如何使用Android xml形状在圆圈内绘制圆圈？

Question

I'm trying to make a thumb for a seekbar for my app, and I want to have an inner circle surrounded by a different, larger (semi-transparent) outer circle. I'm trying to use layer-list , but I'm having issues. Below is my code...

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
<item>
    <shape
        android:shape="oval" >
        <solid android:color="#00f" />

        <size
            android:height="15dp"
            android:width="15dp" />
    </shape>
</item>

<item>
    <shape
        android:shape="oval" >
        <solid android:color="#f00" />

        <size
            android:height="10dp"
            android:width="10dp" />
    </shape>
</item>

</layer-list>

I would expect to see a small red circle on top of a larger blue circle, but all I'm seeing is the small red circle. Does anyone have any ideas?

Answer 1

The only way I've gotten this to work is to define a transparent stroke for the inner (ie, top) circle that's the difference between the size of the larger and smaller circle.

For example, this:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<!-- Larger blue circle in back -->
<item>
    <shape android:shape="oval">
        <solid android:color="#00f"/>
        <size
                android:width="15dp"
                android:height="15dp"/>
    </shape>
</item>
<!-- Smaller red circle in front -->
<item>
    <shape android:shape="oval">
        <!-- transparent stroke = larger_circle_size - smaller_circle_size -->
        <stroke android:color="@android:color/transparent"
                android:width="5dp"/>
        <solid android:color="#f00"/>
        <size
                android:width="10dp"
                android:height="10dp"/>
    </shape>
</item>
</layer-list>

...looks like this:

Answer 2

hope it will help. This is drawable *.xml

    <?xml version="1.0" encoding="utf-8"?>
    <layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

      <item>
          <shape android:shape="oval">
              <padding
                  android:bottom="1dp"
                  android:left="1dip"
                  android:right="1dp"
                  android:top="1dp" />

              <solid android:color="#000" />
          </shape>
      </item>
      <item>
          <shape android:shape="oval">
              <padding
                  android:bottom="1dp"
                  android:left="1dip"
                  android:right="1dp"
                  android:top="1dp" />

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

Answer 3

It's late but maybe helpful, you can use padding for center circle.

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
    <shape
        android:shape="oval">
        <solid
            android:color="#00fff"/>
        <padding
            android:bottom="30dp"
            android:left="30dp"
            android:right="30dp"
            android:top="30dp"/>
        <stroke
            android:width="1dp"
            android:color="@color/holo_red_light"/>
    </shape>
</item>
<item>
    <shape
        android:shape="oval">
        <solid
            android:color="#00666666"/>

        <size
            android:width="120dp"
            android:height="120dp"/>
        <stroke
            android:width="1dp"
            android:color="@color/holo_red_light"/>
    </shape>

</item>
</layer-list>

Answer 4

I managed to solve this by setting the width and height of the <item> in the <layer-list> . Probably not as best practise, but seem ok as was for background of icon in list view that had fixed dimensions.

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <!-- larger circle at the back -->
    <item android:height="54dp" android:width="54dp" android:gravity="center">
        <shape
               android:shape="oval">

            <solid
                android:color="#0000FF"/>

            <!-- thicker outer boarder -->
            <stroke
                android:width="2dp"
                android:color="#000000"/>
        </shape>
    </item>


    <!-- inner circle -->
    <item android:height="40dp" android:width="40dp" android:gravity="center">
        <shape
               android:shape="oval"  >
            <solid
                android:color="#00FF00"/>

            <stroke
                android:width="1dp"
                android:color="#000000"/>

        </shape>
    </item>
</layer-list>

Answer 5

I ended up here in search of drawing concentric circle found only answers with layer list approach so adding my answer with only using the shape , I hope it will help someone.

<shape android:shape="oval">
    <solid android:color="#FFF" />
    <size
        android:width="15dp"
        android:height="15dp" />
    <stroke
        android:width="6dp"
        android:color="#000" /> 
</shape>

And this is the outcome.

Answer 6

Hope below code snippet helps :)

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
        <!-- larger circle at the back -->
        <item>
            <shape xmlns:android="http://schemas.android.com/apk/res/android"
                   android:innerRadius="0dp"
                   android:shape="ring"
                   android:thicknessRatio="2"
                   android:useLevel="false" >
                  <solid android:color="#FFFFFF" />
                  <stroke
                      android:width="1dp"
                      android:color="#000000" /></shape>
        </item>

    <!-- inner circle -->
    <item  >
        <shape xmlns:android="http://schemas.android.com/apk/res/android"
               android:innerRadius="0dp"
               android:shape="ring"
               android:thicknessRatio="2.1"
               android:useLevel="false" >
            <solid android:color="#000000" />
            <stroke
                android:width="1dp"
                android:color="#FFFFFF" /></shape>
    </item>
</layer-list>

Answer 7

this is a short version of Sean Barbeau's answer

<stroke
    android:width="1dp"
    android:color="@color/white" />
<solid android:color="@color/dark_blue" />

<size
    android:width="14dp"
    android:height="14dp" />

Answer 8

Just you have to use Shap Attribute

xml code drawable

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval">
    <stroke android:width="2dp" android:color="#B91969"/>
    <size android:width="@dimen/dim_16dp" android:height="@dimen/dim_16dp" />
    <solid android:color="#0f0" />
</shape>

Output