GridView,ExpandableListView,AutoCompleteTextView和Spinner

1、GridView

gridview 和昨天说的listview相似，不同的是，gridview可以设置多行显示。
结合昨天listview与gridview总结出使用的步骤（以gridview为例）;

<1>新建module工程，会产生一个MainActivity和layout下的main_grid.xml文件。如下所示：这个文件我理解成是整体的构架，这里面可以写ListView或者GridView。然后设置背景颜色或图片，宽和长等等。

//整体构架（layout下的xml）
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context="com.my.administrator.mywidget.GridActivity">

 <GridView
     android:id="@+id/gridview"//注意看此地址
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:numColumns="3">//gridview可以设置三列

 </GridView>

</RelativeLayout>

如上所写，整体的构架是这样的

还需要在layout下写一个xml文件，我理解成是数据的布局文件，数据条的背景颜色，宽度等等在这里面调整

//布局（layout下的xml)
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center">//数据条的背景颜色，宽度等等在这里面调整
    <ImageView//一张图片
        android:id="@+id/imageview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@mipmap/flower_mei"/>
    <TextView//图片的名字
        android:id="@+id/textview_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="名字"/>

</LinearLayout>

每个数据的布局是这样的

<2>接下来先在MainActivity中初始化gridview

 protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_grid);//对应整体构架
        mGridView = (GridView) findViewById(R.id.gridview);//对应构架文件xml中的id

<3>新建包modle，在其下新建一个类，比如在这里建一个Flower类

//Flower类 包含属性和set get方法，构造函数
public class Flower {
    private String name;
    private int img;
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getImg() {
        return img;
    }

    public void setImg(int img) {
        this.img = img;
    }

    public Flower(String name, int img) {
        this.name = name;
        this.img = img;

    }
}

<4>新建包adapter，在其下新建对应的adapter，比如在这里新建MyGridAdapter

//继承BaseAdapter ，重写四个方法
public class MyGridAdapter extends BaseAdapter {
    private LayoutInflater mFlater;
    private List<Flower> mFlower;

    public MyGridAdapter(LayoutInflater mFlater, List<Flower> mFlower) {
        this.mFlater = mFlater;
        this.mFlower = mFlower;
    }

    @Override
    public int getCount() {
        return mFlower.size();
    }

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

    @Override
    public long getItemId(int position) {
        return position;
    }
//用到了viewholder，处理缓存机制
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
         ViewHolder vh = null;
        if (convertView == null) {
            convertView = mFlater.inflate(R.layout.item_grid, null);//对应layout中的布局文件
            vh = new ViewHolder();
            vh.imageview = (ImageView) convertView.findViewById(R.id.imageview);
            vh.textview = (TextView) convertView.findViewById(R.id.textview_name);
            convertView.setTag(vh);
        } else {
            vh = (ViewHolder) convertView.getTag();
        }
        Flower flower = mFlower.get(position);
        vh.imageview.setImageResource(flower.getImg());
        vh.textview.setText(flower.getName());
        return convertView;
    }
    class ViewHolder{
        ImageView imageview;
        TextView textview;
    }
}

<5>在MainActivity中初始化，添加数据

public class GridActivity extends AppCompatActivity {
    private GridView mGridView;
    private LayoutInflater mFlater;//
    private MyGridAdapter myGridAdapter;
    private List<Flower> mFlower;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_grid);
        mGridView = (GridView) findViewById(R.id.gridview);
        mFlater = getLayoutInflater();//用来找res/layout/下的xml构架布局文件，并且实例化；
        mFlower = new ArrayList<>();
        Flower mudan= new Flower("牡丹", R.mipmap.flower_mudan);
        Flower baihe = new Flower("百合", R.mipmap.flower_baihe);
        Flower juhua = new Flower("菊花", R.mipmap.flower3);
        Flower meigui = new Flower("玫瑰",R.mipmap.flower_mei);
        for (int i = 0; i < 20; i++) {
            mFlower.add(mudan);
            mFlower.add(baihe);
            mFlower.add(juhua);
            mFlower.add(meigui);
        }
        myGridAdapter = new MyGridAdapter(mFlater,mFlower);
        mGridView.setAdapter(myGridAdapter);

    }

最终效果

2、ExpandableListView

步骤同gridview和listview

要求搭建如下界面：分四个班级，班级可以点开，下属学生

通过案例说明不同点：
<1>在本次案例中，需要两个类：student类和clazz类

//student类中就是学生的属性，方法和构造器。clazz类中是班级的属性，方法和构造器。不同的是在，calzz中添加如下内容
    private List<Student> students;//学生的集合

    public List<Student> getStudents() {
        return students;
    }

    public void setStudents(List<Student> students) {
        this.students = students;
    }

<2>需要两个布局文件item_calzz和item_student

//clazz的布局文件，设置班级显示部分的布局
<?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="match_parent"
    android:orientation="horizontal"
    android:gravity="center_horizontal">

    <TextView
        android:id="@+id/clazz_name"
        android:layout_width="wrap_content"
        android:layout_height="50dp"//设置班级这一条数据的宽度
        android:layout_marginRight="10dp"与右边的间隔
        android:text="mingzi"/>

    <TextView
        android:id="@+id/clazz_num"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/clazz_students"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

//student布局文件，设置学生显示部分的数据布局
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_horizontal"
    android:background="#55ffff00">//设置学生数据区域的颜色
    <TextView
        android:id="@+id/student_name"
        android:layout_width="wrap_content"
        android:layout_height="30dp"
        android:layout_marginRight="10dp"/>
    <TextView
        android:id="@+id/student_sex"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginRight="10dp"/>
    <TextView
        android:id="@+id/student_num"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

