Best approach for show/hide password toggle functionality in Xamarin traditional approach

Recently, Microsoft MVP Charlin, wrote an article showing how to do this using Event Triggers in the Xamarin Forms code:

She was able to do it simply using a new ShowPasswordTriggerAction of type TriggerAction that implemented INotifyPropertyChanged. Therein, she created a HidePassword bool property that Invoke a PropertyChanged event which changes the Source of the Icon image:

protected override void Invoke(ImageButton sender)
{
    sender.Source = HidePassword ? ShowIcon : HideIcon;
    HidePassword = !HidePassword;
}

Then place the Entry and ImageButton inside a layout (like a Frame or horizontally oriented LinearLayout) as shown:

  <Entry Placeholder="Password"
         IsPassword="{Binding Source={x:Reference ShowPasswordActualTrigger}, Path=HidePassword}"/>
  <ImageButton VerticalOptions="Center"
               HeightRequest="20"
               HorizontalOptions="End"
               Source="ic_eye_hide">
                   <ImageButton.Triggers>
                        <EventTrigger Event="Clicked">
                             <local:ShowPasswordTriggerAction ShowIcon="ic_eye"
                                                              HideIcon="ic_eye_hide"
                                                              x:Name="ShowPasswordActualTrigger"/>
                         </EventTrigger>
                  </ImageButton.Triggers>
  </ImageButton>

We always use custom controls to show/hide password while entering the password using effects.

Android:

Create the control manually in ‘OnDrawableTouchListener’ method where, we are adding the ShowPass and HidePass icons to the entry control, changing them on the basis of user touch action and attaching it on effect invocation which will be fired when the effect is added to the control.

public class OnDrawableTouchListener : Java.Lang.Object, Android.Views.View.IOnTouchListener  
{  
    public bool OnTouch(Android.Views.View v, MotionEvent e)  
    {  
        if (v is EditText && e.Action == MotionEventActions.Up)  
        {  
            EditText editText = (EditText)v;  
            if (e.RawX >= (editText.Right - editText.GetCompoundDrawables()[2].Bounds.Width()))  
            {  
                if (editText.TransformationMethod == null)  
                {  
                    editText.TransformationMethod = PasswordTransformationMethod.Instance;  
                    editText.SetCompoundDrawablesRelativeWithIntrinsicBounds(0, 0, Resource.Drawable.ShowPass, 0);  
                }  
                else  
                {  
                    editText.TransformationMethod = null;  
                    editText.SetCompoundDrawablesRelativeWithIntrinsicBounds(0, 0, Resource.Drawable.HidePass, 0);  
                }  

                return true;  
            }  
        }  

        return false;  
    }  
}  

Result:

IOS:

Create the control manually in 'ConfigureControl' method where we are adding the ShowPass and HidePassicons to the entry control, changing them on the basis of user touch action; and attaching it on effect invocation which will be fired when the effect will be added to the control.

private void ConfigureControl()  
    {  
        if (Control != null)  
        {  
            UITextField vUpdatedEntry = (UITextField)Control;  
            var buttonRect = UIButton.FromType(UIButtonType.Custom);  
            buttonRect.SetImage(new UIImage("ShowPass"), UIControlState.Normal);  
            buttonRect.TouchUpInside += (object sender, EventArgs e1) =>  
            {  
                if (vUpdatedEntry.SecureTextEntry)  
                {  
                    vUpdatedEntry.SecureTextEntry = false;  
                    buttonRect.SetImage(new UIImage("HidePass"), UIControlState.Normal);  
                }  
                else  
                {  
                    vUpdatedEntry.SecureTextEntry = true;  
                    buttonRect.SetImage(new UIImage("ShowPass"), UIControlState.Normal);  
                }  
            };  

            vUpdatedEntry.ShouldChangeCharacters += (textField, range, replacementString) =>  
            {  
                string text = vUpdatedEntry.Text;  
                var result = text.Substring(0, (int)range.Location) + replacementString + text.Substring((int)range.Location + (int)range.Length);  
                vUpdatedEntry.Text = result;  
                return false;  
            };  


            buttonRect.Frame = new CoreGraphics.CGRect(10.0f, 0.0f, 15.0f, 15.0f);  
            buttonRect.ContentMode = UIViewContentMode.Right;  

            UIView paddingViewRight = new UIView(new System.Drawing.RectangleF(5.0f, -5.0f, 30.0f, 18.0f));  
            paddingViewRight.Add(buttonRect);  
            paddingViewRight.ContentMode = UIViewContentMode.BottomRight;  


            vUpdatedEntry.LeftView = paddingViewRight;  
            vUpdatedEntry.LeftViewMode = UITextFieldViewMode.Always;  

            Control.Layer.CornerRadius = 4;  
            Control.Layer.BorderColor = new CoreGraphics.CGColor(255, 255, 255);  
            Control.Layer.MasksToBounds = true;  
            vUpdatedEntry.TextAlignment = UITextAlignment.Left;  
        }  

    }  

Result:

For more details, please refer to the article below. https://www.c-sharpcorner.com/article/xamarin-forms-tip-implement-show-hide-password-using-effects/

You could download the source file from GitHub for reference. https://github.com/techierathore/ShowHidePassEx.git

You can use the PhantomLib library to do this. It has a control which allows you to have a show/hide icon for the password with examples. Just install the nuget. https://github.com/OSTUSA/PhantomLib

Your UI codes like this having a entry and image button source to named accroding to your ui

<Frame CornerRadius="30" Background="white" Padding="0" HeightRequest="43" Margin="0,17,0,0">
                <StackLayout Orientation="Horizontal">
                    <Entry x:Name="eLoginPassword"                        
                            Margin="15,-10,0,-15"
                            HorizontalOptions="FillAndExpand"                            
                            IsPassword="True"
                            Placeholder="Password"/>
                    <ImageButton
                            x:Name="ibToggleLoginPass"
                            Clicked="IbToggleLoginPass"
                            Source="eyeclosed"
                            Margin="0,0,13,0"
                            BackgroundColor="White"
                            HorizontalOptions="End"
                            />
                </StackLayout>
            </Frame>

in C# code

 // IbToggleLoginPass your defined method in xaml
    //"eye" is drawable name for open eye and "eyeclosed" is drawable name for closed eye
    private void IbToggleLoginPass(object sender, EventArgs e)
            {
                bool isPass = eLoginPassword.IsPassword;
                ibToggleLoginPa`enter code here`ss.Source = isPass ? "eye" : "eyeclosed";
                eLoginPassword.IsPassword = !isPass;
            }

Trigger and a command

The trigger changes the icon, and the command changes the entry.

View xaml

<Grid>
      <Entry Placeholder="Password" Text="{Binding Password, Mode=TwoWay}" IsPassword="{Binding IsPassword}" />
      <ImageButton BackgroundColor="Transparent" WidthRequest="24" VerticalOptions="Center" TranslationY="-5" TranslationX="-10" HorizontalOptions="End"
          Command="{Binding ToggleIsPassword}"
          Source="eye"   >
          <ImageButton.Triggers>
              <DataTrigger TargetType="ImageButton" Binding="{Binding IsPassword}" Value="True" >
                  <Setter Property="Source" Value="eye-slash" />
              </DataTrigger>
          </ImageButton.Triggers>
      </ImageButton>
    </Grid>

And in my ViewModel

private bool _IsPassword = true;
public bool IsPassword
{
    get
    {
        return _IsPassword;
    }
    set
    {
        _IsPassword = value;
        RaisePropertyChanged(() => IsPassword);
    }
}
public ICommand ToggleIsPassword => new Command(() => IsPassword = !IsPassword);