iOS-实战之后台返回数据为空造成程序崩溃

Love The Way You Lie 2023-10-18 20:53 10阅读 0赞

这里呢是整理的一位老鸟的东西，好东西得分享![大笑][laugh.gif]![大笑][laugh.gif]

大致实现思路就是循环便利做比较，如果发现是NSNull类型的就把值改为空字符串；这样的好处就是当数据请求回来，删除一下数据里面为<null>类型的东西，避免在直接取的时候产生程序崩溃问题；

两个方法，一个返回NSArray，一个是NSDictionary，根据需求选择

.h 文件

/\*\*  
\* 服务器返回的数据为<null>时的处理  
\*  
\* @param dic 经处理过后的数据，数据类型为字典，避免直接取数据时出现程序崩溃现象。  
\*/  
\- (NSDictionary \*)deleteEmpty:(NSDictionary \*)dic;  
  
/\*\*  
\* 服务器返回的数据为<null>时的处理  
\*  
\* @param dic 经处理过后的数据，数据类型为数组，避免直接取数据时出现程序崩溃现象。  
\*/  
\- (NSArray \*)deleteEmptyArr:(NSArray \*)arr;

.m 文件

@implementation NSObject (DeleteArrOrDeleteDicBothNull)
    
    - (NSDictionary *)deleteEmpty:(NSDictionary *)dic
    {
        NSMutableDictionary *mdic = [[NSMutableDictionary alloc] initWithDictionary:dic];
        NSMutableArray *set = [[NSMutableArray alloc] init];
        NSMutableDictionary *dicSet = [[NSMutableDictionary alloc] init];
        NSMutableDictionary *arrSet = [[NSMutableDictionary alloc] init];
        for (id obj in mdic.allKeys)
        {
            id value = mdic[obj];
            if ([value isKindOfClass:[NSDictionary class]])
            {
                NSDictionary *changeDic = [self deleteEmpty:value];
                [dicSet setObject:changeDic forKey:obj];
            }
            else if ([value isKindOfClass:[NSArray class]])
            {
                NSArray *changeArr = [self deleteEmptyArr:value];
                [arrSet setObject:changeArr forKey:obj];
            }
            else
            {
                if ([value isKindOfClass:[NSNull class]]) {
                    [set addObject:obj];
                }
            }
        }
        for (id obj in set)
        {
            mdic[obj] = @"";
        }
        for (id obj in dicSet.allKeys)
        {
            mdic[obj] = dicSet[obj];
        }
        for (id obj in arrSet.allKeys)
        {
            mdic[obj] = arrSet[obj];
        }
        
        return mdic;
    }
    
    - (NSArray *)deleteEmptyArr:(NSArray *)arr
    {
        NSMutableArray *marr = [NSMutableArray arrayWithArray:arr];
        NSMutableArray *set = [[NSMutableArray alloc] init];
        NSMutableDictionary *dicSet = [[NSMutableDictionary alloc] init];
        NSMutableDictionary *arrSet = [[NSMutableDictionary alloc] init];
        
        for (id obj in marr)
        {
            if ([obj isKindOfClass:[NSDictionary class]])
            {
                NSDictionary *changeDic = [self deleteEmpty:obj];
                NSInteger index = [marr indexOfObject:obj];
                [dicSet setObject:changeDic forKey:@(index)];
            }
            else if ([obj isKindOfClass:[NSArray class]])
            {
                NSArray *changeArr = [self deleteEmptyArr:obj];
                NSInteger index = [marr indexOfObject:obj];
                [arrSet setObject:changeArr forKey:@(index)];
            }
            else
            {
                if ([obj isKindOfClass:[NSNull class]]) {
                    NSInteger index = [marr indexOfObject:obj];
                    [set addObject:@(index)];
                }
            }
        }
        for (id obj in set)
        {
            marr[(int)obj] = @"";
        }
        for (id obj in dicSet.allKeys)
        {
            int index = [obj intValue];
            marr[index] = dicSet[obj];
        }
        for (id obj in arrSet.allKeys)
        {
            int index = [obj intValue];
            marr[index] = arrSet[obj];
        }
        return marr;
    }
    
    @end

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