We use cookies to give you the best experience on our website. If you continue to browse, then you agree to our privacy policy and cookie policy. Image for the cookie policy date
Unfortunately, activation email could not send to your email. Please try again.
Syncfusion Feedback

How to handle events in SfRangeSlider of Xamarin.iOS platform

Platform: Xamarin.iOS |
Control: SfRangeSlider |
Published Date: May 9, 2017 |
Last Revised Date: June 21, 2019


In our latest 2017 Volume 2, we have removed Delegate API and SFRangeSliderDelegate class from  SfRangeSlider control. Here we have explained how to hook the events using event handler instead of delegates.


The below codes explain how to hook the event using delegate class in our old implementation.


Code snippet:          

namespace DelegateToEvent{    public partial class ViewController : UIViewController    {        protected ViewController(IntPtr handle) : base(handle)        {            // Note: this .ctor should not contain any initialization logic.        }        public override void ViewDidLoad()        {            base.ViewDidLoad();            SFRangeSlider slider = new SFRangeSlider();            slider.Frame = new CoreGraphics.CGRect(10, 50, this.View.Frame.Width-20,400);            slider.Delegate =new RangeSliderDelegate();            this.View.AddSubview(slider);            // Perform any additional setup after loading the view, typically from a nib.        }        public override void DidReceiveMemoryWarning()        {            base.DidReceiveMemoryWarning();            // Release any cached data, images, etc that aren't in use.        }    }    public class RangeSliderDelegate : SFRangeSliderDelegate    {        public override void ValueChange(SFRangeSlider SFRangeSlider, nfloat value)        {            nfloat Value = value;                    }        public override void RangeValueChange(SFRangeSlider SFRangeSlider, nfloat start, nfloat end)        {            nfloat RangeStart = start;            nfloat RangeEnd = end;        }    }} 



Step 1:Include the ValueChange and RangeChange Event handler as follows.

namespace DelegateToEvent{    public partial class ViewController : UIViewController    {        protected ViewController(IntPtr handle) : base(handle)        {            // Note: this .ctor should not contain any initialization logic.        }        public override void ViewDidLoad()        {            base.ViewDidLoad();            SFRangeSlider slider = new SFRangeSlider();            slider.Frame = new CoreGraphics.CGRect(10, 50, this.View.Frame.Width - 20, 400);            //RangeSlider ValueChange event            slider.ValueChange += (sender, e) =>            {            };            //RangeSlider RangeChagne event            slider.RangeValueChange += (sender, e) =>            {            };            slider.Delegate =new RangeSliderDelegate();            this.View.AddSubview(slider);            // Perform any additional setup after loading the view, typically from a nib.        }        public override void DidReceiveMemoryWarning()        {            base.DidReceiveMemoryWarning();            // Release any cached data, images, etc that aren't in use.        }    }    public class RangeSliderDelegate : SFRangeSliderDelegate    {        public override void ValueChange(SFRangeSlider SFRangeSlider, nfloat value)        {            nfloat Value = value;        }        public override void RangeValueChange(SFRangeSlider SFRangeSlider, nfloat start, nfloat end)        {            nfloat RangeStart = start;            nfloat RangeEnd = end;        }    }} 



Step 2: Include the your business logic to new events which you have written in delegate class.

namespace DelegateToEvent{    public partial class ViewController : UIViewController    {        protected ViewController(IntPtr handle) : base(handle)        {            // Note: this .ctor should not contain any initialization logic.        }        public override void ViewDidLoad()        {            base.ViewDidLoad();            SFRangeSlider slider = new SFRangeSlider();            slider.Frame = new CoreGraphics.CGRect(10, 50, this.View.Frame.Width - 20, 400);            //RangeSlider ValueChange event            slider.ValueChange += (sender, e) =>            {                nfloat Value = e.Value;            };            //RangeSlider RangeChagne event            slider.RangeValueChange += (sender, e) =>            {                nfloat RangeStart = e.RangeStart;                nfloat RangeEnd = e.RangeEnd;            };            slider.Delegate =new RangeSliderDelegate();            this.View.AddSubview(slider);            // Perform any additional setup after loading the view, typically from a nib.        }        public override void DidReceiveMemoryWarning()        {            base.DidReceiveMemoryWarning();            // Release any cached data, images, etc that aren't in use.        }    }    public class RangeSliderDelegate : SFRangeSliderDelegate    {        public override void ValueChange(SFRangeSlider SFRangeSlider, nfloat value)        {            nfloat Value = value;        }        public override void RangeValueChange(SFRangeSlider SFRangeSlider, nfloat start, nfloat end)        {            nfloat RangeStart = start;            nfloat RangeEnd = end;        }    }




Step 3: Remove the Delegate API and the Delegate class from the sample.

namespace DelegateToEvent{    public partial class ViewController : UIViewController    {        protected ViewController(IntPtr handle) : base(handle)        {            // Note: this .ctor should not contain any initialization logic.        }        public override void ViewDidLoad()        {            base.ViewDidLoad();            SFRangeSlider slider = new SFRangeSlider();            slider.Frame = new CoreGraphics.CGRect(10, 50, this.View.Frame.Width-20,400);            //RangeSlider ValueChange event            slider.ValueChange += (sender, e) => {                nfloat Value = e.Value;            };            //RangeSlider RangeChagne event            slider.RangeValueChange += (sender, e) =>            {                nfloat RangeStart = e.RangeStart;                nfloat RangeEnd = e.RangeEnd;            };            this.View.AddSubview(slider);            // Perform any additional setup after loading the view, typically from a nib.        }        public override void DidReceiveMemoryWarning()        {            base.DidReceiveMemoryWarning();            // Release any cached data, images, etc that aren't in use.        }    }}



2X faster development

The ultimate Xamarin UI toolkit to boost your development speed.
You must log in to leave a comment

Please sign in to access our KB

This page will automatically be redirected to the sign-in page in 10 seconds.

Up arrow icon

Warning Icon You are using an outdated version of Internet Explorer that may not display all features of this and other websites. Upgrade to Internet Explorer 8 or newer for a better experience.Close Icon

Live Chat Icon For mobile
Live Chat Icon