Swift-TableView背景图片：如何将图片居中

Question

I want to add a logo as a background image to my tableView . Image size is 50px, 50px.

I tried the code below, but this puts the image lower right corner.

    let imageView = UIImageView(image: UIImage(named: "logo"))
    imageView.contentMode = .scaleAspectFit
    imageView.layer.frame = CGRect(x: self.view.frame.midX, y: self.view.frame.midY, width: 50, height: 50)
    let tableViewBackgroundView = UIView()
    tableViewBackgroundView.addSubview(imageView)
    self.tableView.backgroundView = tableViewBackgroundView

Answer 1

There are a few points about swift that are pretty key:

1) The x and y parameters in CGRect.init(x:y:width:height:) don't refer to the center of the imageView. Instead, they are points in a coordinate system where (0, 0) is the Upper Left Corner of the view that the CGRect is being presented over, and

2) UIImageView actually inherits from UIView, so because of this you can just say

    tableView.backgroundView = imageView

You shouldn't have to fiddle around with any CGRects, I believe this code should work just fine, although you may have to fiddle with different contentMode properties to get it to display how you like.

    let imageView = UIImageView(image: UIImage(named: "logo"))
    imageView.layer.frame = CGRect(x: 0, y: 0, width: 50, height: 50)
    imageView.layer.frame.midX = tableView.layer.frame.midX 
    imageView.layer.frame.midY = tableView.layer.frame.midY
    tableView.backgroundView = imageView