How to limit EditText length to 6 integers and 3 decimal places in C#(MonoDroid)?

Question

Hello, I'm new here, don't be so hard, I'm creating a project in Xamarin.Andriod using c #.

I am trying to do a validation of an EditText in Xamarin.Android (C # / MonoDroid).

The condition that I must fulfill is as follows: 'It allows entering 6 integers and 3 decimal places, in a range from 0 to 999999.999'

I have found some possible solutions in java (I don't know much and I have not been able to implement them in C #) and they are the following:

TextWatcher with Java

InputFilter with Java

I don't know how to apply it in C #, if someone could explain or give me a simple example but in C #.

this is my EditText:

                    ```<EditText
                        android:id="@+id/etVolume"
                        android:layout_width="@dimen/value_zero"
                        android:hint="Volumen"
                        android:textColor="@color/grisPrimario"
                        android:layout_height="fill_parent"
                        android:layout_weight="5"
                        android:textSize="@dimen/fluidListItem_text_size"
                        android:inputType="numberDecimal"
                        android:maxLength ="9"
                        android:textColorHint="@android:color/darker_gray"
                        android:backgroundTint="@color/grisPrimario"
                        android:gravity="bottom"
                        android:layout_marginBottom="-3dp"
                        android:layout_marginRight="@dimen/fluidListItemMarginRight"/>```

and my fragment is defined this EditText like this:

Volume = itemAdministeredFluid.FindViewById<EditText>(Resource.Id.etVolume);

etVolume.setFilters(new Android.Text.IInputFilter[] {new DecimalDigitsInputFilter(6,3)});

but i don't understand how to implement the method.

I saw that with java they use "TextWatcher" and "InputFilter" but I don't understand how to change it to C#

I appreciate any help I've spent days on this.

Thank you very much for the help.

Answer 1

It allows entering 6 integers and 3 decimal places, in a range from 0 to 999999.999'

I create IInputFilter that you can take a look:

 public class DecimalDigitsInputFilter : Java.Lang.Object, IInputFilter
{
    private double _min = 0;
    private double _max = 0;

    public DecimalDigitsInputFilter(double min, double max)
    {
        _min = min;
        _max = max;
    }

    public ICharSequence FilterFormatted(ICharSequence source, int start, int end, ISpanned dest, int dstart, int dend)
    {
        try
        {
            string val = dest.ToString().Insert(dstart, source.ToString());
            if (val.Contains("."))
            {
                string[] array = val.Split(".");
                string value1 = array[0].ToString();
                string value2 = array[1].ToString();

                if (value1.Length > 6|| value1=="")
                {                      
                }
                else
                {
                    if(value2!="" && value2.Length<=3)
                    {
                        double input = double.Parse(val);
                        if (IsInRange(_min, _max, input))
                            return null;

                    }
                    else if(value2=="")
                    {
                        if(IsInRange(_min,_max,double.Parse(value1)))
                        {
                            return null;
                        }
                    }                      
                }
            }
            else
            {
               if(val.Length<=6)
                {
                    double input = double.Parse(val);
                    if (IsInRange(_min, _max, input))
                        return null;
                }                                   
            }                 

        }
        catch (System.Exception ex)
        {
            Console.WriteLine("FilterFormatted Error: " + ex.Message);
        }

        return new Java.Lang.String(string.Empty);


    }
    private bool IsInRange(double min, double max, double input)
    {
        return max > min ? input >= min && input <= max : input >= max && input <= min;
    }
}

 edittext1 = FindViewById<EditText>(Resource.Id.editText1);
 edittext1.SetFilters(new Android.Text.IInputFilter[] {new DecimalDigitsInputFilter(0,999999.999) });