Rendering image with textview - ios

Question

I am placing a textview on a image. With following code:
var previewImageView=UIImageView()
self.previewImageView.frame = CGRect(x:0, y:0, width:UIScreen.mainScreen().bounds.width, height:UIScreen.mainScreen().bounds.height)
self.view.addSubview(self.previewImageView)
textField = UITextView(frame: CGRect(x: 0, y: self.view.bounds.height/2 - 50, width: self.view.bounds.width, height: 36))
textField.backgroundColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.6)
self.view.addSubview(textField)
It works well. But I want to render this image with textview. Then I will save it to gallery.
How can I do this?
Edit:
I tried following code but it is only rendering image not textview:
//Setup the image context using the passed image.
UIGraphicsBeginImageContext(inImage.size)
//Put the image into a rectangle as large as the original image.
inImage.drawInRect(CGRectMake(0, 0, inImage.size.width, inImage.size.height))
// Creating a point within the space that is as bit as the image.
var rect: CGRect = CGRectMake(atPoint.x, atPoint.y, inImage.size.width, inImage.size.height)
//Now Draw the text into an image.
drawText.drawRect(rect)
// Create a new image out of the images we have created
var newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()
// End the context now that we have the image we need
UIGraphicsEndImageContext()
//And pass it back up to the caller.
return newImage

Answer 1

You can render whole view into an UIImage using CGGraphicsContext. Here is an example of the code:
func imageWithView(view: UIView!) -> UIImage! {
UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.opaque, 0.0)
view.layer.renderInContext(UIGraphicsGetCurrentContext())
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}
When you pass scale = 0.0 it will take a scale of your screen.
An example of usage:
let image = imageWithView(view)
Code to save image:
UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);
More information about UIGraphicsContext and image saving can be found here.
Update:
If you want to render only specific views, then you should use CALayer, renderInContext. When you use renderInContext it does not know views.frame and draws at (0:0) in coordinate system, so you should use CGContextTranslateCTM to move coordinate system.
To render only these two views you can do:
UIGraphicsBeginImageContextWithOptions(view.bounds.size, false, 0.0)
let context = UIGraphicsGetCurrentContext()
CGContextTranslateCTM(context, previewImageView.frame.origin.x, previewImageView.frame.origin.y)
previewImageView.layer.renderInContext(context)
CGContextTranslateCTM(context, textField.frame.origin.x - previewImageView.frame.origin.x, textField.frame.origin.y - previewImageView.frame.origin.y)
textField.layer.renderInContext(context)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
Please set opaque true/false as you need. When I was testing in playground I was using not opaque views.
Update 2:
Code which should work in all scenarios:
func imageFromViews(views: [UIView]!, contextSize: CGSize!) -> UIImage {
UIGraphicsBeginImageContextWithOptions(contextSize, false, 0.0)
let context = UIGraphicsGetCurrentContext()
for view in views {
CGContextTranslateCTM(context, view.frame.origin.x, view.frame.origin.y)
view.layer.renderInContext(UIGraphicsGetCurrentContext())
CGContextTranslateCTM(context, -view.frame.origin.x, -view.frame.origin.y)
}
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}