android 設置自定義主題及切換方案

1. 定義屬性
2. 在不同樣式中聲明屬性值
3. 在佈局中使用屬性
4. 再在代碼中進行切換
   

1. 在attr.xml文件中定義屬性顏色、字體大小等

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <attr name="tvColor1" format="color" />
    <attr name="bgNormalColor" format="color" />
    <attr name="tvSize1" format="dimension" />
</resources>

2. 在style.xml中設置屬性值

<resources>

    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <item name="tvColor1">#333333</item>
        <item name="tvSize1">12sp</item>
        <item name="bgNormalColor">#fefefe</item>
    </style>

    <style name="AppTheme2" parent="Theme.AppCompat.DayNight">
        <item name="colorPrimary">#ff0000</item>
        <item name="colorPrimaryDark">#ff00ff</item>
        <item name="colorAccent">#ffff00</item>
        <item name="tvColor1">#ff0000</item>
        <item name="tvSize1">28sp</item>
        <item name="bgNormalColor">#666</item>
    </style>

</resources>

3. 在佈局中使用

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:layout_height="match_parent"
    android:background="?attr/bgNormalColor"
    tools:context=".MainActivity">


    <EditText
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        android:layout_width="100dp"
        android:layout_height="wrap_content" />

    <Button
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_width="wrap_content"
        android:text="change Theme"
        android:textColor="?attr/tvColor1"
        android:textSize="?attr/tvSize1"

        android:onClick="changeTheme"
        android:layout_height="wrap_content" />
</androidx.constraintlayout.widget.ConstraintLayout>

4.在MainActivity中切換

public class MainActivity extends AppCompatActivity {
    private int themeType;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        themeType = getSharedPreferences("theme", MODE_PRIVATE).getInt("themeType", 0);
        if (themeType == 0) {
            setTheme(R.style.AppTheme);
        } else {
            setTheme(R.style.AppTheme2);
        }
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void changeTheme(View view) {
        themeType = themeType == 0 ? 1 : 0;
        getSharedPreferences("theme", MODE_PRIVATE).edit().putInt("themeType", themeType).commit();
        recreate();
        //會丟失當前頁面的狀態，需要保持的數據做持久化保持
    }
}