CODEWITHSUNDEEP
iosswiftuiview
TechChain
TechChain

Reputation: 8944

How to change color of some part of view from controller in swift?

I have created a custom UIView.I am making it's some part of color as other color using below code.

import Foundation

class BottomView:UIView {

    override func draw(_ rect: CGRect) {
        self.fillColor(with: .gray, width: 20)
    }

    func fillColor(with color:UIColor,width:CGFloat) {

        let topRect = CGRect(x:0, y:0, width : width, height: self.bounds.height);
        color.setFill()
        UIRectFill(topRect)

    }

}

Now my view has some initial part of color as gray & rest of its color is different. Now from controller if i try to change it's color to green the it is not changed from start position. It's color changed after inital color.

Please let me know how i can completely set background color to green.

Upvotes: 1

Views: 2189

Answers (1)

PGDev
PGDev

Reputation: 24341

You can use setNeedsDisplay on your bottom view and redraw it when setting the backgroundColor.

setNeedsDisplay()

Marks the receiver’s entire bounds rectangle as needing to be redrawn.

You can use this method or the setNeedsDisplay(_:) to notify the system that your view’s contents need to be redrawn. This method makes a note of the request and returns immediately. The view is not actually redrawn until the next drawing cycle, at which point all invalidated views are updated.

Example:

1. BottomView class

class BottomView:UIView
{
    var showGray = true

    override func draw(_ rect: CGRect)
    {
        if showGray
        {
            self.fillColor(with: .gray, width: 20)
        }
    }

    func fillColor(with color:UIColor,width:CGFloat)
    {
        let topRect = CGRect(x:0, y:0, width : width, height: self.bounds.height);
        color.setFill()
        UIRectFill(topRect)
    }
}

2. In your UIViewController

self.bottomView.showGray = false
self.bottomView.setNeedsDisplay()
self.bottomView.backgroundColor = .green

Upvotes: 2

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