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");
 }

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 *btnname = [UIButton buttonWithType:UIButtonTypeRoundedRect];

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

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

[self.view addSubview:btnname];

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];

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)