代理中的Obj-C委派 [英] Obj-C Delegate inside Delegate
问题描述
然而，我在我上面介绍了一个modalViewController， viewController。
（在我的modalViewController中，我已经实现了相同的标题，并且它从标题中获取了代理），但是如果按下了标题的后退按钮，那么它自己的这个视图必须委托给以前的viewController。 >
我已经做了相同的功能，但我的viewController从来没有得到它的委托... :(
我是相当新的Obj-C，我不知道也许我在这里做一些非法的事情。
这里是modalViewController尝试委托给以前的viewController的代码
#pragma mark - header delegate
- （void）header：（header *）header backbuttonPressed：（UIButton *）sender
{
if（header ==标记）
{
NSLog（@gotBackButtonDelegate）;
//删除项数组
// _ itemSourceArray = nil;
[委托allEventsDrillPage：self backbuttonPressed： sender];
[self dismissViewControllerAnimated：YES completion：nil];
}
}
这个委托从标题视图中触发。
我以前的viewController：
- （void）allEventsDrillPage：（allEventsDrillPage *）allEventsDrillPage backbuttonPressed：（UIButton *）sender // doesn' t工作:(
{
NSLog（@取回代理!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ）;
// [self dismissViewControllerAnimated：YES completion：nil];
_drillPage = nil;
}
从未得到调用
我像这样调用modalViewController：
- （void）tableView：（UITableView *）tableView didSelectRowAtIndexPath :( NSIndexPath *） indexPath
{
[_allEventsTableView deselectRowAtIndexPath：indexPath animated：YES];
[self> _allEventsTableView setNeedsDisplay];
[self> _allEventsTableView reloadData];
_drillPage = [[allEventsDrillPage alloc] initWithDictionary：（（NSDictionary *）[_tableDataSource objectAtIndex：indexPath.row]）];
_drillPage.delegate = self;
[self presentViewController：_drillPage animated：YES completion：nil];
}
在.h文件中我做了
@interface allEvents：UIViewController< headerDelegate，UITableViewDataSource，UITableViewDelegate，allEventsDrillPageDelegate>
我没有得到我在这里缺少的东西： - /可以some1看看吗？
如果需要更多信息我将添加只是要求它。
编辑：
modalViewController内的委托协议
@class allEventsDrillPage;
@protocol allEventsDrillPageDelegate // define delegate protocol
- （void）allEventsDrillPage：（allEventsDrillPage *）allEventsDrillPage backbuttonPressed：（UIButton *）sender;
@end
@interface allEventsDrillPage：UIViewController
{
id< allEventsDrillPageDelegate> __weak代表
....
}
@property（weak，nonatomic）id< allEventsDrillPageDelegate>代表; //定义
nmh的答案是正确的。我早些时候写了一个答案，但他来得更快，所以我以为我会拿出其他部分，只是在这里添加说明。
你有这个： p>
@interface allEventsDrillPage：UIViewController
{
id< allEventsDrillPageDelegate> __weak代表
....
}
@property（weak，nonatomic）id< allEventsDrillPageDelegate>代表;
使用这个 id< allEventsDrillPageDelegate> __weak delegate; 你声明一个ivar。
使用这个 @property（weak，nonatomic）id< allEventsDrillPageDelegate>委托; 您正在声明一个属性。
由于Xcode 4.4可以自动合成。
所以这一行：
_drillPage.delegate = self;
您正通过该属性设置一个。
而不是这样：
id< allEventsDrillPageDelegate> __weak代表
所以你在这里：
[delegate allEventsDrillPage：self backbuttonPressed：sender];
您正在使用上述ivar，而不是通过该属性。
和委托因此 nil。
因此，如果您尝试使用nmh的解决方案向代理发送消息，或者：
[self.delegate allEventsDrillPage：self backbuttonPressed：sender];
它应该按预期工作。
关闭模式视图控制器的附录：
而不是将其从当前的视图控制器中解除，而将其从一个谁提出它，所以：
- （void）header：（header *）header backbuttonPressed：（UIButton *）sender
{
if（header == logo）
{
NSLog（@gotBackButtonDelegate）;
[_delegate allEventsDrillPage：self backbuttonPressed：sender];
//或self.delegate
}
}
in：
- （void）allEventsDrillPage：（allEventsDrillPage *）allEventsDrillPage backbuttonPressed：（UIButton *）sender
{
NSLog（@取回代理!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ）;
[self dismissViewControllerAnimated：YES completion：nil];
_drillPage = nil;
}
甚至更好：
（$）$（$）$（$）$（$）$（$）$（$）$（$）$ {code $ !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!）;
[self dismissViewControllerAnimated：YES完成：^ {
_drillPage = nil;
}];
}
希望这有帮助。
I have subclassed a view that I am using as header view it has some buttons delegate inside it and it works perfect .
