harmony 鸿蒙@system.storage (Data Storage)

2022-08-09
浏览 (843)

@system.storage (Data Storage)

NOTE

The APIs of this module are no longer maintained since API version 6, and you are advised to use @ohos.data.storage. From API version 9, you are advised to use @ohos.data.preferences.

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.

The APIs of this module can be used only in the FA model.

Modules to Import

import storage from '@system.storage';

storage.get

get(options: GetStorageOptions): void

Reads the value stored in the cache based on the specified key.

System capability: SystemCapability.DistributedDataManager.Preferences.Core.Lite

Parameters

Name	Type	Mandatory	Description
options	GetStorageOptions	Yes	API configuration.

Example

export default {    
  storageGet() {        
    storage.get({            
      key: 'storage_key',            
      success: function(data) {                
        console.log('call storage.get success: ' + data);            
      },            
      fail: function(data, code) {                
        console.log('call storage.get fail, code: ' + code + ', data: ' + data);            
      },            
      complete: function() {                
        console.log('call complete');            
      },
    });    
  }
}

storage.set

set(options: SetStorageOptions): void

Sets the value in the cache based on the specified key.

System capability: SystemCapability.DistributedDataManager.Preferences.Core.Lite

Parameters

Name	Type	Mandatory	Description
options	SetStorageOptions	Yes	API configuration.

Example

export default {    
  storageSet() {        
    storage.set({            
      key: 'storage_key',            
      value: 'storage value',            
      success: function() {                
        console.log('call storage.set success.');            
      },            
      fail: function(data, code) {                
        console.log('call storage.set fail, code: ' + code + ', data: ' + data);            
      },        
    });    
  }
}

storage.clear

clear(options?: ClearStorageOptions): void

Clears the key-value pairs from the cache.

System capability: SystemCapability.DistributedDataManager.Preferences.Core.Lite

Parameters

Name	Type	Mandatory	Description
options	ClearStorageOptions	No	API configuration.

Example

export default {    
  storageClear() {        
    storage.clear({            
      success: function() {                
        console.log('call storage.clear success.');            
      },            
      fail: function(data, code) {                
        console.log('call storage.clear fail, code: ' + code + ', data: ' + data);            
      },        
    });    
  }
}

storage.delete

delete(options: DeleteStorageOptions): void

Deletes the key-value pair based on the specified key.

System capability: SystemCapability.DistributedDataManager.Preferences.Core.Lite

Parameters

Name	Type	Mandatory	Description
options	DeleteStorageOptions	Yes	API configuration.

Example

export default {    
  storageDelete() {        
    storage.delete({            
      key: 'Storage1',            
      success: function() {                
        console.log('call storage.delete success.');            
      },            
      fail: function(data, code) {                
        console.log('call storage.delete fail, code: ' + code + ', data: ' + data);            
      },        
    });    
  }
}

GetStorageOptions

System capability: SystemCapability.DistributedDataManager.Preferences.Core.Lite

Name	Type	Mandatory	Description
key	string	Yes	Key of the target data.
default	string	No	Default value returned when the specified key does not exist.
success	(data: any) => void	No	Called to return the result when storage.get() is called successfully. data is the value indexed by the specified key.
fail	(data: string, code: number) => void	No	Called to return the result when storage.get() fails to be called. data is the error information, and code indicates the error code.
complete	() => void	No	Called when storage.get() is complete.

SetStorageOptions

System capability: SystemCapability.DistributedDataManager.Preferences.Core.Lite

Name	Type	Mandatory	Description
key	string	Yes	Key of the data to set.
value	string	Yes	New value to set. The length must be less than 128 bytes.
success	() => void	No	Called when storage.set() is called successfully.
fail	(data: string, code: number) => void	No	Called to return the result when storage.set() fails to be called. data is the error information, and code indicates the error code.
complete	() => void	No	Called when storage.set() is complete.

ClearStorageOptions

System capability: SystemCapability.DistributedDataManager.Preferences.Core.Lite

Name	Type	Mandatory	Description
success	() => void	No	Called when storage.clear() is called successfully.
fail	(data: string, code: number) => void	No	Called to return the result when storage.clear() fails to be called. data is the error information, and code indicates the error code.
complete	() => void	No	Called when storage.clear() is complete.

DeleteStorageOptions

System capability: SystemCapability.DistributedDataManager.Preferences.Core.Lite

Name	Type	Mandatory	Description
key	string	Yes	Key of the data to delete.
success	() => void	No	Called when storage.delete() is called successfully.
fail	(data: string, code: number) => void	No	Called to return the result when storage.delete() fails to be called. data is the error information, and code indicates the error code.
complete	() => void	No	Called when storage.delete() is complete.