我的应用程序有3次浏览
在view1中，只有一个按钮（播放级别1）可以推到veiw2并更新view2中的titlelabel
当view2加载并出现时，计时器开始递减计数并更新view2本身中的另一个标签，view2也具有暂停计时器并按下到view3的按钮
在view3中，只有一个按钮会跳回到view2并恢复计时器
我的问题是，当我从view3弹出到view2时，计时器仍然暂停
有什么帮助吗？
谢谢和亲切的问候。
view1.h
#import <UIKit/UIKit.h>
@interface view1 : UIViewController
-(IBAction)nextpage;
@end
视图1.m
#import "view1.h"
#import "view2.h"
@interface view1 ()
@end
@implementation view1
-(IBAction)nextpage{
view2 *obj = [[view2 alloc] init];
[self.navigationController pushViewController:obj animated:YES];
[obj.leveltitle setText:@"Level"];
obj.time=10;
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[self.navigationController setNavigationBarHidden:YES];
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
@end
view2.h
#import <UIKit/UIKit.h>
@interface view2 : UIViewController
{
int time;
NSTimer *timer;
BOOL paused;
}
@property (nonatomic, retain) NSTimer *timer;
@property (readwrite, nonatomic) int time;
@property (nonatomic) BOOL paused;
@property (readwrite, retain) IBOutlet UILabel *leveltitle;
@property (nonatomic, readwrite) IBOutlet UILabel *label;
-(IBAction)back;
-(IBAction)pause;
@end
view2.m
#import "view2.h"
#import "view3.h"
@interface view2 ()
@end
@implementation view2
@synthesize leveltitle, label;
@synthesize time, timer;
@synthesize paused;
-(void)countDown2
{
if (paused == NO && time>0)
{
time = time -1 ;
view3 *obj = [[view3 alloc] init];
obj.sss = time;
if (time == 0)
{
[timer invalidate];
}
[label setText:[NSString stringWithFormat:@"%i",time]];
}
}
-(IBAction)back{
[self.navigationController popViewControllerAnimated:YES];
}
-(IBAction)pause{
view3 *obj = [[view3 alloc] init];
[self.navigationController pushViewController:obj animated:YES];
paused = YES;
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
paused = NO;
timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(countDown2) userInfo:nil repeats:YES];
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
@end
view3.h
#import <UIKit/UIKit.h>
@interface view3 : UIViewController
{
int sss;
}
@property (nonatomic) int sss;
-(IBAction)back;
@end
view3.m
#import "view3.h"
#import "view2.h"
@interface view3 ()
@end
@implementation view3
@synthesize sss;
-(IBAction)back{
view2 *obj = [[view2 alloc] init];
obj.paused=NO;
obj.timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(cont) userInfo:nil repeats:YES];
//[obj.timer fire];
[self.navigationController popViewControllerAnimated:YES];
}
-(void)cont{
view2 *obj = [[view2 alloc] init];
obj.time = sss;
if (obj.paused == NO && time>0)
{
obj.time = obj.time -1 ;
if (obj.time == 0)
{
[obj.timer invalidate];
}
[obj.label setText:[NSString stringWithFormat:@"%i",obj.time]];
}
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
@end
最佳答案
这是因为在view3的back方法中，您创建了一个新的view2名称obj实例，并设置了paused=NO。但是当您弹出时，该obj与view2的瞬间不同。您需要做的是使用委托方法模式，以便view3在view2中具有回调方法，以将paused设置为NO。
有关委托方法模式的示例，请参见此SO中的示例。
编辑：示例回调代码：
对您的代码进行以下添加/更改：
在view2.h中：
#import "view3.h"
@interface view2 : UIViewController <view3Delegate>
在view2.m中：
-(IBAction)pause{
view3 *obj = [[view3 alloc] init];
obj.delegate = self; //adding this line
[self.navigationController pushViewController:obj animated:YES];
paused = YES;
}
-(void)setPausedValue:(BOOL)value //this is the new method callback from view3 to set paused value
{
paused = value;
}
在view3.h中：
#import <UIKit/UIKit.h>
@protocol view3Delegate <NSObject>
-(void) setPausedValue:(BOOL)value;
@end
@interface view3 : UIViewController
{
int sss;
}
@property (assign) id <view3Delegate> delegate;
@property (nonatomic) int sss;
-(IBAction)back;
@end
在view3.m中：
@implementation view3
@synthesize delegate;
-(IBAction)back{
// view2 *obj = [[view2 alloc] init];
// obj.paused=NO;
[self.delegate setPausedValue:NO]; //make callback and set value
obj.timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(cont) userInfo:nil repeats:YES];
//[obj.timer fire];
[self.navigationController popViewControllerAnimated:YES];
}
关于ios - 弹出View2时如何恢复计时器，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/11377133/