1# Application Context 2 3>  **NOTE**<br/> 4> - The APIs of this module are no longer maintained since API version 7. You are advised to use the new APIs. 5> 6> - The initial APIs of this module are supported since API version 3. Newly added APIs will be marked with a superscript to indicate their earliest API version. 7 8 9## Modules to Import 10 11 12``` 13import app from '@system.app'; 14``` 15 16 17## app.getInfo 18 19getInfo(): AppResponse 20 21Obtains the declared information in the **config.json** file of an application. 22 23> **Note: ** [`@ohos.bundle`](js-apis-Bundle.md) is recommended from API version 7. 24 25**System capability**: SystemCapability.ArkUI.ArkUI.Lite 26 27**Return value** 28 29| Type| Description| 30| -------- | -------- | 31| [AppResponse](#appresponse) | Application response information.| 32 33**Example** 34 35 ``` 36 export default { 37 getInfo(){ 38 var info = app.getInfo(); 39 console.log(JSON.stringify(info)); 40 } 41 } 42 ``` 43 44## app.terminate 45 46terminate(): void 47 48Terminates the current ability. 49 50> **Note: ** [`@ohos.ability.featureAbility`](js-apis-featureAbility.md) is recommended from API version 7. 51 52**System capability**: SystemCapability.ArkUI.ArkUI.Lite 53 54**Example** 55 56 ``` 57 export default { 58 terminate(){ 59 app.terminate(); 60 }} 61 ``` 62## app.requestFullWindow 63 64requestFullWindow(options?: RequestFullWindowOptions): void 65 66Requests the application to run in full window. You can call this API when the FA runs in a non-full window, for example, semi-modal FA. This API is invalid for an application already in full-window mode. 67 68This is a system API and cannot be called by third-party applications. 69 70> **Note: ** [`@ohos.window`](js-apis-window.md) is recommended from API version 7. 71 72**System capability**: SystemCapability.ArkUI.ArkUI.Full 73 74**Parameters** 75| Name| Type| Mandatory| Description| 76| -------- | -------- | -------- | -------- | 77| options | [RequestFullWindowOptions](#requestfullwindowoptions) | No| Duration for transition from the non-full window to the full window, in milliseconds. By default, the value is in direct proportion to the distance between the non-full window and the full window.| 78 79**Example** 80 81 ``` 82 export default { 83 requestFullWindow(){ 84 app.requestFullWindow({ 85 duration: 200}); 86 } 87 } 88 ``` 89 90## app.setImageCacheCount<sup>7+</sup> 91 92setImageCacheCount(value: number): void 93 94Sets the maximum number of decoded images that can be cached in the memory to speed up the loading of images from the same sources. If the input parameter is not set, the default value **0** is used, indicating that images are not cached. The built-in Least Recently Used (LRU) policy is used for caching. If the maximum number is exceeded, the images that have not been updated for the longest time will be removed. You are advised to set the parameter based on the application memory requirements. If the number of images is too large, the memory usage may be too high. 95 96**System capability**: SystemCapability.ArkUI.ArkUI.Full 97 98**Parameters** 99| Name| Type| Mandatory| Description| 100| -------- | -------- | -------- | -------- | 101| value | number | No| Number of decoded images that are cached in the memory.| 102 103**Example** 104 105 ``` 106 // app.ets 107 import app from '@system.app'; 108 109 export default { 110 onCreate() { 111 app.setImageCacheCount(100) // Set the maximum number of decoded images that can be cached in the memory to 100. 