Android-节日短信送祝福（UI篇：2-展示节日列表的Framgment的创建）

在上一篇文章中，已经基本实现了主布局，接下来，我们将加以完善——在这里，要实现上篇文章中提到过的FestivalCategoryFragment

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下面是布局文件的实现：
fragment_festival_category.xml

<GridView xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/id_gv_festival_category"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:numColumns="3"    android:horizontalSpacing="3dp"    android:padding="16dp"    android:verticalSpacing="2dp" ></GridView>

布局呢很简单，就是一个GridView

以及GridView的item的布局：
item_festival.xml

<android.support.v7.widget.CardView    xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="wrap_content" >    <TextView        android:id="@+id/id_tv_festival_name"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:background="#ffffff"        android:gravity="center"        android:padding="8dp" /></android.support.v7.widget.CardView>

这里为了增加立体感，在外层设置一个CardView
但是要添加相应的Library Dependency -> com.android.support:cardview-v7

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public class FestivalCategoryFragment extends Fragment {    public static final String ID_FESTIVAL="FestivalId";    private GridView mGridView;    private ArrayAdapter<Festival> mAdapter;    private LayoutInflater mInflater;    @Nullable    @Override    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {        return inflater.inflate(R.layout.fragment_festival_category, container,                false);//注意：是"包名.R"    }    @Override    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {        mInflater = LayoutInflater.from(getActivity());        mGridView = (GridView) view.findViewById(R.id.id_gv_festival_category);        mAdapter = new ArrayAdapter<Festival>(                getActivity(), -1, FestivalLab.getInstance().getFestivals()) {            @Override            public View getView(int position, View convertView, ViewGroup parent) {                if (convertView == null) {                    convertView = mInflater.inflate(R.layout.item_festival,                            parent, false);                }                TextView tv = (TextView) convertView                        .findViewById(R.id.id_tv_festival_name);                tv.setText(getItem(position).getName());                return convertView;            }        };        mGridView.setAdapter(mAdapter);        mGridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {            @Override            public void onItemClick(AdapterView<?> parent, View view,                                    int position, long id) {                Intent intent=new Intent(getActivity(), ChooseMsgActivity.class);                intent.putExtra(ID_FESTIVAL,mAdapter.getItem(position).getId());                startActivity(intent);            }        });    }}

需要注意的是，这里所继承的父类Fragment是来自android.support.v4.app，不要弄错为android.app

（@Nullable 参数可为null）

可以看到，FestivalCategoryFragment的实现比较的容易，还末尾处实现了GridView的点击事件，点击之后跳转到相应的ChooseMsgActivity，用于选择事先提供的祝福短信。