Hi All,
Today I am going to talk about iOS Delagates.
This example shows how to write a common delegate for a mail composer in iOS.
First I am going to crate a seperate class for invoking the MailComposer Modal view controller.
The class is named “Common”.
So Create .m and .h files for Common.
Common.h
#import <Foundation/Foundation.h>#import <MessageUI/MessageUI.h>@interface Common : NSObject{ MFMailComposeViewController *mailComposer; }@property (nonatomic, weak) id <MFMailComposeViewControllerDelegate> delegate;-(void)sendMail:(UIViewController *) cont : (NSString *) mailSubject : (NSString *) mailBody;-(void) setDelegate:(id <MFMailComposeViewControllerDelegate>)aDelegate;@end |
Now Go to Common.m and implement the methods.
#import "Common.h"@implementation Common@synthesize delegate;-(void)sendMail:(UIViewController *) cont :(NSString *) mailSubject : (NSString *) mailBody{ mailComposer = [[MFMailComposeViewController alloc]init]; [mailComposer setSubject:mailSubject]; mailComposer.mailComposeDelegate = delegate; [mailComposer setMessageBody:mailBody isHTML:NO]; [cont presentViewController:mailComposer animated:YES completion:nil]; }-(void) setDelegate:(id <MFMailComposeViewControllerDelegate>)aDelegate{ if (delegate != aDelegate) { delegate = aDelegate; }}@end |
Now Go to ViewController.h
We don’t need any declarations inside this class, just need to add the delegate
#import <UIKit/UIKit.h>#import <MessageUI/MessageUI.h>@interface ViewController : UIViewController<MFMailComposeViewControllerDelegate>{ }@end |
Now in the implementation class
ViewController.m
#import "ViewController.h"#import "Common.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad{ Common *com = [Common new]; [com setDelegate:self]; // Setting the Mail Composer delegate [com sendMail:self :@"Mail Subject" :@"Mail Body"]; }#pragma mark - mail compose delegate-(void)mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error{ if (result) { NSLog(@"Result : %d",result); } if (error) { NSLog(@"Error : %@",error); } [self dismissViewControllerAnimated:YES completion:nil]; } |
Ok. Now our MailComposer Delegate is implemented. Go on and run the application.