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
    }
}

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];

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];

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

试试这个:

首先把它写在你的。h文件的viewcontroller

UIButton *btn;

现在把这个写在viewcontrollers viewDidLoad的。m文件中。

btn=[[UIButton alloc]initWithFrame:CGRectMake(50, 20, 30, 30)];
[btn setBackgroundColor:[UIColor orangeColor]];
[btn setTitle: @"My Button" forState:UIControlStateNormal];
[btn setTitleColor: [UIColor blueVolor] forState:UIControlStateNormal];
[btn.layer setBorderWidth:1.0f];
[btn.layer setBorderColor:[UIColor BlueVolor].CGColor];
//adding action programatically
[btn addTarget:self action:@selector(btnClicked:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn];

在视图控制器的。m文件中写入viewDidLoad方法的外部

- (IBAction)btnClicked:(id)sender
{
  //Write a code you want to execute on buttons click event
}