使用RCTAsyncLocalStorage + getAllKeys

Question

我正在尝试在iOS本机代码上获取AsyncStorage。所以这是我的代码

- (void)jsonFromLocalRNStrogeForKey:(NSString *)key completion:(void (^)(NSDictionary * _Nullable, NSError * _Nullable))completion {
    RCTResponseSenderBlock rnCompletion = ^(NSArray *response) {

        NSString *jsonAsString;

        if (response.count > 1) {
            NSArray *response1 = response[1];
            if (response1.count > 0) {
                NSArray *response2 = response1[0];
                if (response2.count > 1) {
                    jsonAsString = response2[1];
                }
            }
        }

        @try {
            NSData *jsonAsData = [jsonAsString dataUsingEncoding:NSUTF8StringEncoding];

            NSError *error;

            NSDictionary *json = [
              NSJSONSerialization
              JSONObjectWithData:jsonAsData
              options:NSJSONReadingMutableContainers
              error:&error
            ];

            completion(json, error);
        }
        @catch (NSException *exception) {
            NSLog(@"error: %@", exception.reason);

            NSMutableDictionary * info = [NSMutableDictionary dictionary];
            [info setValue:exception.name forKey:@"ExceptionName"];
            [info setValue:exception.reason forKey:@"ExceptionReason"];
            [info setValue:exception.callStackReturnAddresses forKey:@"ExceptionCallStackReturnAddresses"];
            [info setValue:exception.callStackSymbols forKey:@"ExceptionCallStackSymbols"];
            [info setValue:exception.userInfo forKey:@"ExceptionUserInfo"];

            NSError *error = [[NSError alloc] initWithDomain:@"" code:1 userInfo:info];

            completion(nil, error);
        }
    };

    // RCTAsyncLocalStorage *storage = [RCTAsyncLocalStorage new];
    RCTAsyncLocalStorage *storage = [[RCTAsyncLocalStorage alloc] init];

    dispatch_async(storage.methodQueue, ^{
        @try {
            // [storage performSelector:@selector(multiGet:callback:) withObject:@[key] withObject:rnCompletion];
            [storage performSelector:@selector(getAllKeys:callback:) withObject:rnCompletion];
        }
        @catch (NSException *exception) {
            NSLog(@"error: %@", exception.reason);
        }
    });
}

当我试图得到我的一把钥匙(multiGet)

[self jsonFromLocalRNStrogeForKey:@"session" completion:^(NSDictionary* data,NSError* error) {
    if (data) {
        NSString * name = [data valueForKeyPath: @"token"];
        if (![name isKindOfClass:[NSNull class]]) {
            [self reportIncomingCallFrom:name withUUID:callInvite.uuid];
        }
    } else {
        NSLog(@"error: JSON Parsing Error: %@",error.localizedFailureReason);
    }
}];

我总是变得空虚

当我试图获取所有密钥(...@selector(getAllKeys:...)以查看我的AsyncStorage中有什么我得到了异常

@"NSInvalidArgumentException" - reason: @"-[RCTAsyncLocalStorage getAllKeys:callback:]: unrecognized selector sent to instance 0x1085512c0"

RN在RCTAsyncLocalStorage.m中有RCT_EXPORT_METHOD(getAllKeys:(RCTResponseSenderBlock)callback);但在RCTAsyncLocalStorage.h (void)getAllKeys:(RCTResponseSenderBlock)callback它不存在，甚至添加它不起作用（https://github.com/facebook/react-native/blob/master/React/Modules/RCTAsyncLocalStorage.h）。

---

"react-native": "^0.48.4",

How can I return NSJsonSerialization

Answer 1

首先，

RN在RCTAsyncLocalStorage.m中有RCT_EXPORT_METHOD（getAllKeys：（RCTResponseSenderBlock）回调）;但在RCTAsyncLocalStorage.h（void）getAllKeys：（RCTResponseSenderBlock）回调它不存在

在Objective-C中，即使未使用performSelector:withObject:在头文件中声明方法，也可以调用方法。

直接调用此方法（无需首先检查目标respondsToSelector:）是不好的做法，因为内部方法声明可能会更改。

其次，这条线是不正确的：

[storage performSelector:@selector(getAllKeys:callback:) withObject:rnCompletion];

在这里，你说getAllKeys::有两个参数，但是实现只声明了一个。

因此，提取所有键的正确方法如下：

dispatch_async(storage.methodQueue, ^{

    if([storage respondsToSelector:@selector(getAllKeys:)]){
        [storage performSelector:@selector(getAllKeys:) withObject:[^(NSArray* response){
            NSLog(@"Contents: %@",response);
        } copy]];
    }else{
        NSLog(@"storage does not respond to selector `getAllKeys:`");
    }

});