A lot of apps need more customized UI than what is available with the current set of controls. Today we’ll add a customized Check Box control since iOS does not have a Check Box. Some suggest that you use the Switch control as a replacement for the Check Box, but when developing custom apps and the client or boss want a check box, then I tend to implement a check box while others say it cannot be done. I’ll show the basics of creating a custom control for iOS of a check box.
Right click on your Xamarin iOS project and select Add Item.
In the Add New Item Window, Select “UIView” and give it a name for your custom control. After giving your control a name, click the Add button so Visual Studio add the file(s) to your project.
We need to modify the register attribute on the class to add DesignTimeVisible(true)
Now we will add any properties that we’ll need for customizing our new control and we’ll use the Visual Studio code snippet “propfull”. In the class, type propfull and hit the tab key twice.
Visual Studio will add some code to your class with default type of int and named “MyProperty” with the property type, name, name of the class and default value highlighted
You can change the different highlighted options and press the tab key to go from one highlighted option to another. In my case, I wanted a Boolean property named “IsChecked” with a default false as the default value.
We need to add an attribute Export with the property name and the property will be browsable.
Now we can start drawing portion of the custom control. Type override and select the Draw method with the CGRect argument since we’ll need to override the Draw method for the drawing.
Next in the Draw, we can draw the box for our check box control.
You can do whatever you need to do in the Draw method to create your custom control.
Have fun!
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