[Android] 更改Spinner(下拉式選單)字體樣式

下拉式選單的選單樣式

Step1 在activity_main.xml檔案中新增Spinner標籤

	<Spinner
	android:id="@+id/spinner"
	android:layout_width="300dp"
	android:layout_height="wrap_content"
	android:gravity="center"
	android:layoutMode="clipBounds"
	app:layout_constraintLeft_toLeftOf="parent"
	app:layout_constraintRight_toRightOf="parent"
	app:layout_constraintTop_toTopOf="parent"
	android:layout_marginTop="16dp"></Spinner>

view raw activity_main.xml hosted with ❤ by GitHub

Step2 在layout中新增myspinner.xml

在檔案中設定下拉式選單的TextView樣式 (文字顏色、大小等)

	<TextView xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="match_parent"
	android:layout_height="wrap_content"
	android:layout_marginBottom="5dp"
	android:textColor="@color/colorAccent"
	android:textSize="16sp"
	android:paddingTop="10dp"
	android:paddingBottom="10dp"
	android:paddingLeft="16dp"
	android:gravity="center_vertical"/>

view raw myspinner.xml hosted with ❤ by GitHub

註：增加padding可以讓選單的間距變寬

Step3 在MainActivity.java檔案中設定Spinner

宣告spinner，並建立string array放入下拉選單中選項內容

	spinneer = (Spinner) findViewById(R.id.spinner);
	final String[] item = {"A", "B", "C", "D", "E", "F"};

view raw MainActivity.java hosted with ❤ by GitHub

建立ArrayAdapter，放入我們想要顯示樣式及選項內容

	ArrayAdapter<String> itemlist = new ArrayAdapter<>(this,R.layout.myspinner,
	item);

view raw MainActivity.java hosted with ❤ by GitHub

如果是想要用Android內建的樣式，只要把R.layout.myspinner改回android.R.layout.simple_list_item_1就可以了

	ArrayAdapter<String> itemlist = new ArrayAdapter<>(this,android.R.layout.simple_list_item_1,
	item);

view raw MainActivity.java hosted with ❤ by GitHub

最後設定Spinner的Adapter為剛剛我們建立的ArrayAdapter

完整的程式碼：

	private Spinner spinneer;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_main);
	spinneer = (Spinner) findViewById(R.id.spinner);
	final String[] item = {"A", "B", "C", "D", "E", "F"};
	ArrayAdapter<String> itemlist = new ArrayAdapter<>(this,R.layout.myspinner,
	item);
	spinneer.setAdapter(itemlist);
	}

view raw MainActivity.java hosted with ❤ by GitHub

執行結果：