iOS UIPopoverController委托不工作，仍然是零

Question

我已经按照几个教程/示例/答案等来尝试在popoverController中使用“取消”按钮，使用委托方法来关闭弹出窗口（本身）。我没有运气而且我被困住了。以下是相关的代码片段。

我知道cancelButtonPushed方法被成功调用，但我的黄金方法“didClickCancelButton”永远不会被调用。

任何见解？

这是我有的：

//
//  MIPracticeAreasFilterViewController.h
//

#import <UIKit/UIKit.h>

@protocol MyPopoverDelegate 
-(void)didClickCancelButton;
@end

@interface MIPracticeAreasFilterViewController : UITableViewController {
    //other vars
    id <MyPopoverDelegate> delegate;

}

//other properties
@property (nonatomic, assign) id <MyPopoverDelegate> delegate; 

//other methods    
-(IBAction)cancelButtonPush:(id)sender;

@end


//
//  MIPracticeAreasFilterViewController.m
//

#import "MIPracticeAreasFilterViewController.h"

@interface MIPracticeAreasFilterViewController()
    -(UITableViewCell *)buttonCellForTableView:(UITableView*)tableView;
    -(UITableViewCell *)submitOrCancelCellForTableView:(UITableView*)tableView;
@end

@implementation MIPracticeAreasFilterViewController
@synthesize practiceAreas=_practiceAreas;
@synthesize selectedPracticeAreas=_selectedPracticeAreas;
@synthesize delegate;

- (id)initWithStyle:(UITableViewStyle)style
{
    //init stuff
}

- (void)dealloc
{

}

- (void)didReceiveMemoryWarning
{

}

-(IBAction)cancelButtonPush:(id)sender
{
    if (self.delegate == nil)
    {
        NSLog(@"Delegate is nil. Cancel button pushed.");
    }
    //[[self delegate] didClickCancelButton];
    [self.delegate didClickCancelButton];

}

- (UITableViewCell *)submitOrCancelCellForTableView:(UITableView *)tableView
{
    static NSString *CellIdentifier = @"PracticeAreaSubmitOrCancelCell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil)
    {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }

    cell.selectionStyle = UITableViewCellSelectionStyleNone;

    NSUInteger buttonSpace = 10;
    NSUInteger buttonWidth = 120;
    NSUInteger buttonHeight = 34;
    NSUInteger buttonStartX = 80;
    NSUInteger buttonY = 4;

    UIButton *cancelButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [cancelButton addTarget:self action:@selector(cancelButtonPush:) forControlEvents:UIControlEventTouchUpInside];
    cancelButton.frame = CGRectMake(buttonStartX + buttonWidth*1 + buttonSpace*1, buttonY, buttonWidth, buttonHeight);
    [cancelButton setTitle:@"Cancel" forState:UIControlStateNormal];
    [cell.contentView addSubview:cancelButton];

    return cell;
}

#pragma mark - Table view delegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (indexPath.row == 0) {
        //clicked the "select" cell, all the handlers are their responsibility.
        return;
    }

    if (indexPath.row == 1) {
        //clicked the "submit or cancel" cell, all the handlers are their responsibility.
        return;
    }

    NSString *practiceArea = [_practiceAreas objectAtIndex:indexPath.row-2];

    if ([_selectedPracticeAreas containsObject:practiceArea]) {
        //remove the object
        [_selectedPracticeAreas removeObject:practiceArea];
    } else {
        [_selectedPracticeAreas addObject:practiceArea];
    }
    [tableView reloadData];
}

@end

这是创建popoverController的视图控制器：

//
//  MIRootViewController.h
//

#import <UIKit/UIKit.h>
#import "MILandingPageViewController.h"
#import "MIPracticeAreasFilterViewController.h"
#import "MILoginViewController.h"

@interface MIRootViewController : UIViewController <UIPopoverControllerDelegate, UITextFieldDelegate, MILoginCompleteDelegate, MIInterfaceOrientationDelegate, UINavigationControllerDelegate, MyPopoverDelegate>
{
    //other objects

    UIPopoverController *_practiceAreasPopoverController;
    MIPracticeAreasFilterViewController *_practiceAreasFilterViewController;

}

//other properties
@property (nonatomic, readwrite, retain) UIPopoverController *practiceAreasPopoverController;
@property (nonatomic, readwrite, retain) MIPracticeAreasFilterViewController *practiceAreasFilterViewController;

//other methods
- (void) didClickCancelButton;

@end

//
//  MIRootViewController.m
//

#import "MIRootViewController.h"
#import "HLReachability.h"
#import "MILoginStatusManager.h"
#import "MITextInsightDataUpdater.h"

