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);    }