首先,你的对象,这是你设置它的方式,一个例子:
书.h
#import <Foundation/Foundation.h>
@interface Book : NSObject
@property (strong, nonatomic)NSString *bookID;
@property (strong, nonatomic)NSString *publishingYear;
@property (strong, nonatomic)NSString *author;
@property (strong, nonatomic)NSString *printHouse;
@property (strong, nonatomic)NSString *title;
@property (strong, nonatomic)NSString *ISBN;
-(id)initWithBookObjectId:(NSString *)bookID
publishingYear:(NSString *)publishingYear
author:(NSString *)author
printHouse:(NSString *)printHouse
title:(NSString *)title
ISBN:(NSString *)ISBN;
- (id)initWithDictionary:(PFObject *)dic;
@end
书.m
#import "Book.h"
#define NSHNullCheck(object) ([object isKindOfClass:[NSNull class]] ? nil : object)
@implementation Book
{
NSDictionary * descriptionDict;
}
-(id)initWithBookObjectId:(NSString *)bookID
publishingYear:(NSString *)publishingYear
author:(NSString *)author
printHouse:(NSString *)printHouse
title:(NSString *)title
ISBN:(NSString *)ISBN;
{
self = [super init];
if (self) {
_bookID = bookID;
_publishingYear = publishingYear;
_author = author;
_printHouse = printHouse;
_title = title;
_ISBN = ISBN;}
return self;
}
- (id)initWithDictionary:(PFObject *)dic
{
self = [self initWithBookObjectId:dic.objectId
publishingYear:NSHNullCheck([dic valueForKey:@"publishingYear"])
author:NSHNullCheck([dic valueForKey:@"author"])
printHouse:NSHNullCheck([dic valueForKey:@"printHouse"])
title:NSHNullCheck([dic valueForKey:@"title"])
ISBN:NSHNullCheck([dic valueForKey:@"ISBN"])];
descriptionDict = @{ @"sessionObjectId":_bookID,
@"teacherAge":_publishingYear,
@"teacherEmail":_author,
@"teacherFacebookuniquekey":_printHouse,
@"teacherFirstname":_title,
@"teacherGender":_ISBN};
return self;
}
- (id)init
{
self = [self initWithBookObjectId:nil
publishingYear:nil
author:nil
printHouse:nil
title:nil
ISBN:nil];
return self;
}
- (NSString *)description
{
return descriptionDict.description;
}
@end
在对象模型中存储数据:
书籍是一个包含您的“书籍对象”的数组
无论您使用 Parse 的查询从网络中提取数据的任何位置,以下 sn-p 代码都会进入。
for (PFObject *object in objects) { //"objects" here is the NSArrray returned from the parse query!
Book *book = [[Book alloc] initWithBookObjectId:object.objectId];
book.publishingYear = object[@"publishingYear"];
book.author = object[@"author"];
book.printHouse = object[@"printHouse"];
book.title = object[@"title"];
book.ISBN = object[@"isbn"];
[self.books addObject:book];
}
if ([self.searchTerm isEqualToString:@""]) {
self.filteredBooksArray = self.books;
} else {
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF.title contains[c] %@",self.searchTerm];
self.filteredBooksArray = [NSMutableArray arrayWithArray:[self.books filteredArrayUsingPredicate:predicate]];
}
[self.booksTable reloadData];
因此,这就是您使用 PFObjects 进行搜索的方式,您首先需要提取数据,将此数据保存在 NSObject 子类(数据对象模型)中,然后像在任何对象模型上一样使用正则表达式谓词进行搜索IOS中的功能。
有这个方法:
PFQuery *query = [PFQuery queryWithClassName:@"Post"]
[query whereKey:@"hashtags" containsAllObjectsInArray:@[@"#parse", @"#ftw"]];
NSArray *parseFTWPosts = [query findObjects];
然后这个方法:
/ Using PFQuery
[query whereKey:@"playerName" notEqualTo:@"Michael Yabuti"];
[query whereKey:@"playerAge" greaterThan:@18];
// Using NSPredicate
NSPredicate *predicate = [NSPredicate predicateWithFormat: @"playerName != 'Michael Yabuti' AND playerAge > 18"];
PFQuery *query = [PFQuery queryWithClassName:@"GameScore" predicate:predicate];
然后这个sn-p:
Specifying Constraints with NSPredicate
To get the most out of PFQuery we recommend using its methods listed below to add constraints. However, if you prefer using NSPredicate, a subset of the constraints can be specified by providing an NSPredicate when creating your PFQuery.
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"playerName = 'Dan Stemkosk'"];
PFQuery *query = [PFQuery queryWithClassName:@"GameScore" predicate:predicate];
let predicate = NSPredicate(format: "playerName = 'Dan Stemkosk'")
var query = PFQuery(className: "GameScore", predicate: predicate)
These features are supported:
Simple comparisons such as =, !=, <, >, <=, >=, and BETWEEN with a key and a constant.
Containment predicates, such as x IN {1, 2, 3}.
Key-existence predicates, such as x IN SELF.
BEGINSWITH expressions.
Compound predicates with AND, OR, and NOT.
Sub-queries with "key IN %@", subquery.
The following types of predicates are not supported:
Aggregate operations, such as ANY, SOME, ALL, or NONE.
Regular expressions, such as LIKE, MATCHES, CONTAINS, or ENDSWITH.
Predicates comparing one key to another.
Complex predicates with many ORed clauses.
这里还有更多:
https://github.com/ParsePlatform/Docs/blob/master/en/ios/queries.mdown