112 console.info('Application onCreate') 113 }, 114 onDestroy() { 115 console.info('Application onDestroy') 116 }, 117 } 118 ``` 119 120## app.setImageRawDataCacheSize<sup>7+</sup> 121 122setImageRawDataCacheSize(value: number): void 123 124Sets the maximum size (in bytes) of the image data cached in the memory before decoding to speed up the loading of images from the same sources. If the input parameter is not set, the default value **0** is used, indicating that images are not cached. The LRU policy is used for caching. If the maximum size is exceeded, the images that have not been updated for the longest time will be removed. You are advised to set the parameter based on the application memory requirements. If the image cache is too large, the memory usage may be too high. 125 126**System capability**: SystemCapability.ArkUI.ArkUI.Full 127 128**Parameters** 129| Name| Type| Mandatory| Description| 130| -------- | -------- | -------- | -------- | 131| value | number | No| Size of the image data cached before decoding, in bytes.| 132 133**Example** 134 135 ``` 136 // app.ets 137 import app from '@system.app'; 138 139 export default { 140 onCreate() { 141 app.setImageRawDataCacheSize(104857600) 142 // Set the upper limit of the memory for caching image data before decoding to 100 MB. (100 x 1024 x 1024 B =104857600 B = 100 MB). 143 console.info('Application onCreate') 144 }, 145 onDestroy() { 146 console.info('Application onDestroy') 147 }, 148 } 149 ``` 150 151## app.setImageFileCacheSize<sup>7+</sup> 152 153setImageFileCacheSize(value: number): void 154 155Sets the maximum size of the image file cache (in bytes) to speed up the loading of images from the same sources, especially online image sources and thumbnails. If the input parameter is not set, the default value 100 MB is used. The LRU policy is used for caching. If the maximum size is exceeded, the images that have not been updated for the longest time will be removed. You are advised to set the parameter based on the application memory requirements. If the image cache is too large, the disk usage may be too high. 156 157**System capability**: SystemCapability.ArkUI.ArkUI.Full 158 159**Parameters** 160| Name| Type| Mandatory| Description| 161| -------- | -------- | -------- | -------- | 162| value | number | No| Size of the image file cache, in bytes.| 163 164**Example** 165 166 ``` 167 // app.ets 168 import app from '@system.app'; 169 170 export default { 171 onCreate() { 172 app.setImageFileCacheSize(209715200) 173 // Set the upper limit of the image file cache to 200 MB. (200 x 1024 x 1024 B= 209715200 B = 200 MB). 174 console.info('Application onCreate') 175 }, 176 onDestroy() { 177 console.info('Application onDestroy') 178 }, 179 } 180 ``` 181 182## AppResponse 183 184Defines the application response information. 185 186**System capability**: The items in the table below require different system capabilities. For details, see the table. 187 188| Name| Type| Mandatory| Description| 189| -------- | -------- | -------- |-------- | 190| appID<sup>6+</sup> | string | Yes| Bundle name of an application. It uniquely identifies the application.<br> **System capability**: SystemCapability.ArkUI.ArkUI.Full| 191| appName | string | Yes| Application name.<br> **System capability**: SystemCapability.ArkUI.ArkUI.Lite| 192| versionName | string | Yes| Application version name.<br> **System capability**: SystemCapability.ArkUI.ArkUI.Lite| 193| versionCode | number | Yes| Application version number.<br> **System capability**: SystemCapability.ArkUI.ArkUI.Lite| 194 195## ScreenOnVisibleOptions 196 197Defines the options of the visible interface on the screen. 198 199**System capability**: SystemCapability.ArkUI.ArkUI.Full 200 201| Name| Type| Mandatory| Description| 202| -------- | -------- | -------- | -------- | 203| visible | boolean | No| Whether to keep the application visible. The default value is **false**.| 204| success | () => void | No| Callback upon success.| 205| fail | (data: string, code: number) => void | No| Callback upon failure.| 206| complete | () => void | No| Called when the API call is complete.| 207 208## RequestFullWindowOptions 209 210Defines the options of the **RequestFullWindow** API. 211 212**System capability**: SystemCapability.ArkUI.ArkUI.Full 213 214| Name| Type| Mandatory| Description| 215| -------- | -------- | -------- | -------- | 216| duration | number | Yes| Number of animation options.| 217
