xamarin.forms - How to keep BaseView's two-way bindable Properties and event when using CustomRenderer : ViewRenderer<A, B> -

first wanna use custom uitextfield named jvfloatlabeledentry in x.f. here reference custom uitextfield https://github.com/gshackles/jvfloatsharp

so here steps:

xf side: 1. jvfloatlabeledentry.cs

public class jvfloatlabeledentry : entry     {         public color floatinglabelcolor { get; private set;}         public color floatinglabelactivecolor { get; private set;}          public jvfloatlabeledentry () : base()         {             widthrequest = 300;             heightrequest = 44;             floatinglabelcolor = color.gray;             floatinglabelactivecolor = color.black;         }                } 

ios side: 2. jvfloatlabeledtextfield.cs custom uitextfield wanna use. can find file in github https://github.com/gshackles/jvfloatsharp 3. jvfloatlabeledentryrenderer.cs customrenderer creates brand new jvfloatlabeledtextfield , sets nativecontrol

[assembly: exportrenderer (typeof (jvfloatlabeledentry), typeof (jvfloatlabeledentryrenderer))] namespace dutyfreecollection.ios {     public class jvfloatlabeledentryrenderer : viewrenderer<jvfloatlabeledentry, jvfloatlabeledtextfield>     {         public jvfloatlabeledentryrenderer () {}          protected override void onelementchanged (elementchangedeventargs<jvfloatlabeledentry> e)         {             base.onelementchanged (e);              var jfflentry = e.newelement;             if (jfflentry != null) {                 const float jvfieldhmargin = 10.0f;                 const float jvfieldfontsize = 16.0f;                 const float jvfieldfloatinglabelfontsize = 11.0f;                 // whenever use jvfloatlabeledentry on xf side, newview instead used                 var newview = new jvfloatlabeledtextfield (                     new rectanglef(jvfieldhmargin, 0, (float)jfflentry.widthrequest, (float)jfflentry.heightrequest))                 {                     text = jfflentry.text,                     placeholder = jfflentry.placeholder,                     font = uifont.systemfontofsize (jvfieldfontsize),                     clearbuttonmode = uitextfieldviewmode.whileediting,                     floatinglabelfont = uifont.boldsystemfontofsize (jvfieldfloatinglabelfontsize),                     floatinglabeltextcolor = jfflentry.floatinglabelcolor.touicolor(),                     floatinglabelactivetextcolor = jfflentry.floatinglabelactivecolor.touicolor(),                     borderstyle = uitextborderstyle.roundedrect                 };                  setnativecontrol (newview);             }         }     } } 

my problem after set new jvfloatlabeledtextfield native control, members event textchanged , properties textproperty of entry on xf side gone. i.e.

jvfloatlabeledentry floatlabeledentry = new jvfloatlabeledentry(); floatlabeledentry.textchanged += (object sender, textchangedeventargs e) => { // never comes here, event textchanged of jvfloatlabeledentry gone, why? since jvfloatlabeledentry derived entry, why event textchanged gone? }; 

same thing happens other members of custom entry,

floatlabeledentry.setbinding(jvfloatlabeledentry.textproperty, "any_binding_field"); // two-way binding gone well.

i reached bottle neck, please tell me how keep jvfloatlabeledentry(customentry)'s base class entry's properties binding , eventhandlers. thank much.

if understand question correctly problem in way initialize ios native control - there no events you're listening on native side (including lack of bindings), you're initializing native control in fire-and-forget manner.

you need add code translate native events forms events. i'm not familiar enough custom control you're using, in renderer after init control you'd need hook events, along lines:

newview.textchangedevent+=(s,e) => jfflentry.ontextchanged(jffl, new textchangedeventargs(e.newtext); 

the code above made should give idea do, if not - ask what's unclear