按钮的操作导致“无效选择器”崩溃——为什么？

Question

当按下我创建的按钮时，此代码会导致“无效选择器”错误。 test 函数从哪里获取？

Main.m

mainScreen = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 768, 1024)];
[self.view addSubview:mainScreen];

TaskButtons *tB = [[TaskButtons alloc] init];
[mainScreen addSubview:[tB TaskStart]]; 

TaskButtons.m

- (UIButton*)TaskStart {
   CGRect buttonFrame = CGRectMake(500, 206, 400, 35);
   UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
   button.frame = buttonFrame;
   [button setTitle:@"Task Button" forState:UIControlStateNormal];
   button.backgroundColor = [UIColor clearColor];
   button.titleLabel.textAlignment = UITextAlignmentLeft;
   button.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft;
   [button setTitleColor:[UIColor darkGrayColor] forState:UIControlStateNormal];
   [button addTarget:self action:@selector(test) forControlEvents:UIControlEventTouchUpInside];
   return button;
 }

- (void)test{
   NSLog(@"test line");
}

似乎没有调用 test 函数。此处未将按钮的 target 设置为 self 意味着它应该在 TaskButtons 类中查找名为 test 的函数>？

Answer 1

问题是 ARC 过早释放实例化对象。因此，为了解决这个问题，我需要保留更长时间。

主要.h

#import "TaskButtons.m"
@interface ViewController : UIViewController {
     TaskButtons *tB;
}

@property (nonatomic, retain) TaskButtons *tB;

Answer 2

[button addTarget:self action:@selector(test:) forControlEvents:UIControlEventTouchUpInside];

- (void)test:(id)sender{
NSLog(@"test line");
}

语法问题:) 在您的代码中替换这些行。