# Interface (FetchResult)

> **NOTE**
>
> The initial APIs of this module are supported since API version 10. Newly added APIs will be marked with a superscript to indicate their earliest API version.

FetchResult provides APIs to manage the file retrieval result.

## Modules to Import

```ts
import { photoAccessHelper } from '@kit.MediaLibraryKit';
```

## getCount

getCount(): number

Obtains the total number of files in the result set.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Return value**

| Type    | Description      |
| ------ | -------- |
| number | Returns the total number of files obtained.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  console.info('getCountDemo');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
  let fetchCount = fetchResult.getCount();
  console.info('fetchCount = ', fetchCount);
}
```

## isAfterLast

isAfterLast(): boolean

Checks whether the cursor is in the last row of the result set.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Return value**

| Type     | Description                                |
| ------- | ---------------------------------- |
| boolean | Returns **true** if the cursor is in the last row of the result set; returns **false** otherwise.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
  let fetchCount = fetchResult.getCount();
  console.info('count:' + fetchCount);
  let photoAsset: photoAccessHelper.PhotoAsset = await fetchResult.getLastObject();
  if (fetchResult.isAfterLast()) {
    console.info('photoAsset isAfterLast displayName = ', photoAsset.displayName);
  } else {
    console.info('photoAsset not isAfterLast.');
  }
}
```

## close

close(): void

Closes this FetchResult instance to invalidate it. After this instance is released, the APIs in this instance cannot be invoked.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  console.info('fetchResultCloseDemo');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  try {
    let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
    fetchResult.close();
    console.info('close succeed.');
  } catch (err) {
    console.error(`close fail. error: ${err.code}, ${err.message}`);
  }
}
```

## getFirstObject

getFirstObject(callback: AsyncCallback&lt;T&gt;): void

Obtains the first file asset in the result set. This API uses an asynchronous callback to return the result.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Parameters**

| Name  | Type                                         | Mandatory| Description                                       |
| -------- | --------------------------------------------- | ---- | ------------------------------------------- |
| callback | AsyncCallback&lt;T&gt; | Yes  | Callback used to return the first file asset obtained.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  console.info('getFirstObjectDemo');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
  fetchResult.getFirstObject((err, photoAsset) => {
    if (photoAsset !== undefined) {
      console.info('photoAsset displayName: ', photoAsset.displayName);
    } else {
      console.error(`photoAsset failed with err:${err.code}, ${err.message}`);
    }
  });
}
```

## getFirstObject

getFirstObject(): Promise&lt;T&gt;

Obtains the first file asset in the result set. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Return value**

| Type                                   | Description                      |
| --------------------------------------- | -------------------------- |
| Promise&lt;T&gt; | Promise used to return the first object in the result set.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  console.info('getFirstObjectDemo');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
  let photoAsset: photoAccessHelper.PhotoAsset = await fetchResult.getFirstObject();
  console.info('photoAsset displayName: ', photoAsset.displayName);
}
```

## getNextObject

getNextObject(callback: AsyncCallback&lt;T&gt;): void

Obtains the next file asset in the result set. This API uses an asynchronous callback to return the result.
Before using this API, you must use [isAfterLast()](#isafterlast) to check whether the current position is the end of the result set.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Parameters**

| Name   | Type                                         | Mandatory| Description                                     |
| --------- | --------------------------------------------- | ---- | ----------------------------------------- |
| callback | AsyncCallback&lt;T&gt; | Yes  | Callback used to return the next file asset obtained.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  console.info('getNextObjectDemo');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
  await fetchResult.getFirstObject();
  if (!fetchResult.isAfterLast()) {
    fetchResult.getNextObject((err, photoAsset) => {
      if (photoAsset !== undefined) {
        console.info('photoAsset displayName: ', photoAsset.displayName);
      } else {
        console.error(`photoAsset failed with err: ${err.code}, ${err.message}`);
      }
    });
  }
}
```

## getNextObject

getNextObject(): Promise&lt;T&gt;

Obtains the next file asset in the result set. This API uses a promise to return the result.
Before using this API, you must use [isAfterLast()](#isafterlast) to check whether the current position is the end of the result set.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Return value**

| Type                                   | Description             |
| --------------------------------------- | ----------------- |
| Promise&lt;T&gt; | Promise used to return the next object in the result set.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  console.info('getNextObjectDemo');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
  await fetchResult.getFirstObject();
  if (!fetchResult.isAfterLast()) {
    let photoAsset: photoAccessHelper.PhotoAsset = await fetchResult.getNextObject();
    console.info('photoAsset displayName: ', photoAsset.displayName);
  }
}
```

## getLastObject

getLastObject(callback: AsyncCallback&lt;T&gt;): void

Obtains the last file asset in the result set. This API uses an asynchronous callback to return the result.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Parameters**

| Name  | Type                                         | Mandatory| Description                       |
| -------- | --------------------------------------------- | ---- | --------------------------- |
| callback | AsyncCallback&lt;T&gt; | Yes  | Callback used to return the last file asset obtained.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  console.info('getLastObjectDemo');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
  fetchResult.getLastObject((err, photoAsset) => {
    if (photoAsset !== undefined) {
      console.info('photoAsset displayName: ', photoAsset.displayName);
    } else {
      console.error(`photoAsset failed with err: ${err.code}, ${err.message}`);
    }
  });
}
```

