[new feature] Radio: add shape prop & icon slot (#2651)

packages/radio/demo/index.vue

@@ -32,6 +32,21 @@
       </van-radio>
     </demo-block>
 
+    <demo-block :title="$t('customIcon')">
+      <van-radio
+        name="1"
+        value="1"
+        class="demo-radio-group"
+      >
+        {{ $t('customIcon') }}
+        <img
+          slot="icon"
+          slot-scope="props"
+          :src="props.checked ? icon.active : icon.normal"
+        >
+      </van-radio>
+    </demo-block>
+
     <demo-block :title="$t('withCell')">
       <van-radio-group v-model="radio3">
         <van-cell-group>
@@ -62,6 +77,7 @@ export default {
       radio: '单选框',
       text1: '未选中禁用',
       text2: '选中且禁用',
+      customIcon: '自定义图标',
       customColor: '自定义颜色',
       withCell: '与 Cell 组件一起使用'
     },
@@ -69,6 +85,7 @@ export default {
       radio: 'Radio',
       text1: 'Disabled',
       text2: 'Disabled and checked',
+      customIcon: 'Custom Icon',
       customColor: 'Custom Color',
       withCell: 'Inside a Cell'
     }
@@ -78,7 +95,11 @@ export default {
     return {
       radio1: '1',
       radio2: '2',
-      radio3: '1'
+      radio3: '1',
+      icon: {
+        normal: 'https://img.yzcdn.cn/public_files/2017/10/13/c547715be149dd3faa817e4a948b40c4.png',
+        active: 'https://img.yzcdn.cn/public_files/2017/10/13/793c77793db8641c4c325b7f25bf130d.png'
+      }
     };
   }
 };
@@ -93,5 +114,9 @@ export default {
       margin-bottom: 10px;
     }
   }
+
+  img {
+    height: 20px;
+  }
 }
 </style>