3. iOS写入沙盒报的错误

* Terminating app due to uncaught exception ‘NSInvalidArgumentException’, reason: ‘*
+[NSJSONSerialization dataWithJSONObject:options:error:]:
Invalid top-level type in JSON write

归档
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:_pictureArray];
NSArray *arr2 = [NSKeyedUnarchiver unarchiveObjectWithData:data];

保存到本地
NSString *path = [NSString stringWithFormat:@”%@/Documents/baikePicture.plist”,NSHomeDirectory()];
NSError* error = nil;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:data options:NSJSONWritingPrettyPrinted error:&error];
[[NSFileManager defaultManager] createFileAtPath:path contents:jsonData attributes:nil];

_pictureArray里面的元素对象是UIImage

解决办法
将UIImage转化成NSData就行了。