为了以编程方式创建UIButton，我们可以在objective - c和swift中创建

斯威夫特3

let buttonSwift   = UIButton(type: UIButtonType.system) as UIButton
                      //OR 
let buttonSwift   = UIButton(type: UIButtonType.Custom) as UIButton
//Set Frame for Button
buttonSwift.frame = CGRect(x: 100, y: 100, width: 200, height: 100)
//Set title for button
buttonSwift.setTitle("ClickMe", for: .normal)
//If you want to set color for button title
buttonSwift.setTitleColor(UIColor.white, for: .normal)
//If you want to set Background color for button
buttonSwift.backgroundColor = UIColor.black
//If you want to set tag for button
buttonSwift.tag = 0
//If you want to add or set image for button
let image = UIImage(named: "YourImageName") as UIImage?
buttonSwift.setImage(image, for: .normal)
//If you want to add or set Background image for button
buttonSwift.setBackgroundImage(image, for: .normal)
//Add action for button
buttonSwift.addTarget(self, action: #selector(actionPressMe), for:.touchUpInside)
//Add button as SubView to Super View
self.view.addSubview(buttonSwift)

UIButton动作方法

func actionPressMe(sender: UIButton!) 
{
    NSLog("Clicked button tag is %@", sender.tag)
               OR
    print("Clicked button tag is \(sender.tag)")

    //Then do whatever you want to do here

    ........  
}

OBJECTIVE - C

UIButton *buttonObjectiveC = [UIButton buttonWithType:UIButtonTypeCustom];
           OR
UIButton *buttonObjectiveC = [UIButton buttonWithType:UIButtonTypeSystem];
buttonObjectiveC.frame = CGRectMake(200, 100, 200, 100);
//Set title for button
[buttonObjectiveC setTitle:@"ClickMe" forState:UIControlStateNormal];
//If you want to set color for button title
[buttonObjectiveC setTitleColor:[UIColor  whiteColor] forState: UIControlStateNormal];
//If you want to set Background color for button
[buttonObjectiveC setBackgroundColor:[UIColor blackColor]];
//If you want to set tag for button
buttonSwift.tag = 0;
//If you want to add or set image for button
UIImage *image = [UIImage imageNamed:@"YourImageName"];
[buttonObjectiveC setImage:image forState:UIControlStateNormal];
//If you want to add or set Background image for button
[buttonObjectiveC setBackgroundImage:image forState:UIControlStateNormal];
//Add action for button
[buttonObjectiveC addTarget:self action:@selector(actionPressMe:)forControlEvents:UIControlEventTouchUpInside];
//Add button as SubView to Super View
[self.view addSubview:buttonObjectiveC];

UIButton动作方法

- (void)actionPressMe:(UIButton *)sender 
{
    NSLog(@"Clicked button tag is %@",sender.tag);
    //Then do whatever you want to do here
    ..........
}

输出截图为

在这里你可以动态创建一个UIButton:

//For button image
UIImage *closebtnimg = [UIImage imageNamed:@"close_btn.png"];
//Custom type button
btnclose = [[UIButton buttonWithType:UIButtonTypeCustom]retain];
//Set frame of button means position
btnclose.frame = CGRectMake(103, 257, 94, 32);
//Button with 0 border so it's shape like image shape
[btnclose.layer setBorderWidth:0];
//Set title of button
[btnclose setTitle:@"CLOSE" forState:UIControlStateNormal];
[btnclose addTarget:self action:@selector(methodname:) forControlEvents:UIControlEventTouchUpInside];
//Font size of title
btnclose.titleLabel.font = [UIFont boldSystemFontOfSize:14];
//Set image of button
[btnclose setBackgroundImage:closebtnimg forState:UIControlStateNormal];

objective - c

// Create the Button with RoundedRect type
UIButton *mybutton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
// instend of "Click Me" you can write your own message/Label
[mybutton setTitle:@"Click Me" forState:UIControlStateNormal];
// create the Rectangle Frame with specified size
mybutton.frame = CGRectMake(10, 10, 300, 140); // x,y,width,height    [self.view addSubview:mybutton];// add button to your view.

斯威夫特

let button   = UIButton(type: UIButtonType.System) as UIButton
button.frame = CGRectMake(100, 100, 100, 50)
button.backgroundColor = UIColor.greenColor()
button.setTitle("Test Button", forState: UIControlState.Normal)
self.view.addSubview(button)

'action:@selector(aMethod:)'这样写方法:

- (void)aMethod:(UIButton*)button
   {
         NSLog(@"Button  clicked.");
  }

这对我很管用。谢谢。KS。

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
    }
}

拜托，都2014年了!为什么代码块评估分配还没有被使用，因为趋势表明这是未来的趋势!

UIButton* button = ({
    //initialize button with frame
    UIButton* button = [[UIButton alloc] initWithFrame:({
        CGRect frame = CGRectMake(10.0, 10.0, 200.0, 75.0);
        frame;
    })];
    //set button background color
    [button setBackgroundColor:({
        UIColor* color = [UIColor colorWithRed:1.0 green:1.0 blue:0.0 alpha:1.0];
        color;
    })];
    //set button title for state
    [button setTitle:({
        NSString* string = [NSString stringWithFormat:@"title words"];
        string;
    }) forState:({
        UIControlState state = UIControlStateNormal;
        state;
    })];
    //set selector
    [button addTarget:self action:({
        SEL select = @selector(method:);
        select;
    }) forControlEvents:({
        UIControlEvents event = UIControlEventTouchUpInside;
        event;
    })];
    //return button
    button;
});
[self.view addSubview:button];

哇!

或者确切的结果可以这样完成:

UIButton* button = [[UIButton alloc] initWithFrame:CGRectMake(10.0, 10.0, 200.0, 75.0)];
[button setBackgroundColor:[UIColor colorWithRed:1.0 green:1.0 blue:0.0 alpha:1.0]];
[button setTitle:@"title words" forState:UIControlStateNormal];
[button addTarget:self action:@selector(method:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button];