sharp 画三条边

要画出下面的效果：

[code]<RadioGroup
            android:layout_width="match_parent"
            android:layout_height="50dp"
            android:orientation="horizontal"
            android:weightSum="3">
            <RadioButton
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:background="@drawable/radiobutton_left_selector"
                android:button="@null"
                android:gravity="center"
                android:text="详情"
                android:textColor="@color/radiobutton_white_gray" />

            <RadioButton
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:checked="false"
                android:background="@drawable/radiobutton_center_selector"
                android:button="@null"
                android:gravity="center"
                android:text="评论"
                android:textColor="@color/radiobutton_white_gray" />

            <RadioButton
                android:checked="false"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:background="@drawable/radiobutton_right_selector"
                android:button="@null"
                android:gravity="center"
                android:text="赞(0)"
                android:textColor="@color/radiobutton_white_gray" />
  </RadioGroup>

res/drawable/radiobutton_left_selector.xml：

[code]<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_checked="true" android:state_enabled="true">
        <layer-list>
            <!-- 边框颜色值 -->
            <item>
                <shape android:shape="rectangle">
                    <solid android:color="@color/green" />
                    <corners android:bottomLeftRadius="5dp" android:bottomRightRadius="0dp" android:topLeftRadius="5dp" android:topRightRadius="0dp" />
                    <padding android:bottom="0dp" android:left="0dp" android:right="0dp" android:top="0dp" />
                    <stroke android:width="1dp" android:color="@color/green" />
                </shape>
            </item>
            <!-- 主体背景颜色值 -->
            <item android:bottom="0dp" android:left="1dp" android:right="1dp" android:top="1dp">
                <shape android:shape="rectangle">
                    <solid android:color="@color/green" />
                    <corners android:bottomLeftRadius="5dp" android:bottomRightRadius="0dp" android:topLeftRadius="5dp" android:topRightRadius="0dp" />
                    <padding android:bottom="0dp" android:left="0dp" android:right="0dp" android:top="0dp" />
                </shape>
            </item>
        </layer-list>
    </item>
    <item android:state_checked="false" android:state_enabled="true">
        <layer-list>
            <!-- 边框颜色值 -->
            <item>
                <shape android:shape="rectangle">
                    <solid android:color="@color/gray_F4F4F4" />
                    <corners android:bottomLeftRadius="5dp" android:bottomRightRadius="0dp" android:topLeftRadius="5dp" android:topRightRadius="0dp" />
                    <padding android:bottom="0dp" android:left="0dp" android:right="0dp" android:top="0dp" />
                    <stroke android:width="1dp" android:color="@color/gray_E2E2E2" />
                </shape>
            </item>
            <!-- 主体背景颜色值 -->
            <item android:bottom="1dp" android:left="1dp" android:right="0dp" android:top="1dp">
                <shape android:shape="rectangle">
                    <solid android:color="@color/gray_F4F4F4" />
                    <!-- 圆角 -->
                    <corners android:bottomLeftRadius="5dp" android:bottomRightRadius="0dp" android:topLeftRadius="5dp" android:topRightRadius="0dp" />
                    <padding android:bottom="0dp" android:left="0dp" android:right="0dp" android:top="0dp" />
                    <stroke android:width="0dp" android:color="@color/gray_E2E2E2" />
                </shape>
            </item>

        </layer-list>
    </item>
</selector>

res/drawable/radiobutton_center_selector.xml：

[code]<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_checked="true" android:state_enabled="true">
        <shape android:shape="rectangle">
            <solid android:color="@color/green" />

            <corners android:bottomLeftRadius="0dp" android:bottomRightRadius="0dp" android:topLeftRadius="0dp" android:topRightRadius="0dp" />

            <padding android:bottom="0dp" android:left="0dp" android:right="0dp" android:top="0dp" />

            <stroke android:width="1dp" android:color="@color/green" />
        </shape>
    </item>
    <item android:state_checked="false" android:state_enabled="true">
        <shape android:shape="rectangle">
            <solid android:color="@color/gray_F4F4F4" />

            <corners android:bottomLeftRadius="0dp" android:bottomRightRadius="0dp" android:topLeftRadius="0dp" android:topRightRadius="0dp" />

            <padding android:bottom="0dp" android:left="0dp" android:right="0dp" android:top="0dp" />

            <stroke android:width="1dp" android:color="@color/gray_E2E2E2" />
        </shape>
    </item>

</selector>

res/drawable/radiobutton_right_selector.xml：

[code]<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_checked="true" android:state_enabled="true">
        <layer-list>
            <!-- 边框颜色值 -->
            <item>
                <shape android:shape="rectangle">
                    <!--填充色-->
                    <solid android:color="@color/green" />
                    <!-- 圆角 -->
                    <corners android:bottomLeftRadius="0dp" android:bottomRightRadius="5dp" android:topLeftRadius="0dp" android:topRightRadius="5dp" />
                    <!--边距-->
                    <padding android:bottom="0dp" android:left="0dp" android:right="0dp" android:top="0dp" />
                    <!--边-->
                    <stroke android:width="1dp" android:color="@color/green" />
                </shape>
            </item>
            <!-- 主体背景颜色值 android:left="0dp" 表示不要画左边-->
            <item android:bottom="1dp" android:left="0dp" android:right="1dp" android:top="1dp">
                <shape android:shape="rectangle">
                    <solid android:color="@color/green" />
                    <corners android:bottomLeftRadius="0dp" android:bottomRightRadius="5dp" android:topLeftRadius="0dp" android:topRightRadius="5dp" />
                    <padding android:bottom="0dp" android:left="0dp" android:right="0dp" android:top="0dp" />
                    <stroke android:width="1dp" android:color="@color/green" />
                </shape>
            </item>
        </layer-list>

    </item>
    <item android:state_checked="false" android:state_enabled="true">
        <layer-list>
            <!-- 边框颜色值 -->
            <item>
                <shape android:shape="rectangle">
                    <solid android:color="@color/gray_F4F4F4" />
                    <corners android:bottomLeftRadius="0dp" android:bottomRightRadius="5dp" android:topLeftRadius="0dp" android:topRightRadius="5dp" />
                    <padding android:bottom="0dp" android:left="0dp" android:right="0dp" android:top="0dp" />
                    <stroke android:width="1dp" android:color="@color/gray_E2E2E2" />
                </shape>
            </item>
            <!-- 主体背景颜色值 -->
            <item android:bottom="1dp" android:left="0dp" android:right="1dp" android:top="1dp">
                <shape android:shape="rectangle">
                    <solid android:color="@color/gray_F4F4F4" />
                    <corners android:bottomLeftRadius="0dp" android:bottomRightRadius="5dp" android:topLeftRadius="0dp" android:topRightRadius="5dp" />
                    <padding android:bottom="0dp" android:left="0dp" android:right="0dp" android:top="0dp" />
                    <stroke android:width="0dp" android:color="@color/gray_E2E2E2" />
                </shape>
            </item>

        </layer-list>

    </item>

</selector>

radiobutton_left_selector 和radiobutton_right_selector 都只画了三条边。

res/drawable/color/radiobutton_white_gray.xml:

[code]<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_checked="true" android:state_enabled="true" android:color="@color/white"/>
    <item android:color="@color/textColor_gray"/>
</selector>