView.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view,
                        int position, long id) {
                //But here is running good
                view.setBackgroundColor(Color.RED);}
    });

Answer 1

你所做的只是获取一个填充了位置数据的视图实例，然后在调用该方法后死掉并被垃圾收集。

要更改列表中的实际视图，您必须从适配器更改颜色并编写自定义适配器，或者让颜色以该状态开始。

基本上getView 不会从视图列表中获取，而只是创建一个新视图，除非您将其传递给视图。

Answer 2

您必须创建自定义适配器来更改项目的背景颜色。

这是自定义适配器的示例：

public class PaListAdapter  extends BaseAdapter{
        private LayoutInflater mInflater;

         private ArrayList<String> platevalue = new ArrayList<String>();

           ViewHolder holder;
        public PaListAdapter(Context context,ArrayList<String> value)
        {
            // Cache the LayoutInflate to avoid asking for a new one each time.
            mInflater = LayoutInflater.from(context);



            //mycontext = context;
            platevalue.clear();
            platevalue =value;



        }


        public int getCount() 
        {
            return platevalue.size();
        }

        public Object getItem(int position) 
        {
            return position;
        }

        public long getItemId(int position) 
        {
            return position;
        }

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





            if (convertView == null) 
            {
                 convertView = mInflater.inflate(R.layout.select_dialog, null);

                holder = new ViewHolder();
                holder.hTransID =(TextView) convertView.findViewById(R.id.txtChoice);

                holder.ch   =(CheckBox) convertView.findViewById(R.id.chk);


                convertView.setTag(holder);
            }
            else 
            {
                holder = (ViewHolder) convertView.getTag();
            }

            holder.hTransID.setText(platevalue.get(position));




            return convertView;
        }

        static class ViewHolder 
        {      
              TextView    hTransID;


        }
    }


select_dialog.xml


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:descendantFocusability="blocksDescendants"
 android:background="#000000"
    >

    <TextView
        android:id="@+id/txtChoice"

        android:layout_gravity="center_vertical|left"
        android:gravity="center_vertical|left"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" 
        android:textColor="#000000"/> 

</LinearLayout>

在 Activity 类中。定义如下：

   simpleefficientadapter efficientadapter;

   efficientadapter=new simpleefficientadapter(CLASSNAME.this, VALUES);
   listView.setAdapter(efficientadapter);

Answer 3

您可以创建 listView 项目的实例并使用接受整数的getChildAt() 方法。然后设置视图实例背景颜色 -

View focusedChild = listView.getChildAt(r);
focusedChild.setBackgroundColor(Color.RED);