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
    }
}

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];

UIButton *saveLibrary=[UIButton buttonWithType:UIButtonTypeCustom];

[saveLibrary setTitle:@"Library" forState:UIControlStateNormal];

[saveLibrary setBackgroundColor:[UIColor redColor]];

[saveLibrary addTarget:self 
action:@selector(saveOnGalleryButtonIsPressed) forControlEvents:UIControlEventTouchUpInside];

[saveLibrary setImage:[UIImage imageWithContentsOfFile:[[[NSBundle mainBundle] bundlePath] stringByAppendingString:@"/library225.png"]]forState:UIControlStateNormal];

saveLibrary.frame=CGRectMake(323, 15, 75, 75);  

[self.view addSubview:saveLibrary];

看看这段代码:

斯威夫特4.2

let frameimg = CGRect(x: 15, y: 46, width: 55, height: 70)
let btnTest = UIButton(type: .roundedRect)
btnTest.frame = frameimg
btnTest.tag = 11
btnTest.setTitle("Test Button", for: .normal)
btnTest.addTarget(self, action: #selector(self.buttonAction(sender:)), for: .touchUpInside)
btnTest.titleLabel?.font = UIFont.boldSystemFont(ofSize: 12.0)
btnTest.titleLabel?.lineBreakMode = .byWordWrapping
btnTest.titleLabel?.numberOfLines = 2
btnTest.titleLabel?.textAlignment = .center
btnTest.setTitleColor(UIColor.gray, for: .normal)
btnTest.setTitleColor(UIColor.blue, for: .selected)
btnTest.showsTouchWhenHighlighted = true
view.addSubview(btnTest)

Objective - C

CGRect frameimg = CGRectMake(15, 46, 55,70);
UIButton  *SelectionButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
SelectionButton.frame=frameimg;
SelectionButton.tag=i;
[SelectionButton setTitle:[SelectionArray objectAtIndex:0] forState:UIControlStateNormal];
[SelectionButton addTarget:self action:@selector(BtnSelected:)
                  forControlEvents:UIControlEventTouchUpInside];
[SelectionButton.titleLabel setFont:[UIFont boldSystemFontOfSize:12.0]];
SelectionButton.titleLabel.lineBreakMode = NSLineBreakByWordWrapping;
SelectionButton.titleLabel.numberOfLines = 2;
SelectionButton.titleLabel.textAlignment = NSTextAlignmentCenter;
[SelectionButton setTitleColor:[UIColor grayColor] forState:(UIControlStateNormal)];
[SelectionButton setTitleColor:[UIColor blueColor] forState:UIControlStateSelected];
[SelectionButton setShowsTouchWhenHighlighted:YES];
[self.view addSubview:SelectionButton];

我希望这段代码将为您工作。

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 * tmpBtn = [UIButton buttonWithType:UIButtonTypeCustom];
[tmpBtn addTarget:self action:@selector(clearCart:) forControlEvents:UIControlEventTouchUpInside];
tmpBtn.tag = k;
tmpBtn.frame = CGRectMake(45, 0, 15, 15);
[tmpBtn setBackgroundImage:[UIImage imageNamed:@"CloseButton.png"] forState:UIControlStateNormal];
[self.view addSubview:tmpBtn];