Half circle shape not work

问题

I try to create half circle background, in development IDE preview it works, but when I launch in emulator it doesn't work.

Here is my shape code :

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:height="50dp">
        <shape>
            <solid android:color="@color/colorAccentDark" />
        </shape>
    </item>
    <item android:top="-500dp" android:bottom="0dp" android:left="-100dp" android:right="-100dp">
        <shape>
            <corners android:radius="500dp" />
            <solid android:color="@color/colorAccentDark" />
        </shape>
    </item>
</layer-list>

And here is my layout code :

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

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/background_profile"
        android:layout_weight="1">

        <de.hdodenhof.circleimageview.CircleImageView
            android:id="@+id/profile_avatar"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:src="@drawable/ic_default_avatar"
            android:layout_centerHorizontal="true"
            android:layout_marginTop="50dp"/>

        <TextView
            android:id="@+id/profile_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerHorizontal="true"
            android:layout_below="@id/profile_avatar"
            android:layout_marginTop="20dp"
            android:textColor="@color/neutralWhite"
            android:textStyle="bold"
            android:textSize="18sp"
            android:text="Avatar Ang"/>

    </RelativeLayout>

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="4.04">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Hello Android!"/>

    </RelativeLayout>

</LinearLayout>

Maybe any other tweak to handle that? Thank you

回答1:

You cannot create a semicircle from xml. but you could achieve what you are looking for using a circle with appropriate margin & padding.

Your can use a circle shape .xml file. Create a fixed sized circle like this:

Example:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
       android:shape="oval"
       android:useLevel="false" >
   <solid android:color="#006AC5" />
   <size
    android:height="50dp"
    android:width="50dp" />
</shape>

回答2:

you can try this :

<?xml version="1.0" encoding="utf-8"?>
<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid android:color="#900021df"/>
    <size
        android:width="10dp"
        android:height="5dp"/>
    <corners
        android:bottomLeftRadius="20dp"
        android:bottomRightRadius="20dp"/>
</shape>

it gives this shape:

回答3:

curve_toolbar_bg.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="rectangle"/>
    </item>
    <item
        android:bottom="0dp"
        android:left="-100dp"
        android:right="-100dp"
        android:top="-80dp">
        <shape android:shape="oval">
            <solid android:color="@color/colorPrimary" />
        </shape>
    </item>
</layer-list>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="0dp"
        android:layout_height="?android:attr/actionBarSize"
        android:background="@drawable/rounded_corner"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.0">

    </android.support.v7.widget.Toolbar>
</android.support.constraint.ConstraintLayout>

回答4:

Try this. Remove the gradient part then it will look like same as you want.

<item>
    <shape xmlns:android="http://schemas.android.com/apk/res/android"
        android:shape="rectangle">
        <solid android:color="#00B0EA" />

    </shape>
</item>
<item
    android:bottom="400dp"
    android:left="-100dp"
    android:right="-100dp"
    android:top="-200dp">
    <shape xmlns:android="http://schemas.android.com/apk/res/android"
        android:shape="oval">
        <gradient
            android:angle="90"
            android:endColor="#65FFFFFF"
            android:startColor="#65FFFFFF" />
    </shape>
</item>
<item
    android:bottom="402dp"
    android:left="-100dp"

    android:right="-100dp"
    android:top="-280dp">
    <shape xmlns:android="http://schemas.android.com/apk/res/android"
        android:shape="oval">
        <solid android:color="#FFFFFF" />
    </shape>
</item>

回答5:

Backgournd.xml

---

<?xml version="1.0" encoding="utf-8"?>
<layer-list  xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape xmlns:android="http://schemas.android.com/apk/res/android"
            android:shape="rectangle">
            <solid android:color="#FFFFFF" />
        </shape>
    </item>
    <item
        android:bottom="410dp"
        android:left="-100dp"
        android:right="-100dp"
        android:top="-300dp">
        <shape xmlns:android="http://schemas.android.com/apk/res/android"
            android:shape="oval">

            <solid android:color="#7181A1" />
        </shape>
    </item>
</layer-list>

---

Output like

来源：https://stackoverflow.com/questions/40043351/half-circle-shape-not-work