String.Format没有在Xamarin.Forms中提供正确的字符串

Question

I want to display text in a format in label, but it's displaying an incorrect value.

It's showing the correct value in debug mode. But its displayed wrong on the screen. Ideally, the screen should display total and subtotal as image one.

Code to format string

string paymentFormat = "{0,-25} {1,8}\n";
string paymentMode = "Total"; // Or Subtotal
string paymentAmount = "604.00";

string test = string.Format(paymentFormat, paymentMode, paymentAmount);

Update

public class AlertPopupViewItem : ContentView
{
    Label HeaderLabel,MessageLabel;
    public Button OKButton, CancelButton;
    AbsoluteLayout _overlay;
    LoggerService logservice;
    public bool ButtonValue = false;
    StackLayout CancelStackLayout, OKStackLayout;
    string PageSource = string.Empty;

    public AlertPopupViewItem()
    {
        logservice = new LoggerService();
        logservice.WriteData(Constants.DEBUG_LOGGING, "Alert Message Popup ctor.. Start");

        _overlay = new AbsoluteLayout
        {
            BackgroundColor = Color.Black.MultiplyAlpha(0.5),
            HorizontalOptions = LayoutOptions.Fill,
            VerticalOptions = LayoutOptions.Fill,
        };

        Grid mainGrid = new Grid
        {
            HeightRequest = 40,
            BackgroundColor = Color.White,
            Padding = 20,
            RowDefinitions =
            {

                new RowDefinition { Height = new GridLength(15, GridUnitType.Star) },//0 Title
                new RowDefinition { Height = new GridLength(3, GridUnitType.Star) },//1 Line
                new RowDefinition { Height = new GridLength(80, GridUnitType.Star) },//2 Message
                new RowDefinition { Height = new GridLength(12, GridUnitType.Star) },//3 OK-Cancel
            }
        };

        HeaderLabel = new Label
        {
            FontAttributes = FontAttributes.Bold,
            FontSize = 22,
            TextColor = Color.Black,
            HorizontalTextAlignment= TextAlignment.Center,
            VerticalTextAlignment = TextAlignment.Center,
            HorizontalOptions = LayoutOptions.CenterAndExpand,
            VerticalOptions =LayoutOptions.CenterAndExpand
        };


        BoxView divider = new BoxView
        {
            HeightRequest = 1,
            Color = Color.Gray,
            VerticalOptions = LayoutOptions.End,
        };



        MessageLabel = new Label
        {
            FontAttributes = FontAttributes.None,
            FontSize = 13,
            HorizontalTextAlignment = TextAlignment.Start,
            VerticalTextAlignment = TextAlignment.Center,
            HorizontalOptions = LayoutOptions.StartAndExpand,
            TextColor = Color.Black
        };

        ScrollView scroll = new ScrollView()
        {
            Orientation = ScrollOrientation.Vertical
        };

        scroll.Content = MessageLabel;

        Grid ButtonGrid = new Grid
        {

            HeightRequest = 35,
            ColumnDefinitions =
            {
                new ColumnDefinition {Width=new GridLength(58,GridUnitType.Star) },
                new ColumnDefinition {Width=new GridLength(20,GridUnitType.Star) },
                new ColumnDefinition {Width=new GridLength(2,GridUnitType.Star) },
                new ColumnDefinition {Width=new GridLength(20,GridUnitType.Star) }
            }
        };


        CancelStackLayout = new StackLayout
        {
            Padding = new Thickness(-6, -6, -6, -6),
            //VerticalOptions = LayoutOptions.Center,
            BackgroundColor = Color.FromHex("#ff9500")
        };

        CancelButton = new Button
        {
            TextColor = Color.White,
            FontSize = 15,
            BorderRadius = 0,
            Text = Localizer.Localize("CancelSmall"),
            BackgroundColor = Color.FromHex("#01458e"),
            HorizontalOptions =LayoutOptions.FillAndExpand,
            VerticalOptions=LayoutOptions.FillAndExpand,
            BorderColor = Color.Transparent
        };


        CancelButton.Clicked += CancelButtonClicked;

        CancelStackLayout.Children.Add(CancelButton);
        ButtonGrid.Children.Add(CancelStackLayout, 1, 0);

        OKStackLayout = new StackLayout
        {
            Padding = new Thickness(-6, -6, -6, -6),
            BackgroundColor = Color.FromHex("#ff9500")
        };


        OKButton = new Button
        {
            TextColor = Color.White,
            FontSize = 15,
            BorderRadius = 0,
            Text = Localizer.Localize("OK"),
            BackgroundColor = Color.FromHex("#01458e"),
            HorizontalOptions = LayoutOptions.FillAndExpand,
            VerticalOptions = LayoutOptions.FillAndExpand,
            BorderColor = Color.Transparent
        };
        OKButton.Clicked += OKButtonClicked;

