在代码中为UIButton设置图像

Question

如何在代码中为UIButton设置图像？我有这个：UIButton *btnTwo = [UIButton buttonWithType:UIButtonTypeRoundedRect]; btnTwo.frame = CGRectMake(40, 140, 240, 30);[btnTwo setTitle:@"vc2:v1" forState:UIControlStateNormal];[btnTwo addTarget:self action:@selector(goToOne) forControlEvents:UIControlEventTouchUpInside];[self.view addSubview:btnTwo];但看不到将为其设置图像的内容。

Answer 1

目标C

UIImage *btnImage = [UIImage imageNamed:@"image.png"];

[btnTwo setImage:btnImage forState:UIControlStateNormal];

斯威夫特4

let btnImage = UIImage(named: "image")

btnTwo.setImage(btnImage , for: UIControlState.normal)

Answer 2

Mike的解决方案将仅显示图像，但是在按钮上设置的任何标题将不可见，因为您可以设置标题或图像。

如果要同时设置（您的图像和标题），请使用以下代码：

btnImage = [UIImage imageNamed:@"image.png"];

[btnTwo setBackgroundImage:btnImage forState:UIControlStateNormal];

[btnTwo setTitle:@"Title" forState:UIControlStateNormal];

Answer 3

在此之前，我必须根据图像帧的大小显式调整按钮帧的大小。

UIImage *listImage = [UIImage imageNamed:@"list_icon.png"];

UIButton *listButton = [UIButton buttonWithType:UIButtonTypeCustom];

// get the image size and apply it to the button frame

CGRect listButtonFrame = listButton.frame;

listButtonFrame.size = listImage.size;

listButton.frame = listButtonFrame;

[listButton setImage:listImage forState:UIControlStateNormal];

[listButton addTarget:self.navigationController.parentViewController 

               action:@selector(revealToggle:) 

     forControlEvents:UIControlEventTouchUpInside];

UIBarButtonItem *jobsButton = 

  [[UIBarButtonItem alloc] initWithCustomView:listButton];

self.navigationItem.leftBarButtonItem = jobsButton;