@interface MIRootViewController ()

//other methods
- (void)didClickCancelButton;

@end

@implementation MIRootViewController

@synthesize practiceAreasPopoverController = _practiceAreasPopoverController;
@synthesize practiceAreasFilterViewController = _practiceAreasFilterViewController;

- (void)dealloc
{
    //stuff
    [super dealloc];
}

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self)
    {
        [self initialize];
    }
    return self;
}

- (void)initialize
{

    [[MIAppModel sharedInstance] preloadImages];

    _practiceAreasFilterViewController = [[MIPracticeAreasFilterViewController alloc] initWithStyle:UITableViewStylePlain];
    _practiceAreasPopoverController = [[UIPopoverController alloc] initWithContentViewController:_practiceAreasFilterViewController];
    _practiceAreasPopoverController.popoverContentSize = CGSizeMake(400, 900);
    _practiceAreasPopoverController.delegate = self;

}

#pragma mark MyPopover delegate

-(void)didClickCancelButton
{
    NSLog(@"Success! Clicked Cancel from ROOT VIEW");

    if ([_practiceAreasPopoverController isPopoverVisible])
    {
        [_practiceAreasPopoverController dismissPopoverAnimated:YES];
        [_practiceAreasPopoverController release];
    }     
}

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation
{
    //bring back the popover if it was visible before the rotation
    if (_practiceAreasPopoverControllerWasVisible) 
    {
        CGRect popoverFrame = _practiceAreasButton.superview.frame;
        popoverFrame.origin.x += _practiceAreasButton.frame.origin.x;
        popoverFrame.origin.y += _practiceAreasButton.frame.origin.y;
        popoverFrame.size = _practiceAreasButton.frame.size;
        popoverFrame.size.height = _practiceAreasButton.frame.size.height;
        [_practiceAreasPopoverController presentPopoverFromRect:popoverFrame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionDown animated:NO];
    }
    [_navController didRotateFromInterfaceOrientation:fromInterfaceOrientation];
}

- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{
    _practiceAreasPopoverControllerWasVisible = [_practiceAreasPopoverController isPopoverVisible];
    if (_practiceAreasPopoverControllerWasVisible) {
        //hide it before the rotation
        [_practiceAreasPopoverController dismissPopoverAnimated:NO];
    }
    [_navController willAnimateRotationToInterfaceOrientation:toInterfaceOrientation duration:duration];
}

#pragma mark - Actions

- (IBAction) practiceAreasTouch:(id)sender
{
    [_searchInput resignFirstResponder];
    [_practiceAreasPopoverController setDelegate:self];
    if (![_practiceAreasPopoverController isPopoverVisible]) {
        //show the popover
        CGRect popoverFrame = _practiceAreasButton.superview.frame;
        popoverFrame.origin.x += _practiceAreasButton.frame.origin.x;
        popoverFrame.origin.y += _practiceAreasButton.frame.origin.y;
        popoverFrame.size = _practiceAreasButton.frame.size;
        popoverFrame.size.height = _practiceAreasButton.frame.size.height;
        [_practiceAreasPopoverController presentPopoverFromRect:popoverFrame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionDown animated:YES];
    }
    else
    {
        [_practiceAreasPopoverController dismissPopoverAnimated:NO];
    }
}

#pragma mark - Practice Areas Filter PopoverControllerDelegate
- (void) popoverControllerDidDismissPopover:(UIPopoverController *)popoverController {
    if ([_searchInput.text isEqualToString:@""]) {
        //just use the insights
        _landingPageController.textInsights = [[MIAppModel sharedInstance] textInsightsForTopics:_practiceAreasFilterViewController.selectedTopics ];
    }
    else 
    {
        //filter by search as well
        _landingPageController.textInsights = [[MIAppModel sharedInstance] textInsightsForTopics:_practiceAreasFilterViewController.selectedTopics matchingSearch:_searchInput.text ];
    }
    [self showBackButtonAnimated:YES];
    _filterOn = YES;
    [_landingPageController.layoutView reloadDataWithInterfaceOrientation:self.interfaceOrientation];
}

@end

Answer 1

我应该抓住这个。我需要在viewController上设置委托，而不是我的popoverController。

_practiceAreasFilterViewController.delegate = self;

代替

_practiceAreasPopoverController.delegate = self;

Answer 2

尝试用initialize替换init。

当Objective-C启动你的程序时调用+(void) initialize方法，并为每个类调用它。 （见here）。

这不是初始化新对象时调用的方法，即init（或其任何变体，`initWith ...）。所以，这应该解释为什么没有设置委托。