For Loop and SkiaSharp

Question

Hi,
How can I use for in SkiaSharp,
Let's say I want to show every word for 10 seconds (600 frames).

It sounds simple, but I haven't figured it out today.

for code

string[] numbers = { "one", "two", "three", "four",  "five"};
foreach (string i in numbers)
{
    text = i;
}

SkiaSharp code

using SkiaSharp;
using System;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;

namespace MyApp1
{
    [XamlCompilation(XamlCompilationOptions.Compile)]
    public partial class Page1 : ContentPage
    {
        string text = "";

        public Page1()
        {
            InitializeComponent();

             Device.StartTimer(TimeSpan.FromSeconds(1f / 60), () =>
            {
                canvasView.InvalidateSurface();
                return true;
            });

         }

        private void canvas_PaintSurface(object sender, SkiaSharp.Views.Forms.SKPaintSurfaceEventArgs e)
        {

            SKSurface surface = e.Surface;
            SKCanvas canvas = surface.Canvas;

            int width = e.Info.Width;
            int height = e.Info.Height;

            canvas.Clear();  

            SKPaint textPaint = new SKPaint();
            textPaint.Color = SKColors.MidnightBlue;
            textPaint.TextSize = 30;
            canvas.DrawText(text, width / 2, height / 2, textPaint);
        }
    }
}

Thank you in advance.

Answer 1

use the timer:

Action doLoop<int> = (count) =>
{            
   if (count >= numbers.Length)
        return;
   text = numbers[count];
   Device.StartTimer(TimeSpan.FromSeconds(1f / 60), () =>
   {
          canvasView.InvalidateSurface();
          doLoop(--count); 
         return true;
   });
}
doLoop();

Answer 2

Hello,

For this problem, you can use nested function to achieve this .

I used a Label to simulate this functionality and loop through the array.

You can refer to my code:

public partial class MainPage : ContentPage  
{  
    string[] numbers = { "one", "two", "three", "four", "five" };  
  
    string text = "one";  
  
  
    public MainPage()  
    {  
        InitializeComponent();  
    }  
  
    private void Button_Clicked(object sender, EventArgs e)  
    {  
        MyLoop(0);  
    }  
  
  
    public void MyLoop(int count)   
    {  
        if (count >= numbers.Length) {  
            count = 0;  
        }  
  
        text = numbers[count];  
  
        Device.StartTimer(TimeSpan.FromMilliseconds(10000), () =>  
        {  
  
            mLabel.Text = text;  
  
            MyLoop(++count);  
            return false;  
        });  
    }  
}  

Note:

When the last element of the data is traversed, the first element is traversed again.

 if (count >= numbers.Length) {  
                count = 0;  
            }  

Best Regards,
Jessie Zhang

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