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)

-(UIButton *)addButton:(NSString *)title :(CGRect)frame : (SEL)selector :(UIImage *)image :(int)tag{

UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
btn.frame = frame;
[btn addTarget:self action:selector forControlEvents:UIControlEventTouchUpInside];
[btn setTitle:title forState:UIControlStateNormal];
[btn setImage:image forState:UIControlStateNormal];
btn.backgroundColor = [UIColor clearColor];
btn.tag = tag;

return btn;

}

你可以把它添加到视图中:

[self.view addSubview:[self addButton:nil :self.view.frame :@selector(btnAction:) :[UIImage imageNamed:@"img.png"] :1]];

UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button addTarget:self 
       action:@selector(aMethod:)
 forControlEvents:UIControlEventTouchDown];
[button setTitle:@"Show View" forState:UIControlStateNormal];
button.frame = CGRectMake(80.0, 210.0, 160.0, 40.0);
[view addSubview:button];

你可以通过这段代码创建按钮。

 UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
 [btn addTarget:self action:@selector(btnAction) forControlEvents:UIControlEventTouchDragInside];
 [btn setTitle:@"click button" forState:UIControlStateNormal];
  btn.frame = CGRectMake(50, 100, 80, 40);
  [self.view addSubview:btn];

下面是按钮动作方法

 -(void)btnAction
 {
   NSLog(@"button clicked");
 }

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。

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
    }
}