[Transfer of]ios data

Scenario 1:a-->b need to pass data to B.

Code:

• Jump--Execute login2contacts this segue
• [self performseguewithidentifier:@ "login2contacts" sender: nil];
• When the Performseguewithidentifier jump is performed, the Prepareforsegue method is called, and Viewcontroller is taken in Prepareforsegue to pass the data
• /**
• * After executing segue, this method is called before jumping
• * Typically here to pass data to the next controller
• */
• -(void) Prepareforsegue: (uistoryboardsegue *) Segue sender: (ID) sender
• {
• //1. Get the target controller (contact list Controller)
• Uiviewcontroller *CONTACTVC = Segue. Destinationviewcontroller;
• //2. Set the title
• CONTACTVC. title = [NSString stringwithformat:"%@ contact list", self . Accountfield. Text];
• //Contactvc.title equivalent to ContactVc.navigationItem.title
• ContactVc.navigationItem.title = [NSString stringwithformat:@ "%@ contact list", Self.accountField.text];
• }

Scenario 2 B->a When entering B, the B operation is completed to return to a, need to bring back the data to a
Idea, to let B pass to a first create a proxy object, that is, a new protocol, a to implement this Protocol, that a is equivalent to a proxy, and then a proxy into B, B to invoke the protocol in a method
Code:

• #import <UIKit/UIKit.h>
• @class Mjaddviewcontroller, Mjcontact;
• @protocol mjaddviewcontrollerdelegate <NSObject>
• @optional
• -(void) Addviewcontroller: (Mjaddviewcontroller *) ADDVC didaddcontactwithname: (NSString *) name Phone: (NSString *) Phone
• -(void) Addviewcontroller: (mjaddviewcontroller *) ADDVC didaddcontact: (mjcontact *) Contact;
• @end
• @interface Mjaddviewcontroller:uiviewcontroller
• @property (nonatomic, weak) id<mjaddviewcontrollerdelegate> delegate;
• @end
• /**
• * Add
• */
• -(ibaction) Add {
• //1. Close the current controller
• [self. Navigationcontroller popviewcontrolleranimated:YES];
• //2. Pass data to previous controller (Mjcontactsviewcontroller)
• //2. Notification Agent
• if ([self. Delegate Respondstoselector:@selector (addviewcontroller:didaddcontact:)]) {
• mjcontact *contact = [[Mjcontact alloc] init];
• Contact. Name = self. NameField. Text;
• Contact. Phone = self. Phonefield. Text;
• [Self-delegate Addviewcontroller:self didaddcontact:contact];
• }
• }
• A file
• @interface Mjcontactsviewcontroller () <MJAddViewControllerDelegate>
• /**
• * Called before the jump is executed
• * In this method, the view of the target controller has not been created
• */
• -(void) Prepareforsegue: (uistoryboardsegue *) Segue sender: (ID) sender
• {
• ID VC = Segue. Destinationviewcontroller;
• //Set up a proxy for the next controller (add a contact's director)
• Mjaddviewcontroller *ADDVC = VC;
• ADDVC. Delegate = self ;
• }
• Proxy methods for #pragma mark-mjaddviewcontroller
• -(void) Addviewcontroller: (mjaddviewcontroller *) ADDVC didaddcontact: (mjcontact *) Contact
• {
• //1. Add Model Data
• [self. Contacts Addobject:contact];
• //2. Refresh the table
• [self. TableView Reloaddata];
• }

[Transfer of]ios data