在按钮操作上传递参数:@selector

Question

我想将动态生成按钮中的电影网址传递给MediaPlayer:

[button addTarget:self action:@selector(buttonPressed:) withObject:[speakers_mp4 objectAtIndex:[indexPath row]] forControlEvents:UIControlEventTouchUpInside];

但action:@selector() withObject:不起作用？

还有其他解决方案吗？

感谢帮助!

Answer 1

编辑.找到一个更整洁的方式!

按钮可以接收的一个参数是(id)sender.这意味着您可以创建一个继承自UIButton的新按钮,该按钮允许您存储其他预期参数.希望这两个片段说明了该做什么.

  myOwnbutton.argOne = someValue
  [myOwnbutton addTarget:self action:@selector(buttonTouchUpInside:) forControlEvents:UIControlEventTouchUpInside];

和

- (IBAction) buttonTouchUpInside:(id)sender {
  MyOwnButton *buttonClicked = (MyOwnButton *)sender; 
  //do as you please with buttonClicked.argOne
}

这是我最初的建议.

有一种方法可以达到相同的效果,但它并不漂亮.假设您要为方法添加参数navigate.下面的代码不允许您传递该参数navigate.

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

为了解决这个问题,你可以将导航移动method到它自己的类,并将"参数"设置为该类的属性......

NavigationAid *navAid = [[NavigationAid alloc] init];
navAid.firstParam = someVariableOne
navAid.secondParam = someVariableTwo
[button addTarget:navAid action:@selector(navigate) forControlEvents:UIControlEventTouchUpInside];

当然,您可以将导航方法保留在原始类中,并让navAid调用它,只要它知道在哪里找到它.

NavigationAid *navAid = [[NavigationAid alloc] init];
navAid.whereToCallNavigate = self
navAid.firstParam = someVariableOne
navAid.secondParam = someVariableTwo
[button addTarget:navAid action:@selector(navigate) forControlEvents:UIControlEventTouchUpInside];

就像我说的,它不漂亮,但它对我有用,我没有发现任何人建议任何其他工作的解决方案.

Answer 2

我找到了解决方案 电话:

-(void) someMethod{
    UIButton * but;
    but.tag = 1;//some id button that you choice 
    [but addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside]; 
}

这里的方法称为:

-(void) buttonPressed : (id) sender{
    UIButton *clicked = (UIButton *) sender;
    NSLog(@"%d",clicked.tag);//Here you know which button has pressed
}

Answer 3

我部分地根据上述信息制定了解决方案.我只是设置了标题标签.文本到我要传递的字符串,并设置titleLabel.hidden = YES

像这样 :

    UIButton *imageclick = [[UIButton buttonWithType:UIButtonTypeCustom] retain];
    imageclick.frame = photoframe;
    imageclick.titleLabel.text = [NSString stringWithFormat:@"%@.%@", ti.mediaImage, ti.mediaExtension];
    imageclick.titleLabel.hidden = YES;

这样,就不需要继承或类别,也没有内存泄漏

Answer 4

您可以对名为MyButton的UIButton进行子类化,并通过MyButton的属性传递参数.

然后,从(id)发送者返回参数.