正文
React-native之持久化保存----AsyncStorage
提示：扫一扫查出行【扫一扫了解最新限行尾号】
复制提示
AsyncStorage
AsyncStorage是一个简单的，未加密的，异步的，持久化，关键值存储系统，是全局的。
iOS中存储类似于NSUserDefault,存储问plist文件存放在设备中。
Android中存储会在RocksDB 或者 SQLite 中，哪个可用就用哪个...
存数据
/**
* Sets value for key and calls callback on completion, along with an Error if there is any
*/
setItem( key: string, value: string, callback?: ( error?: Error ) => void ): Promise<string>
e.g
try {
AsyncStorage.setItem(
'key',
'I like to save it.',
(error)=>{
console.log(error);
});
} catch (error) {
// Error saving data
console.log(error);
}
取数据
/**
* Fetches key and passes the result to callback, along with an Error if there is any.
*/
getItem( key: string, callback?: ( error?: Error, result?: string ) => void ): Promise<string>
e.g
try {
AsyncStorage.getItem(
'key',
(error,result)=>{
if (error){
console.log(error);
}
else
{
console.log(result);
}
});
}
catch (error){
console.log(error);
}
删数据
removeItem( key: string, callback?: ( error?: Error ) => void ): Promise<string>
合并数据
/**
* Merges existing value with input value, assuming they are stringified json. Returns a Promise object.
* Not supported by all native implementation
*/
mergeItem( key: string, value: string, callback?: ( error?: Error ) => void ): Promise<string>
清除数据
/**
* Erases all AsyncStorage for all clients, libraries, etc. You probably don't want to call this.
* Use removeItem or multiRemove to clear only your own keys instead.
*/
clear( callback?: ( error?: Error ) => void ): Promise<string>
获得所有的key
/**
* Gets all keys known to the app, for all callers, libraries, etc
*/
getAllKeys( callback?: ( error?: Error, keys?: string[] ) => void ): Promise<string>
通过传入的多个key来获取匹配的value
/**
* multiGet invokes callback with an array of key-value pair arrays that matches the input format of multiSet
*/
multiGet( keys: string[], callback?: ( errors?: Error[], result?: string[][] ) => void ): Promise<string>
通过传入多个键值对一起缓存
/**
* multiSet and multiMerge take arrays of key-value array pairs that match the output of multiGet,
*
* multiSet([['k1', 'val1'], ['k2', 'val2']], cb);
*/
multiSet( keyValuePairs: string[][], callback?: ( errors?: Error[] ) => void ): Promise<string>
删除所有的与key匹配的缓存数据
/**
* Delete all the keys in the keys array.
*/
multiRemove( keys: string[], callback?: ( errors?: Error[] ) => void ): Promise<string>
合并keyvalues
/**
* Merges existing values with input values, assuming they are stringified json.
* Returns a Promise object.
*
* Not supported by all native implementations.
*/
multiMerge( keyValuePairs: string[][], callback?: ( errors?: Error[] ) => void ): Promise<string>
