android - Xamarin - Radial Progress Component Issue -

i 've been trying implement radialprogress component (https://components.xamarin.com/view/radialprogress) on app. managed on screen, , change progress colour can't find way change inner colour of circle.

the radialprogressview object has backgroundtintmode field takes duffporter.mode whenever try set background tint mode app breaks message (message = "no method name='setbackgroundtintmode' signature='(landroid/graphics/porterduff$mode;))

is there way want?

thanks!

yes, can done. although not in straight-forward way or maintainable way.

firstly, let's dig little radialprogressview's drawing code (as exposed xamarin studio assembly browser):

    protected override void ondraw(canvas canvas)     {         // ... there's more stuff here, idea         canvas.drawcircle(this.bgcx, this.bgcy, this.radius, this.bgcirclepaint);         canvas.drawcircle(this.bgcx, this.bgcy, this.innerlineradius, this.bgborderpaint);         canvas.drawtext(this.valuetext, this.textx, this.texty, this.textpaint);     } 

we notice colors here, bgcirclepaintand bgborderpaint. if able change value of these variables, able change color progressview painted.

the problem radialprogressview not expose fields – private, inheriting radialprogressview not allow set them new value.

however, can make use of reflection change these private fields, so:

        var textpaintmember = typeof(radialprogressview).getfield("textpaint", bindingflags.instance | bindingflags.nonpublic);         textpaintmember.setvalue(instance, mynewsupercoolcolorpaint); 

by combining two, can come new, customizable class this:

public class customizableradialprogressview : radialprogressview  {     public customizableradialprogressview(context context) : base(context)     {     }      public void settextcolor(color color)      {         var paint = new paint();         paint.settypeface(typeface.defaultbold);          paint.color = color;         paint.antialias = true;          var textpaintmember = typeof(radialprogressview).getfield("textpaint", bindingflags.instance | bindingflags.nonpublic);          textpaintmember.setvalue(this, paint);     }      public void setcirclecolor(color color)      {         var paint = new paint();         paint.setstyle(paint.style.fill);         paint.color = color;         paint.antialias = true;          var circlepaintmember = typeof(radialprogressview).getfield("bgcirclepaint", bindingflags.instance | bindingflags.nonpublic);          circlepaintmember.setvalue(this, paint);     }      public void setbordercolor(color color)      {         var paint = new paint();         paint.setstyle(paint.style.stroke);         paint.color = color;         paint.antialias = true;          var circlepaintmember = typeof(radialprogressview).getfield("bgborderpaint", bindingflags.instance | bindingflags.nonpublic);          circlepaintmember.setvalue(this, paint);     }       public void setprogresspackgroundcolor(color color)      {         var paint = new paint();         paint.setstyle(paint.style.stroke);         paint.color = color;         paint.antialias = true;          var circlepaintmember = typeof(radialprogressview).getfield("bgprogresspaint", bindingflags.instance | bindingflags.nonpublic);          circlepaintmember.setvalue(this, paint);     } } 

this result we're after:

note: wise notice making improper use of private fields: we're manipulating them outside of class live in. if xamarin ever decides change way radialprogressviewis implemented, or renames 1 of private variables, our code fail @ runtime. better way approach problem ask xamarin provide getters/setters need. but, hey, it's cooler way ;)