1# @ohos.app.ability.errorManager (ErrorManager) 2 3The **ErrorManager** module provides APIs for registering and deregistering error observers. 4 5> **NOTE** 6> 7> The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version. 8 9## Modules to Import 10``` 11import errorManager from '@ohos.app.ability.errorManager' 12``` 13 14## ErrorManager.on 15 16on(type: 'error', observer: ErrorObserver): number; 17 18Registers an error observer. 19 20**System capability**: SystemCapability.Ability.AbilityRuntime.Core 21 22**Parameters** 23 24| Name| Type| Mandatory| Description| 25| -------- | -------- | -------- | -------- | 26| type | string | Yes| Type of the API to call.| 27| observer | [ErrorObserver](./js-apis-inner-application-errorObserver.md) | Yes| Digital code of the observer.| 28 29**Example** 30 31```js 32let observer = { 33 onUnhandledException(errorMsg) { 34 console.log('onUnhandledException, errorMsg: ', errorMsg) 35 } 36}; 37try { 38 errorManager.on('error', observer); 39} catch (paramError) { 40 console.log('error: ' + paramError.code + ', ' + paramError.message); 41} 42``` 43 44## ErrorManager.off 45 46off(type: 'error', observerId: number, callback: AsyncCallback\<void>): void; 47 48Deregisters an error observer. This API uses an asynchronous callback to return the result. 49 50**System capability**: SystemCapability.Ability.AbilityRuntime.Core 51 52**Parameters** 53 54| Name| Type| Mandatory| Description| 55| -------- | -------- | -------- | -------- | 56| type | string | Yes| Type of the API to call.| 57| observerId | number | Yes| Digital code of the observer.| 58| callback | AsyncCallback\<void> | Yes| Callback used to return the result.| 59 60**Example** 61 62```js 63let observerId = 100; 64 65function unregisterErrorObserverCallback(err) { 66 if (err) { 67 console.log('------------ unregisterErrorObserverCallback ------------', err); 68 } 69} 70try { 71 errorManager.off('error', observerId, unregisterErrorObserverCallback); 72} catch (paramError) { 73 console.log('error: ' + paramError.code + ', ' + paramError.message); 74} 75``` 76 77## ErrorManager.off 78 79off(type: 'error', observerId: number): Promise\<void>; 80 81Deregisters an error observer. This API uses a promise to return the result. 82 83**System capability**: SystemCapability.Ability.AbilityRuntime.Core 84 85**Parameters** 86 87| Name| Type| Mandatory| Description| 88| -------- | -------- | -------- | -------- | 89| type | string | Yes| Type of the API to call.| 90| observerId | number | Yes| Digital code of the observer.| 91 92**Return value** 93 94| Type| Description| 95| -------- | -------- | 96| Promise\<void> | Promise used to return the result.| 97 98**Example** 99 100```js 101let observerId = 100; 102try { 103 errorManager.off('error', observerId) 104 .then((data) => { 105 console.log('----------- unregisterErrorObserver success ----------', data); 106 }) 107 .catch((err) => { 108 console.log('----------- unregisterErrorObserver fail ----------', err); 109 }); 110} catch (paramError) { 111 console.log('error: ' + paramError.code + ', ' + paramError.message); 112} 113 114``` 115