UIButton * tmpBtn = [UIButton buttonWithType:UIButtonTypeCustom];
[tmpBtn addTarget:self action:@selector(clearCart:) forControlEvents:UIControlEventTouchUpInside];
tmpBtn.tag = k;
tmpBtn.frame = CGRectMake(45, 0, 15, 15);
[tmpBtn setBackgroundImage:[UIImage imageNamed:@"CloseButton.png"] forState:UIControlStateNormal];
[self.view addSubview:tmpBtn];

尝试这段代码来创建一个按钮，并使用不同的坐标重复它2次，当按钮被按下时，方法(myButtonClick)被调用

UIButton *editButton = [UIButton buttonWithType: UIButtonTypeCustom];
editButton.frame = CGRectMake(0, 0, width, height);
[editButton setBackgroundImage: editButtonImage forState: UIControlStateNormal];
[myButton addTarget:self action:@selector(myButtonClick:)    forControlEvents:UIControlEventTouchUpInside]; 
editButton.adjustsImageWhenHighlighted = YES;
editButton.titleLabel.text = @"Edit";
editButton.titleLabel.textColor = [UIColor whiteColor];
editButton.titleLabel.textAlignment = UITextAlignmentCenter;
editButton.titleLabel.font = [UIFont fontWithName: @"Helvetica" size: 14];
[self.view addSubview: editButton];

-(void) myButtonClick:(NSString *)myString{

   NSLog(@"you clicked on button %@", myString);
}

你可以在你的ViewDidLoad方法中实现它:

continuebtn = [[UIButton alloc]initWithFrame:CGRectMake(10, 100, view1.frame.size.width-20, 40)];
    [continuebtn setBackgroundColor:[UIColor grayColor]];
    [continuebtn setTitle:@"Continue" forState:UIControlStateNormal];
    continuebtn.layer.cornerRadius = 10;
    continuebtn.layer.borderWidth =1.0;
    continuebtn.layer.borderColor = [UIColor blackColor].CGColor;
    [continuebtn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    [continuebtn addTarget:self action:@selector(continuetonext) forControlEvents:UIControlEventTouchUpInside];
    [view1 addSubview:continuebtn];

其中continuetonext为:

-(void)continuetonext
{
    GeneratePasswordVC *u = [[GeneratePasswordVC alloc]init];
    [self.navigationController pushViewController:u animated:YES];
}

要以编程方式在控制器视图中添加一个按钮，请使用以下命令:

-(void)viewDidLoad
{
   UIButton * btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
   btn.frame = CGRectMake(0, 0, 100, 50);
   [btn setTitle:@"Hello, world!" forState:UIControlStateNormal];
   [self.view addSubview:btn];
}

要加入其中三种，冲洗并重复。

在Swift 5和Xcode 10.2中

基本上我们有两种类型的按钮。

1)系统类型按钮

2)自定义类型按钮(在自定义类型按钮中，我们可以为按钮设置背景图像)

而且这两种类型的按钮控制状态很少https://developer.apple.com/documentation/uikit/uicontrol/state

重要的州有

1)正常状态

2)选定状态

3)高亮状态

4)禁用状态……

//For system type button
let button = UIButton(type: .system)
button.frame = CGRect(x: 100, y: 250, width: 100, height: 50)
//  button.backgroundColor = .blue
button.setTitle("Button", for: .normal)
button.setTitleColor(.white, for: .normal)
button.titleLabel?.font = UIFont.boldSystemFont(ofSize: 13.0)
button.titleLabel?.textAlignment = .center//Text alighment center
button.titleLabel?.numberOfLines = 0//To display multiple lines in UIButton
button.titleLabel?.lineBreakMode = .byWordWrapping//By word wrapping
button.tag = 1//To assign tag value
button.btnProperties()//Call UIButton properties from extension function
button.addTarget(self, action:#selector(self.buttonClicked), for: .touchUpInside)
self.view.addSubview(button)

//For custom type button (add image to your button)
let button2 = UIButton(type: .custom)
button2.frame = CGRect(x: 100, y: 400, width: 100, height: 50)
//        button2.backgroundColor = .blue
button2.setImage(UIImage.init(named: "img.png"), for: .normal)
button2.tag = 2
button2.btnProperties()//Call UIButton properties from extension function
button2.addTarget(self, action:#selector(self.buttonClicked), for: .touchUpInside)
self.view.addSubview(button2)

@objc func buttonClicked(sender:UIButton) {
    print("Button \(sender.tag) clicked")
}

//You can add UIButton properties using extension
extension UIButton {
    func btnProperties() {
        layer.cornerRadius = 10//Set button corner radious
        clipsToBounds = true
        backgroundColor = .blue//Set background colour
        //titleLabel?.textAlignment = .center//add properties like this
    }
}

UIButton *custombutton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[custombutton addTarget:self
                 action:@selector(aMethod:)
       forControlEvents:UIControlEventTouchUpInside];
[custombutton setTitle:@"Click" forState:UIControlStateNormal];
custombutton.frame = CGRectMake(80.0, 110.0, 160.0, 40.0);
custombutton.titleLabel.textColor = [UIColor colorWithRed: 2.0f/255.0f green: 155.0f/255.0f blue: 213.0f/255.0f  alpha:1];
 [custombutton setImage:[UIImage imageNamed:@"hh.png"] forState:UIControlStateNormal];
 [view addSubview:custombutton];