swift - Swift如何更改backIndicatorImage的位置和大小

我的appdelegate中有这个代码

UINavigationBar.appearance().backIndicatorImage = #imageLiteral(resourceName: "backarrow")

这段代码显示了如下内容

如何调整图像大小并更改其位置？

最佳答案

您好，您可以通过以下方式实现它：

var backImage = UIImage(named: "backarrow")
backImage = resizeImage(image: backImage!, newWidth: 40) //the width that you want for the back button image
UINavigationBar.appearance().backIndicatorImage = backImage

下面是图像大小调整函数

func resizeImage(image: UIImage, newWidth: CGFloat) -> UIImage? {

    let scale = newWidth / image.size.width
    let newHeight = image.size.height * scale
    UIGraphicsBeginImageContext(CGSize(width: newWidth, height: newHeight))
    image.draw(in: CGRect(x: 0, y: 0, width: newWidth, height: newHeight))

    let newImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

    return newImage
}