core-data

问题 I'm using Xcode 4.2.1 and trying to use a variable. I understand in xcode 4 you need to set the variable with $variable . I have in Xcode for my fetch request the variable as $currDate and my code as NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init]; [dateFormatter setDateFormat:@"YYYYMMdd"]; NSDate *currDate = [NSDate date]; NSString *currDateString = [dateFormatter stringFromDate:currDate]; NSError *error; NSFetchRequest *fetchRequest = [[[DataManager sharedInstance]

问题 I'm using Xcode 4.2.1 and trying to use a variable. I understand in xcode 4 you need to set the variable with $variable . I have in Xcode for my fetch request the variable as $currDate and my code as NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init]; [dateFormatter setDateFormat:@"YYYYMMdd"]; NSDate *currDate = [NSDate date]; NSString *currDateString = [dateFormatter stringFromDate:currDate]; NSError *error; NSFetchRequest *fetchRequest = [[[DataManager sharedInstance]

问题 I'm using Xcode 4.2.1 and trying to use a variable. I understand in xcode 4 you need to set the variable with $variable . I have in Xcode for my fetch request the variable as $currDate and my code as NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init]; [dateFormatter setDateFormat:@"YYYYMMdd"]; NSDate *currDate = [NSDate date]; NSString *currDateString = [dateFormatter stringFromDate:currDate]; NSError *error; NSFetchRequest *fetchRequest = [[[DataManager sharedInstance]

问题 I'm using Xcode 4.2.1 and trying to use a variable. I understand in xcode 4 you need to set the variable with $variable . I have in Xcode for my fetch request the variable as $currDate and my code as NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init]; [dateFormatter setDateFormat:@"YYYYMMdd"]; NSDate *currDate = [NSDate date]; NSString *currDateString = [dateFormatter stringFromDate:currDate]; NSError *error; NSFetchRequest *fetchRequest = [[[DataManager sharedInstance]

问题 I'm using Xcode 4.2.1 and trying to use a variable. I understand in xcode 4 you need to set the variable with $variable . I have in Xcode for my fetch request the variable as $currDate and my code as NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init]; [dateFormatter setDateFormat:@"YYYYMMdd"]; NSDate *currDate = [NSDate date]; NSString *currDateString = [dateFormatter stringFromDate:currDate]; NSError *error; NSFetchRequest *fetchRequest = [[[DataManager sharedInstance]

问题 I have seen many questions regarding batch deletion in Core Data, but none seem to address my issue. I am creating an iOS 9 / Swift app using Core Data. At WWDC this year, I attended the Core Data session and saw that I could use NSBatchDeleteRequest to delete large numbers of objects directly from the persistent store. This works for me for some objects but not others, and I think it has something to do with my relationships. I have an object graph consisting of Subject and Course , where

问题 I have seen many questions regarding batch deletion in Core Data, but none seem to address my issue. I am creating an iOS 9 / Swift app using Core Data. At WWDC this year, I attended the Core Data session and saw that I could use NSBatchDeleteRequest to delete large numbers of objects directly from the persistent store. This works for me for some objects but not others, and I think it has something to do with my relationships. I have an object graph consisting of Subject and Course , where

问题 I am writing an app for iOS using SwiftUI and CoreData. I am trying to solve one problem for a few days now. How to make dynamic filters using dynamically changing predicate in SwiftUI based on user input? I have followed this tutorial to learn about dynamic filters and CoreData: https://www.hackingwithswift.com/quick-start/ios-swiftui/dynamically-filtering-fetchrequest-with-swiftui After few small changes I have the following code. ContentView.swift : import SwiftUI struct ContentView: View

问题 I am writing an app for iOS using SwiftUI and CoreData. I am trying to solve one problem for a few days now. How to make dynamic filters using dynamically changing predicate in SwiftUI based on user input? I have followed this tutorial to learn about dynamic filters and CoreData: https://www.hackingwithswift.com/quick-start/ios-swiftui/dynamically-filtering-fetchrequest-with-swiftui After few small changes I have the following code. ContentView.swift : import SwiftUI struct ContentView: View

问题 I am writing an app for iOS using SwiftUI and CoreData. I am trying to solve one problem for a few days now. How to make dynamic filters using dynamically changing predicate in SwiftUI based on user input? I have followed this tutorial to learn about dynamic filters and CoreData: https://www.hackingwithswift.com/quick-start/ios-swiftui/dynamically-filtering-fetchrequest-with-swiftui After few small changes I have the following code. ContentView.swift : import SwiftUI struct ContentView: View