iOS UIView背景图片

Question

I want to have a UIImage as a background image on a UIView.

Here is my code:

UIColor *background = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:@"login.png"]];
self.view.backgroundColor = background;
[background release];

The Problem is, that the scale is not okay. It scaled 640 to 480, so I can't tell it 100% sure but it looks like only 300 to 250 is displayed or something like that.

Is there a fit to scale / fit to UIView / fit to size modus?

Answer 1

you are required to process your image before you add it, try this :

UIGraphicsBeginImageContext(self.view.frame.size);
[[UIImage imageNamed:@"image.png"] drawInRect:self.view.bounds];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

self.view.backgroundColor = [UIColor colorWithPatternImage:image];

Answer 2

你好试试这个，

     self.view.backgroundColor=[UIColor colorWithPatternImage:[UIImage imageNamed:@"login.png"]];

Answer 3

Specify an actual background and send it to the back of your view

//add background
UIImageView *background = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"bg.png"]];
[myView addSubview:background];
[myView sendSubviewToBack:background];
myView.contentMode = UIViewContentModeScaleAspectFit;

Answer 4

In Swift use this...

    UIGraphicsBeginImageContext(self.view.frame.size)
    UIImage(named: "1.png")?.drawInRect(self.view.bounds)

    var image: UIImage = UIGraphicsGetImageFromCurrentImageContext()

    UIGraphicsEndImageContext()

    self.view.backgroundColor = UIColor(patternImage: image)

Answer 5

According to the UIColor API:

You can use pattern colors to set the fill or stroke color just as you would a solid color. During drawing, the image in the pattern color is tiled as necessary to cover the given area.

That means it tries to create a pattern out of your image to fill the area. I think the optimal way to do it is so rescale your image to fit exactly the UIView size.

There is a nice answer here how to resize your image during runtime:

The simplest way to resize an UIImage?

Answer 6

如果你想在swift中做到这一点：

self.view.backgroundColor = UIColor(patternImage: UIImage(named:"background.jpg"))

Answer 7

I'm using the following extension in Swift:

extension UIView{

    func setBackgroundImage(img: UIImage){

        UIGraphicsBeginImageContext(self.frame.size)
        img.drawInRect(self.bounds)
        let patternImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        self.backgroundColor = UIColor(patternImage: patternImage)
    }
}

In code you can use like this:

if let image = UIImage(named: "HomeBg"){
        self.view.setBackgroundImage(image)
    }

Answer 8

In the Interface Builder, add an Image View to View and select the image you want to use in Attributes inspector . Finally, make the Image View the very first child of the View by dragging the element in Document Outline .

Answer 9

UIColor *background = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:@"image.png"]];
self.view.backgroundColor = background;
[background release];

Answer 10

If the view is going to have the same size, you can place a method in your AppDelegate.m that scales the background image on first run, and then keeps the scaled image in memory for future use:

UIImage *backgroundImage = nil;
- (void)setBackground:(UIView *)view
{
    if (backgroundImage == nil)
    {
        UIGraphicsBeginImageContext(view.frame.size);
        [[UIImage imageNamed:@"Background"] drawInRect:view.bounds];
        backgroundImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
    }
    view.backgroundColor = [UIColor colorWithPatternImage:backgroundImage];
}

Thanks to @uneakharsh for his help!

Answer 11

You can use UIGraphicsBeginImageContext method to set the size of image same that of view.

Syntax : void UIGraphicsBeginImageContext(CGSize size);

  #define IMAGE(imageName) (UIImage *)[UIImage imageWithContentsOfFile:
[[NSBundle mainBundle] pathForResource:imageName ofType:IMAGE_TYPE_PNG]]

        UIGraphicsBeginImageContext(self.view.frame.size);
        [[UIImage imageNamed:@“MyImage.png"] drawInRect:self.view.bounds];
        UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

    self.view.backgroundColor = [UIColor colorWithPatternImage:IMAGE(@"mainBg")];

Answer 12

I also wanted to do this and I found that, due to autolayout , the UIImageView stretches the containing UIView , when I want it the other way: I want the UIImageView to take the size of the UIView .

So I created this class. It updates the UIImageView frame according to the UIView container whenever it is laid out via layoutSubviews .

/**
 * View with an image whose frame is adjusted to the frame of the view. 
 */
class ViewWithImage: UIView {

    let image: UIImageView

    init(image: UIImageView) {
        self.image = image
        super.init(frame: .zero)
        self.addSubview(image)
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        updateImageFrame()
    }

    private func updateImageFrame() {
        image.frame = CGRect(origin: .zero, size: self.frame.size)
    }

    required init?(coder: NSCoder) { fatalError("no init(coder:)") }
}

Answer 13

this.View.BackgroundColor = UIColor.FromPatternImage (UIImage.FromFile ("body_background.png"));