Android app development notes-drop-down list (Spinner)

Drag the icon on the panel to the interface, and add the following code in res/strings. xml:

<String name = "spinner_prompt"> Blood type </string>

<String-array name = "bloods">

<Item> Boold Types A </item>

<Item> Boold Types B </item>

<Item> Boold Types O </item>

<Item> Boold Types AB </item>

</String-array>

First, add the description text of the List header;

The second item is the content of each item in the list;

Finally, modify related items in Properties, such:

 

 

 

 

 

 

The activity_main.xml list is as follows:

<Spinner

Android: id = "@ + id/spin01"

Android: layout_width = "wrap_content"

Android: layout_height = "wrap_content"

Android: layout_alignRight = "@ + id/btnOk"

Android: layout_below = "@ + id/radioGroup01"

Android: layout_marginTop = "22dp"

Android: entries = "@ array/bloods"

Android: prompt = "@ string/spinner_prompt"/>

 

Then, we start encoding.

The related code is as follows:

[Java]
// Spinner
M_adapterView = ArrayAdapter. createFromResource (
This, R. array. bloods, android. R. layout. simple_spinner_dropdown_item );

M_adapterView.setDropDownViewResource (
Android. R. layout. simple_spinner_dropdown_item );

M_spinner = (Spinner) findViewById (R. id. spin01 );
M_spinner.setAdapter (m_adapterView );
M_spinner.setOnItemSelectedListener (this );

// Spinner
M_adapterView = ArrayAdapter. createFromResource (
This, R. array. bloods, android. R. layout. simple_spinner_dropdown_item );

M_adapterView.setDropDownViewResource (
Android. R. layout. simple_spinner_dropdown_item );

M_spinner = (Spinner) findViewById (R. id. spin01 );
M_spinner.setAdapter (m_adapterView );
M_spinner.setOnItemSelectedListener (this );
 

The statement is as follows:

ArrayAdapter <CharSequence> m_adapterView;

Spinnerm_spinner;

 

CharSequence must be used in the wildcard of ArrayAdapter.

 

You can use either of the following code to obtain the selected string:

1. Read direct resource files

This. getResources (). getStringArray (R. array. bloods) [arg2]

2. Read the selected item

M_spinner.getSelectedItem (). toString ()

 

We recommend 2nd methods.

 

 

The effect is as follows: