如何檢測UISwitch是否開啓/關閉？

Question

我想檢測時UISwitch /關閉它

// .h 
IBOutlet UISwitch *privateSwitch; 
@property (nonatomic, retain) IBOutlet UISwitch *privateSwitch; 

//.m 
@synthesize privateSwitch; 
privateSwitch = [[UISwitch alloc] init]; 
howToDisplay = @"no"; 

// In my cellForRowsAtIndexPath 
UISwitch *privateSwitch = [[UISwitch alloc] initWithFrame:CGRectMake(199, 8, 0, 0)]; 
[privateSwitch addTarget:self action:@selector(switchToggled:) forControlEvents: UIControlEventTouchUpInside]; 
[cell.contentView addSubview:privateSwitch]; 

if ([howToDisplay isEqualToString:@"no"]) { 
    [privateSwitch setOn:NO animated:NO]; 
} else { 
    [privateSwitch setOn:YES animated:NO]; 
} 

- (void) switchToggled:(id)sender { 

if ([privateSwitch isOn]) { 
NSLog(@"its on!"); 
howToDisplay = @"yes"; 
[formDataTwo removeAllObjects]; 
[formTableView reloadData]; 
[privateSwitch setOn:YES animated:YES]; 
} else { 
NSLog(@"its off!"); 
howToDisplay = @"no"; 
[formDataTwo removeAllObjects]; 
[formDataTwo addObject:@"Facebook"]; 
[formDataTwo addObject:@"Twitter"]; 
[formDataTwo addObject:@"Flickr"]; 
[formDataTwo addObject:@"Tumblr"]; 
[formDataTwo addObject:@"Email"]; 
[formDataTwo addObject:@"MMS"]; 

[formTableView reloadData]; 
[privateSwitch setOn:NO animated:YES]; 
} 

}

然而，當我打開它，它會說，它的關閉。是什麼賦予了？

謝謝。

Answer 1

在你的cellForRowsAtIndexPath方法中，你正在聲明一個隱藏你的實例變量privateSwitch的本地變量UISwitch *privateSwitch。

在您的switchToggled:操作中，您正在使用實例變量來測試交換機的狀態，而不是在cellForRowAtIndexPath中聲明的那個。您可以使用sender參數是這樣的：

- (void) switchToggled:(id)sender { 
    UISwitch *mySwitch = (UISwitch *)sender; 
    if ([mySwitch isOn]) { 
     NSLog(@"its on!"); 
    } else { 
     NSLog(@"its off!"); 
    } 
} 

P.S：我會用UIControlEventValueChanged代替UIControlEventTouchUpInside。