java - 安卓 : Get fragment's background color

Question

我试图通过 Activity 的 onCreate 方法从 fragment 的 XML 文件中获取 android:background 属性上设置的颜色。我使用了 getSolidColor() 和 getgetDrawingCacheBackgroundColor() 方法，但它们都返回与包含 fragment 的布局相对应的颜色值。

这是 Activity 代码部分:

private SeekBar seekBar;
private View fragmentOne;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    fragmentOne = findViewById(R.id.fragment1);
    seekBar = (SeekBar) findViewById(R.id.seekBar1);
    fragmentOne.getDrawingCacheBackgroundColor()

fragment 的 xml 文件，

<RelativeLayout
android:layout_height="match_parent"
android:layout_width="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
android:background="@color/colorAccent"
android:padding="5dp"/>

以及包含上述内容的 Activity_main xml 文件，以及其他 4 个 fragment 和一个搜索栏:

    <?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/black">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal">



        <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:layout_height="match_parent"
            android:layout_weight="2"
            android:orientation="vertical"
            android:padding="5dp"
            android:paddingBottom="@dimen/activity_vertical_margin"
            android:paddingLeft="@dimen/activity_horizontal_margin"
            android:paddingRight="@dimen/activity_horizontal_margin"
            android:paddingTop="@dimen/activity_vertical_margin"
            android:layout_marginBottom="20dp"
            android:layout_marginTop="20dp"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            tools:context="com.maryland.modernartui_nikos.MainActivity">





            <fragment
                android:id="@+id/fragment1"
                android:name="com.maryland.modernartui_nikos.FragmentOne"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="2"
                tools:layout="@layout/fragment_fragment_one" />

            <fragment

                android:id="@+id/fragment2"
                android:name="com.maryland.modernartui_nikos.FragmentTwo"
                android:layout_width="match_parent"
                android:layout_height="117dp"
                tools:layout="@layout/fragment_fragment_two" />


        </LinearLayout>


        <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:layout_height="match_parent"
            android:layout_weight="2"
            android:orientation="vertical"
            android:padding="2dp"
            android:paddingBottom="@dimen/activity_vertical_margin"
            android:paddingLeft="@dimen/activity_horizontal_margin"
            android:paddingRight="@dimen/activity_horizontal_margin"
            android:paddingTop="@dimen/activity_vertical_margin"
            android:showDividers="beginning|middle|end"
            android:layout_marginBottom="20dp"
            android:layout_marginTop="20dp"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            tools:context="com.maryland.modernartui_nikos.MainActivity">


            <fragment
                android:id="@+id/fragment3"
                android:name="com.maryland.modernartui_nikos.FragmentThree"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="2"
                tools:layout="@layout/fragment_fragment_three" />

            <fragment

                android:id="@+id/fragment4"
                     android:name="com.maryland.modernartui_nikos.FragmentFour"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="4"
                tools:layout="@layout/fragment_fragment_four" />


            <fragment

                android:id="@+id/fragment5"
                android:name="com.maryland.modernartui_nikos.FragmentFive"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="4"
                tools:layout="@layout/fragment_fragment_five" />


        </LinearLayout>



    </LinearLayout>

    <SeekBar
        android:id="@+id/seekBar1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:max="10"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true" />

该方法从 activity_main.xml 的 RelativeLayout 返回值，而不是从 fragment_one.xml 返回值。为什么？

Answer 1

找到了解决此问题的方法:

        ColorDrawable colorDrawableOne = (ColorDrawable) fragmentOne.getBackground();
    ColorDrawable colorDrawableTwo = (ColorDrawable) fragmentTwo.getBackground();
    ColorDrawable colorDrawableFour = (ColorDrawable) fragmentFour.getBackground();
    ColorDrawable colorDrawableFive = (ColorDrawable) fragmentFive.getBackground();

    final int colorOne = colorDrawableOne.getColor();
    final int colorTwo = colorDrawableTwo.getColor();
    final int colorFour = colorDrawableFour.getColor();
    final int colorFive=   colorDrawableFive.getColor();

必须调用 fragment 的 getBackground() 方法并将其存储到具有类型转换的 ColorDrawable 变量中。然后调用该对象的getColor()方法即可获取所需的颜色。