However I am presenting a modalViewController above my viewController . (in my modalViewController I have implemented the same header , and it does get the delegates from the header) but this view it self has to delegate to the previous viewController if the back button of the header is pressed.
I have made the same functions but my viewController never gets it's delegate... :( I am quite new to Obj-C and I don't know maybe I am doing something illegal here.
here is the code of modalViewController trying to delegate to the previous viewController
#pragma mark - header delegate
- (void)header:(header *)header backbuttonPressed:(UIButton *)sender
{
if(header == logo)
{
NSLog(@"gotBackButtonDelegate");
//delete the items array
//_itemSourceArray = nil;
[delegate allEventsDrillPage:self backbuttonPressed:sender];
[self dismissViewControllerAnimated:YES completion:nil];
}
}
This delegate does triggers from the header view.
however in my previous viewController:
- (void)allEventsDrillPage:(allEventsDrillPage *)allEventsDrillPage backbuttonPressed:(UIButton *)sender //doesn't work :(
{
NSLog(@"got back delegate!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
// [self dismissViewControllerAnimated:YES completion:nil];
_drillPage = nil;
}
never get called
I calling the modalViewController like this:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[_allEventsTableView deselectRowAtIndexPath:indexPath animated:YES];
[self->_allEventsTableView setNeedsDisplay];
[self->_allEventsTableView reloadData];
_drillPage = [[allEventsDrillPage alloc]initWithDictionary:((NSDictionary*) [_tableDataSource objectAtIndex:indexPath.row])];
_drillPage.delegate = self;
[self presentViewController:_drillPage animated:YES completion:nil];
}
in its .h file I did
@interface allEvents : UIViewController <headerDelegate , UITableViewDataSource , UITableViewDelegate ,allEventsDrillPageDelegate>
I don't get what am I missing here :-/ can some1 take a look please ? if needed more info I will added just ask for it.
EDIT:
protocol of delegate inside the modalViewController
@class allEventsDrillPage;
@protocol allEventsDrillPageDelegate //define delegate protocol
- (void)allEventsDrillPage:(allEventsDrillPage*)allEventsDrillPage backbuttonPressed:(UIButton*)sender;
@end
@interface allEventsDrillPage : UIViewController
{
id<allEventsDrillPageDelegate> __weak delegate;
....
}
@property (weak, nonatomic) id <allEventsDrillPageDelegate> delegate; //define
nmh's answer is correct. I wrote up an answer earlier but his came in faster, so I thought I would take out the other parts and just add the explanations here.
You have this:
@interface allEventsDrillPage : UIViewController
{
id<allEventsDrillPageDelegate> __weak delegate;
....
}
@property (weak, nonatomic) id <allEventsDrillPageDelegate> delegate;
With this id<allEventsDrillPageDelegate> __weak delegate; you declare an ivar.
With this @property (weak, nonatomic) id <allEventsDrillPageDelegate> delegate; you are declaring a property.
Since Xcode 4.4 you get auto-synthesization. And so this line:
_drillPage.delegate = self;
You are setting the one via the property.
And not this:
id<allEventsDrillPageDelegate> __weak delegate;
So what you have here:
[delegate allEventsDrillPage:self backbuttonPressed:sender];
You are using the ivar above, not the one via the property.
And delegate is thus nil.
And so, if you try to send a message to the delegate using nmh's solution or:
[self.delegate allEventsDrillPage:self backbuttonPressed:sender];
It should work as expected.
Addendum to dismissing modal view controller:
Instead of dismissing it from the current view controller, dismiss it from the one who presented it, so:
- (void)header:(header *)header backbuttonPressed:(UIButton *)sender
{
if(header == logo)
{
NSLog(@"gotBackButtonDelegate");
[_delegate allEventsDrillPage:self backbuttonPressed:sender];
//or self.delegate
}
}
And in:
- (void)allEventsDrillPage:(allEventsDrillPage *)allEventsDrillPage backbuttonPressed:(UIButton *)sender
{
NSLog(@"got back delegate!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
[self dismissViewControllerAnimated:YES completion:nil];
_drillPage = nil;
}
Or even better:
- (void)allEventsDrillPage:(allEventsDrillPage *)allEventsDrillPage backbuttonPressed:(UIButton *)sender
{
NSLog(@"got back delegate!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
[self dismissViewControllerAnimated:YES completion:^{
_drillPage = nil;
}];
}
Hope this helps.
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