## getLastObject

getLastObject(): Promise&lt;T&gt;

Obtains the last file asset in the result set. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Return value**

| Type                                   | Description             |
| --------------------------------------- | ----------------- |
| Promise&lt;T&gt; | Promise used to return the last object in the result set.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  console.info('getLastObjectDemo');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
  let photoAsset: photoAccessHelper.PhotoAsset = await fetchResult.getLastObject();
  console.info('photoAsset displayName: ', photoAsset.displayName);
}
```

## getObjectByPosition

getObjectByPosition(index: number, callback: AsyncCallback&lt;T&gt;): void

Obtains a file asset with the specified index in the result set. This API uses an asynchronous callback to return the result.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Parameters**

| Name      | Type                                      | Mandatory  | Description                |
| -------- | ---------------------------------------- | ---- | ------------------ |
| index    | number                                   | Yes   | Index of the file asset to obtain. The value starts from **0**.    |
| callback | AsyncCallback&lt;T&gt; | Yes   | Callback used to return the file asset obtained.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  console.info('getObjectByPositionDemo');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
  fetchResult.getObjectByPosition(0, (err, photoAsset) => {
    if (photoAsset !== undefined) {
      console.info('photoAsset displayName: ', photoAsset.displayName);
    } else {
      console.error(`photoAsset failed with err: ${err.code}, ${err.message}`);
    }
  });
}
```

## getObjectByPosition

getObjectByPosition(index: number): Promise&lt;T&gt;

Obtains a file asset with the specified index in the result set. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Parameters**

| Name   | Type    | Mandatory  | Description            |
| ----- | ------ | ---- | -------------- |
| index | number | Yes   | Index of the file asset to obtain. The value starts from **0**.|

**Return value**

| Type                                   | Description             |
| --------------------------------------- | ----------------- |
| Promise&lt;T&gt; | Promise used to return the file asset obtained.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  console.info('getObjectByPositionDemo');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
  let photoAsset: photoAccessHelper.PhotoAsset = await fetchResult.getObjectByPosition(0);
  console.info('photoAsset displayName: ', photoAsset.displayName);
}
```

## getAllObjects

getAllObjects(callback: AsyncCallback&lt;Array&lt;T&gt;&gt;): void

Obtains all the file assets in the result set. This API uses an asynchronous callback to return the result.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Parameters**

| Name  | Type                                         | Mandatory| Description                                       |
| -------- | --------------------------------------------- | ---- | ------------------------------------------- |
| callback | AsyncCallback&lt;Array&lt;T&gt;&gt; | Yes  | Callback used to return an array of all file assets in the result set.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  console.info('getAllObjectDemo');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
  fetchResult.getAllObjects((err, photoAssetList) => {
    if (photoAssetList !== undefined) {
      console.info('photoAssetList length: ', photoAssetList.length);
    } else {
      console.error(`photoAssetList failed with err:${err.code}, ${err.message}`);
    }
  });
}
```

## getAllObjects

getAllObjects(): Promise&lt;Array&lt;T&gt;&gt;

Obtains all the file assets in the result set. This API uses a promise to return the result.

**Atomic service API**: This API can be used in atomic services since API version 20.

**System capability**: SystemCapability.FileManagement.PhotoAccessHelper.Core

**Return value**

| Type                                   | Description                      |
| --------------------------------------- | -------------------------- |
| Promise&lt;Array&lt;T&gt;&gt; | Promise used to return an array of all file assets.|

**Error codes**

For details about the error codes, see [Universal Error Codes](../errorcode-universal.md) and [File Management Error Codes](../apis-core-file-kit/errorcode-filemanagement.md).

| ID| Error Message|
| -------- | ---------------------------------------- |
| 13900020     | Invalid argument.         |
| 14000011       | System inner fail.         |

**Example**

For details about how to create a phAccessHelper instance, see the example provided in [photoAccessHelper.getPhotoAccessHelper](arkts-apis-photoAccessHelper-f.md#photoaccesshelpergetphotoaccesshelper).

```ts
import { dataSharePredicates } from '@kit.ArkData';

async function example(phAccessHelper: photoAccessHelper.PhotoAccessHelper) {
  console.info('getAllObjectDemo');
  let predicates: dataSharePredicates.DataSharePredicates = new dataSharePredicates.DataSharePredicates();
  let fetchOption: photoAccessHelper.FetchOptions = {
    fetchColumns: [],
    predicates: predicates
  };
  let fetchResult: photoAccessHelper.FetchResult<photoAccessHelper.PhotoAsset> = await phAccessHelper.getAssets(fetchOption);
  let photoAssetList: Array<photoAccessHelper.PhotoAsset> = await fetchResult.getAllObjects();
  console.info('photoAssetList length: ', photoAssetList.length);
}
```