このリンクを確認していただけませんか。このリンクに感謝します。
ネストされたNSDictionaryでのNSNullの発生を置き換えます。
UPDATE
: I modified original a bit, and use some the function of converting nsarray to nsdictionary from this link Convert NSArray to NSDictionary, cuz I don't know anything about your code, so I try to make my json string as close as possible to be the same as yours, and it's work, see the following. :)
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
tmpDict = [[NSMutableDictionary alloc] init];
NSMutableDictionary *testDict = [[NSMutableDictionary alloc] init];
[testDict setValue:[NSNull null] forKey:@"NullValue"];
[testDict setValue:@"test" forKey:@"UnNull"];
subArr = [[NSMutableArray alloc] initWithObjects:testDict, testDict, nil];
[tmpDict setValue:[NSNull null] forKey:@"NullHere"];
[tmpDict setValue:@"wear" forKey:@"NotNull"];
[tmpDict setObject:subArr forKey:@"Array"];
myArr = [[NSMutableArray alloc] initWithObjects:tmpDict, tmpDict, nil];
NSLog(@"struct: %@", myArr);
[self dictionaryByReplacingNullsWithStrings];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void) dictionaryByReplacingNullsWithStrings {
const NSMutableDictionary *replaced = [NSMutableDictionary dictionaryWithDictionary: [self indexKeyedDictionaryFromArray:myArr]];
const id nul = [NSNull null];
const NSString *blank = @"";
for (NSString *key in [replaced allKeys]) {
const id object = [replaced objectForKey: key];
if (object == nul) {
[replaced setObject: blank forKey: key];
}
else if ([object isKindOfClass: [NSDictionary class]]) {
NSLog(@"found null inside and key is %@", key);
[replaced setObject:[self replaceNullInNested:object] forKey:key];
}
}
NSLog(@"replaced: %@", replaced);
}
- (NSMutableDictionary *)replaceNullInNested:(NSDictionary *)targetDict
{
//make it to be NSMutableDictionary in case that it is nsdictionary
NSMutableDictionary *m = [targetDict mutableCopy];
NSMutableDictionary *replaced = [NSMutableDictionary dictionaryWithDictionary: m];
const id nul = [NSNull null];
const NSString *blank = @"";
for (NSString *key in [replaced allKeys]) {
const id object = [replaced objectForKey: key];
if (object == nul) {
[replaced setObject: blank forKey: key];
}
else if ([object isKindOfClass: [NSArray class]]) {
NSLog(@"found null inside and key is %@", key);
//make it to be able to set value by create a new one
NSMutableArray *a = [object mutableCopy];
for (int i =0; i< [a count]; i++) {
for (NSString *subKey in [[a objectAtIndex:i] allKeys]) {
// NSLog(@"key: %@", subKey);
// NSLog(@"value: %@", [[object objectAtIndex:i] valueForKey:subKey]);
if ([[object objectAtIndex:i] valueForKey:subKey] == nul) {
[[object objectAtIndex:i] setValue:blank forKey:subKey];
}
}
}
//replace the updated one with old one
[replaced setObject:a forKey:key];
}
}
return replaced;
}
- (NSDictionary *) indexKeyedDictionaryFromArray:(NSArray *)array
{
id objectInstance;
NSUInteger indexKey = 0;
NSMutableDictionary *mutableDictionary = [[NSMutableDictionary alloc] init];
for (objectInstance in array)
[mutableDictionary setObject:objectInstance forKey:[NSNumber numberWithUnsignedInt:indexKey++]];
return (NSDictionary *)mutableDictionary;
}
from the code above, this is the result:
replacenullvalue[1590:11303] struct: (
{
Array = (
{
NullValue = "<null>";
UnNull = test;
},
{
NullValue = "<null>";
UnNull = test;
}
);
NotNull = wear;
NullHere = "<null>";
},
{
Array = (
{
NullValue = "<null>";
UnNull = test;
},
{
NullValue = "<null>";
UnNull = test;
}
);
NotNull = wear;
NullHere = "<null>";
}
)
2012-12-16 15:16:22.790 replacenullvalue[1590:11303] found null inside and key is 0
2012-12-16 15:16:22.790 replacenullvalue[1590:11303] found null inside and key is Array
2012-12-16 15:16:22.791 replacenullvalue[1590:11303] found null inside and key is 1
2012-12-16 15:16:22.791 replacenullvalue[1590:11303] found null inside and key is Array
2012-12-16 15:16:22.792 replacenullvalue[1590:11303] replaced: {
0 = {
Array = (
{
NullValue = "";
UnNull = test;
},
{
NullValue = "";
UnNull = test;
}
);
NotNull = wear;
NullHere = "";
};
1 = {
Array = (
{
NullValue = "";
UnNull = test;
},
{
NullValue = "";
UnNull = test;
}
);
NotNull = wear;
NullHere = "";
};
}
hope it help you :).