从Swift 3开始，语法有了一些变化。

以下是如何创建Swift 3的基本按钮:

    let button = UIButton(type: UIButtonType.system) as UIButton
    button.frame = CGRect(x: 100, y: 100, width: 100, height: 50)
    button.backgroundColor = UIColor.green
    button.setTitle("Example Button", for: UIControlState.normal)
    self.view.addSubview(button)

以下是Swift自以前版本以来所做的更改:

let button = UIButton(type: UIButtonType.System) as UIButton

// system no longer capitalised

button.frame = CGRectMake(100, 100, 100, 50)

// CGRectMake has been removed as of Swift 3

button.backgroundColor = UIColor.greenColor()

// greenColor replaced with green

button.setTitle("Example Button", forState: UIControlState.Normal)

// normal is no longer capitalised

self.view.addSubview(button)

试一试……

UIButton *finalPriceBtn=[UIButton buttonWithType:UIButtonTypeRoundedRect];
finalPriceBtn.frame=CGRectMake(260, 25, 45, 15);
[finalPriceBtn addTarget:self action:@selector(goBtnClk:) forControlEvents:UIControlEventTouchUpInside];
finalPriceBtn.titleLabel.font=[UIFont systemFontOfSize:12];
[finalPriceBtn setTitle:[NSString stringWithFormat:@"$%.2f",tempVal] forState:UIControlStateNormal];
finalPriceBtn.titleLabel.textColor = [UIColor colorWithRed: 2.0f/255.0f green: 155.0f/255.0f blue: 213.0f/255.0f  alpha:1];
finalPriceBtn.titleLabel.textAlignment=UITextAlignmentLeft;
[imageView addSubview:finalPriceBtn];

希望我能帮上忙。

UIButton *btnname = [UIButton buttonWithType:UIButtonTypeRoundedRect];

[btnname setTitle:@"Click Me" forState:UIControlStateNormal];

btnname.frame = CGRectMake(10, 10, 100, 140);

[self.view addSubview:btnname];

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

UIButton *addProject = [UIButton buttonWithType: UIButtonTypeRoundedRect];
addProject.frame = CGRectMake(210, 285, 100, 18);
[addProject setTitle:@"Show View" forState:UIControlStateNormal];
[addProject addTarget:self action:@selector(addProjectPressed:) forControlEvents:UIControlEventTouchUpInside];
[_scrollView addSubview:addProject];

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
    }
}