1# 连接ServiceAbility
2
3
4如果ServiceAbility需要与PageAbility或其他应用的ServiceAbility进行交互，则须创建用于连接的Connection。ServiceAbility支持其他Ability通过[connectAbility()](../reference/apis-ability-kit/js-apis-ability-featureAbility.md#featureabilityconnectability7)方法与其进行连接。PageAbility的connectAbility()方法定义在[featureAbility](../reference/apis-ability-kit/js-apis-ability-featureAbility.md)中，ServiceAbility的connectAbility()方法定义在[particleAbility](../reference/apis-ability-kit/js-apis-ability-particleAbility.md)中。连接ServiceAbility的规则详见[组件启动规则](component-startup-rules-fa.md)章节。在使用connectAbility()处理回调时，需要传入目标Service的[Want](../reference/apis-ability-kit/js-apis-app-ability-want.md)与[IAbilityConnection](../reference/apis-ability-kit/js-apis-inner-ability-connectOptions.md)的实例。[IAbilityConnection](../reference/apis-ability-kit/js-apis-inner-ability-connectOptions.md)提供了以下方法供开发者实现。
5
6
7  **表1** IAbilityConnection接口说明
8
9| 接口名 | 描述 |
10| -------- | -------- |
11| onConnect() | 用于处理连接Service成功的回调。 |
12| onDisconnect() | 用来处理Service异常死亡的回调。 |
13| onFailed() | 用来处理连接Service失败的回调。 |
14
15
16PageAbility创建连接本地ServiceAbility回调实例的代码以及连接本地ServiceAbility的示例代码如下：
17
18```ts
19import featureAbility from '@ohos.ability.featureAbility';
20import common from '@ohos.app.ability.common';
21import Want from '@ohos.app.ability.Want';
22import promptAction from '@ohos.promptAction';
23import rpc from '@ohos.rpc';
24import hilog from '@ohos.hilog';
25```
26```ts
27const TAG: string = 'PageServiceAbility';
28const domain: number = 0xFF00;
29
30@Entry
31@Component
32struct PageServiceAbility {
33  //...
34  build() {
35    Column() {
36      //...
37      List({ initialIndex: 0 }) {
38        ListItem() {
39          Row() {
40            //...
41          }
42          .onClick(() => {
43            let option: common.ConnectOptions = {
44              onConnect: (element, proxy) => {
45                hilog.info(domain, TAG, `onConnectLocalService onConnectDone element:` + JSON.stringify(element));
46                if (proxy === null) {
47                  promptAction.showToast({
48                    message: 'connect_service_failed_toast'
49                  });
50                  return;
51                }
52                let data = rpc.MessageParcel.create();
53                let reply = rpc.MessageParcel.create();
54                let option = new rpc.MessageOption();
55                data.writeInterfaceToken('connect.test.token');
56                proxy.sendRequest(0, data, reply, option);
57                promptAction.showToast({
58                  message: 'connect_service_success_toast'
59                });
60              },
61              onDisconnect: (element) => {
62                hilog.info(domain, TAG, `onConnectLocalService onDisconnectDone element:${element}`);
63                promptAction.showToast({
64                  message: 'disconnect_service_success_toast'
65                });
66              },
67              onFailed: (code) => {
68                hilog.info(domain, TAG, `onConnectLocalService onFailed errCode:${code}`);
69                promptAction.showToast({
70                  message: 'connect_service_failed_toast'
71                });
72              }
73            };
74
75            let request: Want = {
76              bundleName: 'com.samples.famodelabilitydevelop',
77              abilityName: 'com.samples.famodelabilitydevelop.ServiceAbility',
78            };
79            let connId = featureAbility.connectAbility(request, option);
80            hilog.info(domain, TAG, `onConnectLocalService onFailed errCode:${connId}`);
81          })
82        }
83        //...
84      }
85      //...
86    }
87    //...
88  }
89}
90```
91
92
93同时，Service侧也需要在[onConnect()](../reference/apis-ability-kit/js-apis-inner-ability-connectOptions.md#onconnect)时返回[IRemoteObject](../reference/apis-ipc-kit/js-apis-rpc.md#iremoteobject)，从而定义与Service进行通信的接口。onConnect()需要返回一个IRemoteObject对象。系统提供了IRemoteObject的默认实现，开发者可以通过继承[rpc.RemoteObject](../reference/apis-ipc-kit/js-apis-rpc.md#remoteobject)来创建自定义的实现类。
94
95
96Service侧把自身的实例返回给调用侧的示例代码如下：
97
98```ts
99import type Want from '@ohos.app.ability.Want';
100import rpc from '@ohos.rpc';
101import hilog from '@ohos.hilog';
102
103const TAG: string = '[Sample_FAModelAbilityDevelop]';
104const domain: number = 0xFF00;
105
106class FirstServiceAbilityStub extends rpc.RemoteObject {
107  constructor(des: Object) {
108    if (typeof des === 'string') {
109      super(des);
110    } else {
111      return;
112    }
113  }
114
115  onRemoteRequest(code: number, data: rpc.MessageParcel, reply: rpc.MessageParcel, option: rpc.MessageOption): boolean {
116    hilog.info(domain, TAG, 'ServiceAbility onRemoteRequest called');
117    if (code === 1) {
118      let string = data.readString();
119      hilog.info(domain, TAG, `ServiceAbility string=${string}`);
120      let result = Array.from(string).sort().join('');
121      hilog.info(domain, TAG, `ServiceAbility result=${result}`);
122      reply.writeString(result);
123    } else {
124      hilog.info(domain, TAG, 'ServiceAbility unknown request code');
125    }
126    return true;
127  }
128}
129//...
130```
131