Android listView 在错误的地方添加动态 View

Question

我有自定义适配器扩展 ListView 的 BaseAdapter。 ListView 有一个 LinearLayout，我正在尝试根据特定条件动态添加 View 。现在的问题是，它在错误的行中添加了 View ，有时两个 View 同时添加到一行中。这是 ListView 适配器布局的 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="100dip"
        android:baselineAligned="false"
        android:orientation="horizontal" >

            <LinearLayout
                android:id="@+id/dynamic_layout"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="0.3"
                android:orientation="horizontal" >
            </LinearLayout>

            <LinearLayout
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="0.7"
                android:orientation="vertical" >

                <TextView
                    android:id="@+id/groupName_tv"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="Group1"
                    android:textColor="@color/white"
                    android:textSize="18sp" />

                <TextView
                    android:id="@+id/groupContacts_tv"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="a, b , c"
                    android:textColor="@color/white"
                    android:textSize="16sp" />
            </LinearLayout>

    </LinearLayout>

在我的适配器中，我试图将 View 动态添加到@id dynamic_layout。这是我的适配器的 getView 方法:

    @Override
    public View getView(final int position, View converView, ViewGroup arg2) {
        // TODO Auto-generated method stub
        View view;
        TextView group_name;
        LinearLayout dynamic_layout;
        final TextView contacts_names;
        ViewHolder viewHolder;


        // Log.e("size in adapter ", getCount() + " size");
        if (converView == null) {
            converView = this.inflater.inflate(resource, arg2, false);

            group_name = (TextView) converView.findViewById(R.id.groupName);
            dynamic_layout = (LinearLayout) converView.findViewById(R.id.dynamic_layout);
            contacts_names = (TextView) converView
                    .findViewById(R.id.groupContacts);
            viewHolder = new ViewHolder(group_name, dynamic_layout, contacts_names);
            converView.setTag(viewHolder);

        } else {
            //view = converView;

            viewHolder = (ViewHolder) converView.getTag();

            group_name = viewHolder.group_name;
            dynamic_layout = viewHolder.layout;
            contacts_names = viewHolder.contacts_names;

        }

        /*
         *  bind the data to the view object
         */
        group_name.setText(g_names.get(position));

        LayoutInflater vi = (LayoutInflater) c.getApplicationContext()
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        if (group_map.get(g_names.get(position)).size() == 1) {
            View v = vi.inflate(R.layout.one_item_view, null);

            TextView textView = (TextView) v.findViewById(R.id.group_tv);
            textView.setText("one Item");

            ((LinearLayout) dynamic_layout).addView(v);


        }else if (group_map.get(g_names.get(position)).size() == 2) {
            View v = vi.inflate(R.layout.two_items_view, null);

            TextView textView = (TextView) v
                    .findViewById(R.id.two_group_tv1);
            textView.setText("left Item ");

            TextView textView2 = (TextView) v
                    .findViewById(R.id.two_group_tv2);
            textView2.setText("right Item ");

            ((LinearLayout) dynamic_layout).addView(v);


        }

        return converView;
    }

}  

Answer 1

当 listview 中的行变得可见时，系统将调用 getView。第一次 converView 将为 null。您需要创建一个新 View 并将其返回。执行此操作后，下一次 getView 将使用您返回的上一个 View 进行调用。因为你的行没有变化，所以返回相同的 View 是安全的。

在您的原始代码中，if (converView == null) {...} 中没有所有内容，因此您不必要地创建新 View 并使用 ( (LinearLayout) dynamic_layout).addView(v); 每次。

@Override
public View getView(final int position, View converView, ViewGroup arg2) {

    if (converView == null) {
        converView = this.inflater.inflate(resource, arg2, false);

        TextView group_name = (TextView) converView.findViewById(R.id.groupName);
        LinearLayout dynamic_layout = (LinearLayout) converView.findViewById(R.id.dynamic_layout);
        TextView contacts_names = (TextView) converView.findViewById(R.id.groupContacts);
        ViewHolder viewHolder = new ViewHolder(group_name, dynamic_layout, contacts_names);
        converView.setTag(viewHolder);

        // bind the data to the view object
        group_name.setText(g_names.get(position));

        LayoutInflater vi = (LayoutInflater) c.getApplicationContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        if (group_map.get(g_names.get(position)).size() == 1) {
            View v = vi.inflate(R.layout.one_item_view, null);

            TextView textView = (TextView) v.findViewById(R.id.group_tv);
            textView.setText("one Item");

            ((LinearLayout) dynamic_layout).addView(v);

        } else if (group_map.get(g_names.get(position)).size() == 2) {
            View v = vi.inflate(R.layout.two_items_view, null);

            TextView textView = (TextView) v.findViewById(R.id.two_group_tv1);
            textView.setText("left Item ");

            TextView textView2 = (TextView) v.findViewById(R.id.two_group_tv2);
            textView2.setText("right Item ");

            ((LinearLayout) dynamic_layout).addView(v);
        }
    }
    return converView;
}