iOS-在操作中传递参数:@selector() [英] iOS - passing arguments in action:@selector()

问题描述

我正在以编程方式向UITableViewCell添加一个按钮.按下按钮时要运行的方法是- (void) quantityDown:(id)sender rowNumber:(int)rowNum，其中rowNum是按钮出现的行.

I'm adding a button to a UITableViewCell programmatically. The method to be run when the button is pressed is - (void) quantityDown:(id)sender rowNumber:(int)rowNum, where rowNum is the row that the button appears in.

将目标添加到按钮时，Xcode会自动完成以下操作:

When adding the target to the button, Xcode autocompletes the following:

[buttonDown addTarget:self action:@selector(quantityDown:rowNumber:) forControlEvents:UIControlEventTouchUpInside];

但是无论我如何尝试，都无法将行号传递给方法.我认为代码的相关部分看起来像

But no matter what I try, I cannot pass the row number into the method. I assumed the pertinent portion of code would look like

action:@selector(quantityDown:rowNumber:indexPath.row)

但这并不能解决问题.我看过其他东西，例如

but that doesn't do the trick. I've seen other stuff like

action:@selector(quantityDown:)rowNumber:indexPath.row

和

action:@selector(quantityDown:rowNumber:)withObject:@"first" withObject:@"Second"

但是都行不通.我不需要传递第一个参数，只需传递行号.我也尝试过定义- (void) quantityDown:(int)rowNum之类的方法，然后像这样编写选择器:

But neither work. I don't need to pass a first argument, just the row number. I've also tried defining the method like - (void) quantityDown:(int)rowNum and then writing the selector like:

action:@selector(quantityDown:indexPath.row)

但这也不起作用.

有想法吗?

谢谢.

推荐答案

为什么不创建Custom UIButton class并将对象作为属性?

Why don't you make a Custom UIButton class and have the object as property?

请参阅下文.

"MyButton.h"

@interface MyButton : UIButton
@property(nonatomic, strong)MyClass *obj;
@end

"MyButton.m"

#import "MyButton.h"

@implementation MyButton

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

@end

现在将MyButton class分配给单元格/中的实际按钮，或者初始化自定义按钮，而不是普通的UIButton class并直接分配对象.

Now assign MyButton class to your actual button in the cell/ or initialize the custom button instead of normal UIButton class and assign the object directly.

在您的IBAction中，其中sender=MyButton

- (void) quantityDown:(id)sender{
   MyButton *btn  = (MyButton *)sender;
   //You get the object directly
   btn.obj;
}

通过这种方式，您实际上可以轻松地访问任意数量的属性.并且它在其他实现中也很有用.

Doing it this way you can actually access as many properties you want easily. And its useful in other implementations too.

希望有帮助.

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