一般来说，我们有很多对 iOS 编程和内存管理相对较新的员工。我想构建一个应用程序，其中有几个标签显示保留计数和一些按钮来增加和减少这些保留计数。
有没有人知道那里已经有什么可行的方法，或者有任何关于设置它的建议，以便让我的观点得到理解？我有一个工作版本，但它似乎没有按照我认为的方式工作。
ViewController.h
#import <UIKit/UIKit.h>
@interface MemoryTestingViewController : UIViewController {
UILabel *retainCount;
UILabel *descLabel;
UIButton *addRetain;
UIButton *addRelease;
UIButton *access;
NSMutableString *myString;
}
@property (nonatomic, retain) IBOutlet UILabel *retainCount;
@property (nonatomic, retain) IBOutlet UILabel *descLabel;
@property (nonatomic, retain) IBOutlet UIButton *addRetain;
@property (nonatomic, retain) IBOutlet UIButton *addRelease;
@property (nonatomic, retain) IBOutlet UIButton *access;
@property (nonatomic, retain) NSMutableString *myString;
-(IBAction)pressedRetain:(id)sender;
-(IBAction)pressedRelease:(id)sender;
-(IBAction)pressedAccess:(id)sender;
@end
ViewController.m
-(IBAction)pressedAccess:(id)sender {
descLabel.text = @"Accessing myString, did we crash";
myString = [NSMutableString stringWithFormat:@"Accessing myString"];
retainCount.text = [NSString stringWithFormat:@"%i", [myString retainCount]];
}
-(IBAction)pressedRetain:(id)sender {
descLabel.text = @"Adding 1 to retain count for myString";
[myString retain];
retainCount.text = [NSString stringWithFormat:@"%i", [myString retainCount]];
}
-(IBAction)pressedRelease:(id)sender {
descLabel.text = @"Adding 1 release to myString";
[myString release];
retainCount.text = [NSString stringWithFormat:@"%i", [myString retainCount]];
}
- (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
{
// init our variable string
myString = [[NSString alloc] init];
descLabel.text = @"myString retain count after alloc/init";
// fill our label with myString's retain count starting out
retainCount.text = [NSString stringWithFormat:@"%i", [myString retainCount]];
[super viewDidLoad];
}
当它运行时，它看起来很好，但是每当我尝试按下保留按钮时就会崩溃。如果有人对如何清理它有任何建议，我将不胜感激。理想情况下，我希望他们在保留计数达到零并且应用程序崩溃时按下访问按钮，但只要保留计数为 1 或更好，访问按钮就应该工作。谢谢。