<3>Adapter文件的不同

public class ExpandableAdapter extends BaseExpandableListAdapter {
//继承BaseExpandableListAdapter
    private ExpandableListView mExpandable;
    private List<Clazz> mClazz;
    private LayoutInflater mFlater;

    public ExpandableAdapter(List<Clazz> mClazz, LayoutInflater mFlater) {
        this.mClazz = mClazz;
        this.mFlater = mFlater;
    }

    @Override
    public int getGroupCount() {
        return mClazz.size();
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return mClazz.get(groupPosition).getStudents().size();
    }

    @Override
    public Object getGroup(int groupPosition) {
        return groupPosition;
    }

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        convertView = mFlater.inflate(R.layout.item_clazz,null);//对应班级的布局文件，对班级的属性进行操作
        TextView clazzName = (TextView) convertView.findViewById(R.id.clazz_name);
        TextView clazzNum = (TextView) convertView.findViewById(R.id.clazz_num);
        TextView clazzStudents = (TextView) convertView.findViewById(R.id.clazz_students);
        Clazz clazz = mClazz.get(groupPosition);
        clazzName.setText(clazz.getName());
        clazzNum.setText(clazz.getNum());
        clazzStudents.setText(""+clazz.getStudents().size());
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        convertView = mFlater.inflate(R.layout.item_student,null);//对应学生的布局文件，对学生的属性进行操作
        TextView studentName = (TextView) convertView.findViewById(R.id.student_name);
        TextView studentNum = (TextView) convertView.findViewById(R.id.student_num);
        TextView studentSex = (TextView) convertView.findViewById(R.id.student_sex);
        Clazz clazz = mClazz.get(groupPosition);
        List<Student> students = clazz.getStudents();
        Student student = students.get(childPosition);
        studentName.setText(student.getName());
        studentNum.setText(student.getNum());
        studentSex.setText(student.getSex());
        return convertView;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return false;
    }
}

<4>MainActivity

public class MainActivity extends AppCompatActivity {
    private ExpandableListView mExpandableList;
    private List<Clazz> clazzs;
    private LayoutInflater mFlater;
    private ExpandableAdapter mAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mExpandableList = (ExpandableListView) findViewById(R.id.expandable);
        initData();
        mFlater = getLayoutInflater();
        mAdapter = new ExpandableAdapter(clazzs, mFlater);
        mExpandableList.setAdapter(mAdapter);
    }

    private void initData() {
        clazzs = new ArrayList<>();
        Clazz clazz1 = new Clazz("一班", "201501");
        List<Student> stu1 = new ArrayList<>();
        stu1.add(new Student("张三", "男", "1"));
        stu1.add(new Student("李四", "男", "1"));
        stu1.add(new Student("王五", "女", "1"));
        clazz1.setStudents(stu1);
        Clazz clazz2 = new Clazz("二班", "201502");
        List<Student> stu2 = new ArrayList<>();
        stu2.add(new Student("张三", "男", "1"));
        stu2.add(new Student("李四", "男", "1"));
        stu2.add(new Student("王五", "女", "1"));
        clazz2.setStudents(stu2);
        Clazz clazz3 = new Clazz("三班", "201503");
        List<Student> stu3 = new ArrayList<>();
        stu3.add(new Student("张三", "男", "1"));
        stu3.add(new Student("李四", "男", "1"));
        stu3.add(new Student("王五", "女", "1"));
        clazz3.setStudents(stu3);
        Clazz clazz4 = new Clazz("四班", "201504");
        List<Student> stu4 = new ArrayList<>();
        stu4.add(new Student("张三", "男", "1"));
        stu4.add(new Student("李四", "男", "1"));
        stu4.add(new Student("王五", "女", "1"));
        clazz4.setStudents(stu4);
        clazzs.add(clazz1);
        clazzs.add(clazz2);
        clazzs.add(clazz3);
        clazzs.add(clazz4);
    }

3、AutoCompleteTextView

<1>新建module工程，然后写layout下的布局文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

 <AutoCompleteTextView
     android:id="@+id/autocomplete"
     android:layout_width="match_parent"
     android:layout_height="wrap_content" />

</RelativeLayout>

<2>MainActivity下初始化，加数据

public class MainActivity extends AppCompatActivity {
private AutoCompleteTextView mAutoeTextView;
    private ArrayAdapter<String> mAdapter;
    private String[] mData={"1515155","142546","152043",
            "135420","1420514","130256",};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mAutoeTextView = (AutoCompleteTextView)findViewById(R.id.autocomplete);
        mAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,mData);//这个simple_list_item_1是android中自带的，也可以自己写
        mAutoeTextView.setAdapter(mAdapter);
    }

4、Spinner

步骤同AutoCompleteTextView

//layout下的布局文件
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

<Spinner
    android:id="@+id/spinner"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"></Spinner>

</RelativeLayout>

public class MainActivity extends AppCompatActivity {
private Spinner mSpinner;
    private ArrayAdapter<String> mAdapter;
    private String[] mData={"1515155","142546","152043",
            "135420","1420514","130256",};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mSpinner = (Spinner) findViewById(R.id.spinner);
        mAdapter= new ArrayAdapter<String>(this,R.layout.item_spinner,mData);//这个item_spinner是自己写的，也可以用android自带的
        mSpinner.setAdapter(mAdapter);
    }