委托和模态视图控制器
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29-09-2019 - |
题
根据视图控制器编程指南,委托是驳斥模式视图的首选方法。
按照苹果自己的食谱示例,我已经实施了以下内容,但请继续警告说 addNameController:didAddName
找不到方法...
NameDelegate.h
@protocol NameDelegate
- (void)addNameController:(AddName *)addNameController didAddName:(NSString *)name;
@end
AddName.h
@interface AddName : UIViewController {
UITextField *nameField;
id delegate;
}
- (IBAction)doneAction;
- (id)delegate;
- (void)setDelegate:(id)newDelegate;
@property (nonatomic, retain) IBOutlet UITextField *nameField;
@end
AddName.m
- (IBAction)doneAction {
[delegate addNameController:self didAddName:[nameField text]];
}
- (id)delegate {
return delegate;
}
- (void)setDelegate:(id)newDelegate {
delegate = newDelegate;
}
ItemViewController.h
#import "NameDelegate.h"
@interface ItemViewController : UITableViewController <NameDelegate>{
}
@end
ItemViewController.m
- (void)addItem:(id)sender {
AddName *addName = [[AddName alloc] init];
addName.delegate = self;
[self presentModalViewController:addName animated:YES];
}
- (void)addNameController:(AddName *)addNameController didAddName:(NSString *)name {
//Do other checks before dismiss...
[self dismissModalViewControllerAnimated:YES];
}
我认为所有必需的元素都存在,并且位于正确的位置?
谢谢
解决方案
您尚未指定 delegate
财产的 AddName
必须符合 NameDelegate
协议。
在此中使用此代码 addName.h:
#import "NameDelegate.h"
@interface AddName : UIViewController {
UITextField *nameField;
id <NameDelegate> delegate;
}
@property(nonatomic, retain) IBOutlet UITextField *nameField;
@property(nonatomic, assign) id <NameDelegate> delegate;
- (IBAction)doneAction;
@end
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