ad-interstitial：补充详细API示例

docs/component/ad-interstitial.md

@@ -94,6 +94,47 @@ export default {
 </script>
 ```
 
+API示例
+
+```html
+<template>
+  <view>
+    <ad-interstitial ref="adInterstitial" adpid="1111111113" :loadnext="false" v-slot:default="{loading, error}" @load="onadload" @close="onadclose" @error="onaderror">
+      <view v-if="error">{{error}}</view>
+    </ad-interstitial>
+    <button type="primary" :disabled="isLoading" :loading="isLoading" @click="showAd">显示广告</button>
+  </view>
+</template>
+
+<script>
+export default {
+  data() {
+    return {
+      isLoading: false
+    }
+  },
+  methods: {
+    showAd() {
+      this.isLoading = true;
+      this.$refs.adInterstitial.show();
+    },
+    onadload(e) {
+      this.isLoading = false;
+      console.log('广告数据加载成功');
+    },
+    onadclose(e) {
+      // 用户点击了关闭广告
+      console.log("onadclose",e);
+    },
+    onaderror(e) {
+      // 广告加载失败
+      console.log("onaderror: ", e.detail);
+    }
+  }
+}
+</script>
+```
+
 **注意**
 
 - 微信小程序插屏广告触发频率限制：