Fix format issue

Change-Id: I78d41e31ec2af9a108aef76fcd084b248254e46e
Signed-off-by: Nxujie <xujie223@huawei.com>

zh-cn/application-dev/connectivity/net-mdns.md

@@ -32,9 +32,9 @@ MDNS管理的典型场景有：
 | ohos.net.mdns.DiscoveryService | on(type: 'discoveryStop', callback: Callback<{serviceInfo: LocalServiceInfo, errorCode?: MdnsError}>): void | 订阅停止监听mDNS服务的通知。 |
 | ohos.net.mdns.DiscoveryService | off(type: 'discoveryStop', callback?: Callback<{ serviceInfo: LocalServiceInfo, errorCode?: MdnsError }>): void | 取消停止监听mDNS服务的通知。 |
 | ohos.net.mdns.DiscoveryService | on(type: 'serviceFound', callback: Callback\<LocalServiceInfo>): void | 订阅发现mDNS服务的通知。 |
-| ohos.net.mdns.DiscoveryService | off(type: 'serviceFound', callback?: Callback<LocalServiceInfo>): void | 取消发现mDNS服务的通知。 |
+| ohos.net.mdns.DiscoveryService | off(type: 'serviceFound', callback?: Callback\<LocalServiceInfo>): void | 取消发现mDNS服务的通知。 |
 | ohos.net.mdns.DiscoveryService | on(type: 'serviceLost', callback: Callback\<LocalServiceInfo>): void | 订阅移除mDNS服务的通知。 |
-| ohos.net.mdns.DiscoveryService | off(type: 'serviceLost', callback?: Callback<LocalServiceInfo>): void | 取消移除mDNS服务的通知。 |
+| ohos.net.mdns.DiscoveryService | off(type: 'serviceLost', callback?: Callback\<LocalServiceInfo>): void | 取消移除mDNS服务的通知。 |
 
 ## 管理本地服务
 
@@ -158,4 +158,4 @@ discoveryService.off('serviceFound', (data) => {
 discoveryService.off('serviceLost', (data) => {
   console.log(JSON.stringify(data));
 });
-```
+```
\ No newline at end of file

zh-cn/application-dev/reference/apis/js-apis-net-mdns.md

@@ -852,7 +852,7 @@ discoveryService.stopSearchingMDNS();
 
 ### off('serviceFound')<sup>10+</sup>
 
-off(type: 'serviceFound', callback?: Callback<LocalServiceInfo>): void
+off(type: 'serviceFound', callback?: Callback\<LocalServiceInfo>): void
 
 取消订阅发现mDNS服务的通知。
 
@@ -918,7 +918,7 @@ discoveryService.stopSearchingMDNS();
 
 ### off('serviceLost')<sup>10+</sup>
 
-off(type: 'serviceLost', callback?: Callback<LocalServiceInfo>): void
+off(type: 'serviceLost', callback?: Callback\<LocalServiceInfo>): void
 
 取消订阅移除mDNS服务的通知。