Advanced controls

Advanced control steps
3.1 obtaining data
3.2 create adapter

   Array adapter
   Simple adapter

3.3 binding adapter

Differences between high-level controls and low-level controls:

  **Use adapter or not**

1: Auto prompt box
1.AutoCompleteTextView

Case 1: automatic completion of data (array data)

Layout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

   <AutoCompleteTextView
       android:id="@+id/act_main_act1"
       android:layout_width="match_parent"
       android:layout_height="80dp" />
</LinearLayout>

2.java code:

Define global variables:
 //Arrayadapter < string > the type of array adapter is the same as that of array
    private String[] detal; 
    private ArrayAdapter<String> adapter1;         
    private AutoCompleteTextView act_main_act1;

//Initialization:
//Act > main > Item1: item resource
 protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    act_main_act1=findViewById(R.id.act_main_act1);
    // 3.1 obtaining data
   detal =new String[] { "Angry Birds", "Tom cat", "Soaked through", "Niu Niu", "A pug", "Dragon", "Roasted Duck",
            "Little elephant", "Mermaid", "a crafty and villainous person" };
    //3.2 create adapter
    adapter1=new ArrayAdapter<String>(this,R.layout.act_main_item1,detal);
   //3.3 binding adapter
    act_main_act1.setAdapter(adapter1);
 }

Item resources:

Create item resource: res - > layout - > New - > layout resource file

<?xml version="1.0" encoding="utf-8"?>
    <TextView
            xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:textColor="@color/red"
        >
    </TextView>

Design sketch:

2: Drop down list
1.Spinner

Case 1: display drop-down box

1.xml:

<Spinner
   android:id="@+id/sp_main_sp1"
   android:layout_width="match_parent"
   android:layout_height="match_parent">

2.java code:

 private List<Option> data2;
 private ArrayAdapter<Option> adapter2;
 private Spinner sp_main_sp1;

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sp_main_sp1=findViewById(R.id.sp_main_sp1);
        data2=loadData2();    //get data
        adapter2=new ArrayAdapter<Option>(this,R.layout.act_main_item1,data2);
        sp_main_sp1.setAdapter(adapter2);
        //Drop down box selected
        sp_main_sp1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int position, long id) {
                Option selectedItem = (Option) adapterView.getSelectedItem();
                Toast.makeText(MainActivity.this,selectedItem.getHtml(),Toast.LENGTH_LONG).show();
            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });
}

 //Specific methods of obtaining data
    private List<Option> loadData2() {
        List<Book> list = new BookDAO().list();
        List<Option> optionList=new ArrayList<>();
        for(Book book:list){
            optionList.add(new Option(book.getId()+"",book.getName()));
        }
        return optionList;
    }

Item resources:

<?xml version="1.0" encoding="utf-8"?>
    <TextView
            xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:textColor="@color/red"
        >
    </TextView>

Design sketch:

Case 2: the drop-down box shows the picture and name (simple adapter)
1.xml:

     <Spinner
       android:id="@+id/sp_main_sp2"
       android:layout_width="match_parent"
       android:layout_height="match_parent">
   </Spinner>

2.java code:

 //global variable
private List<Map<String,Object>> data3;
private SimpleAdapter adapter3;
private Spinner sp_main_sp2;

 //Initialization
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    act_main_act1=findViewById(R.id.act_main_act1);
    sp_main_sp2=findViewById(R.id.sp_main_sp2);
    data3=loadData3();  //Loading data
        //First parameter: context parameter
        //Second: List map data source
        //Third: Resources
        //Fourth: key of Map
        //Fifth: id set in item resource
        adapter3=new SimpleAdapter(this,data3,R.layout.sp_main_item2,new String[]{"image","name"},new int[]{R.id.img_main_item_iv1,R.id.tv_main_item_tv1});
        sp_main_sp2.setAdapter(adapter3);
}

    private List<Map<String,Object>> loadData3() {
            List<Book> list = new BookDAO().list();
            List<Map<String,Object>> mapList=new ArrayList<>();
            Map<String,Object> map=null;  //Declare map collection
            for(Book book:list){
                map=new HashMap<>();
                map.put("name",book.getName());
                map.put("image",book.getImage());
                mapList.add(map);
                Log.i("test","--------"+map.get("name")+"-------"+map.get("image"));    //Console output code
            }
            return mapList;
        }

Item resources:

<?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="60dp">

    <ImageView
        android:id="@+id/img_main_item_iv1"
        android:layout_width="60dp"
        android:layout_height="60dp" />

    <TextView
        android:id="@+id/tv_main_item_tv1"
        android:layout_width="match_parent"
        android:layout_height="match_parent" /> 
</LinearLayout>