        OKStackLayout.Children.Add(OKButton);
        ButtonGrid.Children.Add(OKStackLayout, 3, 0);


        mainGrid.Children.Add(HeaderLabel, 0, 0);

        mainGrid.Children.Add(divider, 0, 1);

        mainGrid.Children.Add(scroll, 0, 2);

        mainGrid.Children.Add(ButtonGrid, 0, 3);



        AbsoluteLayout.SetLayoutFlags(mainGrid, AbsoluteLayoutFlags.All);

        AbsoluteLayout.SetLayoutBounds(mainGrid, Findlayoutbounds(new Rectangle(0.20, 0.25, 0.5, 0.50)));


        _overlay.Children.Add(mainGrid);


        Content = _overlay;
        logservice.WriteData(Constants.DEBUG_LOGGING, "Alert Message Popup ctor.. End");
    }

   // ThreadHandle thread = new ThreadHandle();
    private void CancelButtonClicked(object sender, EventArgs e)
    {
        ButtonValue = false;
        this.IsVisible = false;
       // thread.WorkMethod();
    }

    private void OKButtonClicked(object sender, EventArgs e)
    {

        ButtonValue = true;
        if (PageSource == "StarterPage") ;
        //MessagingCenter.Send(this, "ModifyValBooleanForAlert");
        this.IsVisible = false;

       // thread.WorkMethod();
    }

    Rectangle Findlayoutbounds(Rectangle fractionalRect)
    {
        if (fractionalRect.Width - 1 == 0)
            fractionalRect.Width = 0.99;
        if (fractionalRect.Height - 1 == 0)
            fractionalRect.Height = 0.99;
        Rectangle layoutbounds = new Rectangle
        {
            X = fractionalRect.X / (1 - fractionalRect.Width),
            Y = fractionalRect.Y / (1 - fractionalRect.Height),
            Width = fractionalRect.Width,
            Height = fractionalRect.Height
        };

        return layoutbounds;
    }

    public void DisplayAlertPopup(string alertBoxTitle, string alertBoxContent,bool CancelDisplay)
    {
        HeaderLabel.IsVisible = false;
        CancelStackLayout.IsVisible = CancelDisplay;
        CancelButton.IsVisible = CancelDisplay;
        HeaderLabel.Text = alertBoxTitle;
        MessageLabel.Text = alertBoxContent;
        OKButton.Text = Localizer.Localize("OK");
        CancelButton.Text = Localizer.Localize("CancelSmall");
        HeaderLabel.IsVisible = true;
    }

    public void DisplayAlertPopup(string alertBoxTitle, string alertBoxContent, string ButtonText)
    {
        CancelStackLayout.IsVisible = false;
        CancelButton.IsVisible = false;
        HeaderLabel.Text = alertBoxTitle;
        MessageLabel.Text = alertBoxContent;
        OKButton.Text = ButtonText;
    }

    public void DisplayAlertConditionalPopup(string alertBoxTitle, string alertBoxContent, bool CancelDisplay)
    {
        CancelStackLayout.IsVisible = CancelDisplay;
        CancelButton.IsVisible = CancelDisplay;
        HeaderLabel.Text = alertBoxTitle;
        MessageLabel.Text = alertBoxContent;
        this.IsVisible = true;

    }

    public void SetButtonText(string OKText, string CancelText)
    {
        if (OKText != null)
            OKButton.Text = OKText;
        if (CancelText != null)
            CancelButton.Text = CancelText;
    }

}

I get the formatted string from some other class and call the DisplayAlertPopup method. MessageLabel is the label for which I am setting this value.

Update2:

As suggested in answer, I have tried the below code to set the font for Android. But its also not displying the text in the required format.

MessageLabel = new Label
    {
        FontAttributes = FontAttributes.None,
        FontSize = 13,
        HorizontalTextAlignment = TextAlignment.Start,
        VerticalTextAlignment = TextAlignment.Center,
        HorizontalOptions = LayoutOptions.StartAndExpand,
        TextColor = Color.Black,
        FontFamily = "Droid Sans Mono"
    };

Answer 1

You will need to use a fixed-width font. There is unfortunately none that is built-in across all platforms, but each platform has its own:

• iOS - Courier New
• Android - Droid Sans Mono
• UWP - Consolas

If no built-in font suits you or you want to have the same experience on all platforms, you can also use custom fonts in Xamarin.Forms. This requires you to find a fixed-width font you like on a service like Google Fonts . Then you can follow the tutorial here on Xamarin Help , that describes how to include the TTF file in each platform and use it from XAML.

The short summary is:

1. Add the font to each platform project with appropriate build action (UWP - Content, iOS - Bundle Resource, Android - Android Asset)
2. Use the OnPlatform syntax to set the font (ideally creating a static resource so that it can be reused):

Resource:

<OnPlatform x:TypeArguments="x:String" x:Key="MyFontFamily">
    <On Platform="Android" Value="MyFont.ttf#Open Sans" />
    <On Platform="UWP" Value="/Assets/MyFont.ttf#Open Sans" />
    <On Platform="iOS" Value="MyFont" />
</OnPlatform>

And use like this:

<Label FontFamily="{StaticResource MyFontFamily}" />