Swift add icon/image in UITextField

I would like to add icon/image in UITextField. The icon/image should be left to placeholder.

I tried this:

var imageView = UIImageView();
var image = UIImage(named: "email.png");
imageView.image = image;
emailField.leftView = imageView;

Thanks.

Sahil has a great answer and I wanted to take that and expand it into an @IBDesignable so developers can add images to their UITextFields on the Storyboard.

Swift 4.2

import UIKit

@IBDesignable
class DesignableUITextField: UITextField {
    
    // Provides left padding for images
    override func leftViewRect(forBounds bounds: CGRect) -> CGRect {
        var textRect = super.leftViewRect(forBounds: bounds)
        textRect.origin.x += leftPadding
        return textRect
    }
    
    @IBInspectable var leftImage: UIImage? {
        didSet {
            updateView()
        }
    }
    
    @IBInspectable var leftPadding: CGFloat = 0
    
    @IBInspectable var color: UIColor = UIColor.lightGray {
        didSet {
            updateView()
        }
    }
    
    func updateView() {
        if let image = leftImage {
            leftViewMode = UITextField.ViewMode.always
            let imageView = UIImageView(frame: CGRect(x: 0, y: 0, width: 20, height: 20))
            imageView.contentMode = .scaleAspectFit
            imageView.image = image
            // Note: In order for your image to use the tint color, you have to select the image in the Assets.xcassets and change the "Render As" property to "Template Image".
            imageView.tintColor = color
            leftView = imageView
        } else {
            leftViewMode = UITextField.ViewMode.never
            leftView = nil
        }
        
        // Placeholder text color
        attributedPlaceholder = NSAttributedString(string: placeholder != nil ?  placeholder! : "", attributes:[NSAttributedString.Key.foregroundColor: color])
    }
}

What is happening here?

This designable allows you to:

• Set an image on the left
• Add padding between the left edge of the UITextField and the image
• Set a color so the image and the Placeholder text matches

Notes

• For image color to change you have to follow that note in the comment in the code
• The image color will not change in the Storyboard. You have to run the project to see the color in the Simulator/device.

Designable in the Storyboard

At Runtime

Try adding emailField.leftViewMode = UITextFieldViewMode.Always

(Default leftViewMode is Never)

Updated Answer for Swift 4

emailField.leftViewMode = UITextFieldViewMode.always

emailField.leftViewMode = .always