UIButton *button=[UIButton buttonWithType:UIButtonTypeCustom];

[button setTitle:@"Click" forState:UIControlStateNormal];

[button setTitleColor:[UIColor blackColor]forState:UIControlStateNormal];

button.frame=CGRectMake(self.view.frame.origin.x+10,self.view.frame.size.height/2, self.view.frame.size.width-20, self.view.frame.size.height-500);

 button.titleLabel.font=[UIFont fontWithName:@"Helvetica" size:20];

[button addTarget:selfaction:@selector(aMethod)forControlEvents:UIControlEventTouchUpInside];

[button setBackgroundColor:[UIColor grayColor]];

[self.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");
 }

-(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]];

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
    }
}

对于Swift 2.2(带有新的“selector”声明)。

let btn = UIButton(type: UIButtonType.System) as UIButton
btn.frame = CGRectMake(0, 0, 100, 20) // set any frame you want
btn.setTitle("MyAction", forState: UIControlState.Normal)
btn.addTarget(self, action: #selector(MyClass.myAction(_:)), forControlEvents: UIControlEvents.TouchUpInside)
self.view.addSubview(btn)


func myAction(sender:UIButton!){
  // Some action 
}

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。