iOS-项目开发中，对后台返回数据为时候的处理,避免取值产生程序崩溃问题

Bertha 。 2023-10-18 20:53 17阅读 0赞

方法一：使用AFNetworking进行请求过滤设置：

((AFJSONResponseSerializer *)manager.responseSerializer).removesKeysWithNullValues = YES;

方法二：使用runtime来给类别增加属性

NSNull+Safe.m

#import <objc/runtime.h>
    #import <Foundation/Foundation.h>
    
    static NSString *dataKey = @"key";
    
    @interface NSNull ()
    
    @property (strong, nonatomic) NSMutableDictionary *data;
    
    @end
    
    
    @implementation NSNull (Safe)
    #pragma mark - LifeCycle
    - (NSMethodSignature *)methodSignatureForSelector:(SEL)selector{
        @synchronized([self class]){
            NSString *selString = NSStringFromSelector(selector);
            NSMethodSignature *signature = nil;
            NSRange range = [selString rangeOfString:@"set"];
            if (range.length) {
                signature = [NSMethodSignature signatureWithObjCTypes:"v@:@"];
            } else {
                signature = [NSMethodSignature signatureWithObjCTypes:"@@:"];
            }
            return signature;
        }
    }
    
    
    - (void)forwardInvocation:(NSInvocation *)invocation{
        NSString *key = NSStringFromSelector(invocation.selector);
        NSRange range = [key rangeOfString:@"set"];
        if (range.length) {
            key = [[key substringFromIndex:3] lowercaseString];
            id obj;
            [invocation getArgument:&obj atIndex:2];
            [self.data setObject:obj forKey:key];
            
        } else {
            id obj = self.data[key];
            [invocation setReturnValue:&obj];
        }
    }
    
    #pragma mark - Private
    - (NSMutableDictionary *)data {
        NSMutableDictionary *data = objc_getAssociatedObject(self, &dataKey);
        while (!data) {
            objc_setAssociatedObject(self, &dataKey, [NSMutableDictionary dictionary], OBJC_ASSOCIATION_COPY_NONATOMIC);
            data = objc_getAssociatedObject(self, &dataKey);
        }
        return data;
    }
    
    @end