我是使用Objective-C编程的Xcode新手。我有秒表程序。我需要点击按钮添加多个秒表。有没有办法做到这一点？
我现有的代码在这里：
stopwatchviewcontroller.h
#import <UIKit/UIKit.h>
@interface StopWatchViewController : UIViewController {
UILabel *stopWatchLabel;
IBOutlet UIButton *btnStartStop;
NSTimer *stopWatchTimer; // Store the timer that fires after a certain time
NSDate *startDate; // Stores the date of the click on the start button
}
@property (nonatomic, retain) UIButton *btnStartStop;
@property (nonatomic, retain) IBOutlet UILabel *stopWatchLabel;
- (IBAction)onStartPressed:(id)sender;
- (IBAction)onStopPressed:(id)sender;
- (IBAction)AddStopwatch:(id)sender;
@end
stopwatchviewcontroller.m
#import "StopWatchViewController.h"
@implementation StopWatchViewController
@synthesize stopWatchLabel;
- (void)dealloc
{
[stopWatchLabel release];
[super dealloc];
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
/*
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad
{
[super viewDidLoad];
}
*/
- (void)viewDidUnload
{
[self setStopWatchLabel:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
- (void)updateTimer
{
NSDate *currentDate = [NSDate date];
NSTimeInterval timeInterval = [currentDate timeIntervalSinceDate:startDate];
NSDate *timerDate = [NSDate dateWithTimeIntervalSince1970:timeInterval];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"HH:mm:ss.SSS"];
[dateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0.0]];
NSString *timeString=[dateFormatter stringFromDate:timerDate];
stopWatchLabel.text = timeString;
[dateFormatter release];
}
- (IBAction)onStartPressed:(id)sender {
if ([[btnStartStop titleForState:UIControlStateNormal]
isEqualToString:@"Start Clock"])
{
startDate = [[NSDate date]retain];
// Create the stop watch timer that fires every 10 ms
stopWatchTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/10.0
target:self
selector:@selector(updateTimer)
userInfo:nil
repeats:YES];
[btnStartStop setTitle:@"Stop Clock" forState:UIControlStateNormal];
}
else
{
//---stop the timer---
[timer invalidate];
//---change the caption back to "Start Clock"---
[btnStartStop setTitle:@"Start Clock" forState:UIControlStateNormal];
}
}
- (IBAction)AddStopwatch:(id)sender {
}
@end
我不知道在Addstopwatch方法中会做什么，PLZ任何人都为我提供了解决方案。 提前谢谢......
答案 0 :(得分：0)
如果我低估你的问题，我认为应该这样做：
首先，您必须将counter定义为int，并在0方法中为其赋予ViewDidLoad的值，编辑您的代码：< / p>
stopwatchviewcontroller.h
#import <UIKit/UIKit.h>
@interface StopWatchViewController : UIViewController {
UILabel *stopWatchLabel;
IBOutlet UIButton *btnStartStop;
IBOutlet UIButton *btnAddStopWatch;
NSTimer *stopWatchTimer; // Store the timer that fires after a certain time
NSDate *startDate; // Stores the date of the click on the start button
int counter;
}
@property (nonatomic, retain) UIButton *btnStartStop;
@property (nonatomic, retain) UIButton *btnAddStopWatch;
@property (nonatomic, retain) IBOutlet UILabel *stopWatchLabel;
- (IBAction)onStartPressed:(id)sender;
- (IBAction)onStopPressed:(id)sender;
- (IBAction)AddStopwatch:(id)sender;
@end
stopwatchviewcontroller.m #import“StopWatchViewController.h”
@implementation StopWatchViewController
@synthesize stopWatchLabel;
- (void)dealloc
{
[stopWatchLabel release];
[super dealloc];
}
- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
/*
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad
{
[super viewDidLoad];
}
*/
- (void)viewDidUnload
{
[self setStopWatchLabel:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
counter = 0;
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
- (void)updateTimer
{
NSDate *currentDate = [NSDate date];
NSTimeInterval timeInterval = [currentDate timeIntervalSinceDate:startDate];
NSDate *timerDate = [NSDate dateWithTimeIntervalSince1970:timeInterval];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"HH:mm:ss.SSS"];
[dateFormatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0.0]];
NSString *timeString=[dateFormatter stringFromDate:timerDate];
stopWatchLabel.text = timeString;
[dateFormatter release];
}
- (IBAction)onStartPressed:(id)sender {
if ([[btnStartStop titleForState:UIControlStateNormal]
isEqualToString:@"Start Clock"])
{
startDate = [[NSDate date]retain];
// Create the stop watch timer that fires every 10 ms
stopWatchTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/10.0
target:self
selector:@selector(updateTimer)
userInfo:nil
repeats:YES];
[btnStartStop setTitle:@"Stop Clock" forState:UIControlStateNormal];
}
else
{
//---stop the timer---
[timer invalidate];
//---change the caption back to "Start Clock"---
[btnStartStop setTitle:@"Start Clock" forState:UIControlStateNormal];
}
}
- (IBAction)AddStopwatch:(id)sender {
counter+= 50;
UILabel *sL = [[UILabel alloc]initWithFrame:CGRectMake(0, stopWatchLabel.frame.origin.y+counter, 320, 40)];
sL.backgroundColor = [UIColor clearColor];
sL.textAlignment = UITextAlignmentCenter;
sL.text = stopWatchLabel.text;
sL.textColor = [uiColor blackColor];
[self.view addSubview:sL];
}
@end
修改
您必须为UIButton方法
AddStopwatch: