如何在 xcode 中显示 NSTimer 的 Web 请求加载时间？
我需要在后台显示一个计时器，以分钟：秒的格式显示网络请求加载时间。当网络请求加载成功时，计时器必须停止。我的代码在这里：
@interface TimerWithWebrequestViewController : UIViewController {
IBOutlet UIWebView *webView;
IBOutlet UILabel *lbl;
int mainInt;
NSTimer *randomMain;
}
@property(nonatomic,retain) UIWebView *webView;
-(void)upDate;
@end
@implementation TimerWithWebrequestViewController
@synthesize webView;
-(void)viewDidLoad
{
NSString *urlAdd = @"http://www.google.com";
NSURL *url = [NSURL URLWithString:urlAdd];
NSURLRequest *reqObj = [NSURLRequest requestWithURL:url];
[webView loadRequest:reqObj];
[self performSelectorInBackground:@selector (upDate) withObject:nil];
}
-(void)upDate
{
mainInt = 0;
randomMain = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(randomMainVoid) userInfo:nil repeats:YES];
}
-(void)randomMainVoid{
mainInt += 1;
lbl.text = [NSString stringWithFormat:@"%d",mainInt];
}
i need to display a timer in the background for the webrequest loading time in the minutes:seconds format.When the webrequest is loaded successfully the timer has to stop.My code is here:
@interface TimerWithWebrequestViewController : UIViewController {
IBOutlet UIWebView *webView;
IBOutlet UILabel *lbl;
int mainInt;
NSTimer *randomMain;
}
@property(nonatomic,retain) UIWebView *webView;
-(void)upDate;
@end
@implementation TimerWithWebrequestViewController
@synthesize webView;
-(void)viewDidLoad
{
NSString *urlAdd = @"http://www.google.com";
NSURL *url = [NSURL URLWithString:urlAdd];
NSURLRequest *reqObj = [NSURLRequest requestWithURL:url];
[webView loadRequest:reqObj];
[self performSelectorInBackground:@selector (upDate) withObject:nil];
}
-(void)upDate
{
mainInt = 0;
randomMain = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(randomMainVoid) userInfo:nil repeats:YES];
}
-(void)randomMainVoid{
mainInt += 1;
lbl.text = [NSString stringWithFormat:@"%d",mainInt];
}
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NSTimer不是适合这项工作的工具，因为该类要求您指定时间间隔。你要做的就是运行一个“秒表”。您可以通过实现以下UIWebViewDelegate方法在加载开始时和完成时保存时间戳来实现此目的：您可以使用
NSDate作为此时间戳（调用[NSDate date]），使用time(3)函数等。取两个时间戳的差值即可得出您的时间间隔，即加载时间。NSTimeris not the right tool for this job, since the class requires you to specify a time interval. What you want to do is run a "stopwatch". You can achieve this by saving a time stamp when the load starts and when it finishes by implementing the followingUIWebViewDelegatemethods:You could use
NSDatefor this timestamp (calling[NSDate date]), using thetime(3)function, etc. Taking the difference of the two timestamps gives you your interval, i.e. your loading time.