Android Splash活动未显示（Xamarin表单）

Question

My Splash Activity just shows a plain white screen. I am in a Xamarin Forms project. When I tried using a style to set the background, it worked, but the image was stretched out, which is why I am trying to use a LinearLayout and ImageView instead. This is my code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Android.App;
using Android.Content;
using Android.Graphics;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;

namespace Buddy.Droid
{
    [Activity(Label = "HeyBuddy", Icon = "@drawable/icon", Theme = "@style/splashscreen", MainLauncher = true, NoHistory = true)]

    public class SplashActivity : Activity
    {
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);

            // Create your application here
            var imageView = new ImageView(this);
            imageView.SetImageResource(Resource.Drawable.splash_screen);
            var layout = new LinearLayout(this);
            layout.SetBackgroundColor(Color.ParseColor("#0098CC"));
            layout.AddView(imageView);
            SetContentView(layout);

        }
        protected override void OnResume()
        {
            base.OnResume();
            StartActivity(typeof(MainActivity));
        }
    }
}

Answer 1

To programmatically create a Layout with an ImageView :

1. Create a ViewGroup.LayoutParams with its width and height set to MatchParent
2. Assign the layoutparams to your ImageView
3. Assign a ImageView.SetScaleType for how you want to scale your drawable (ie ImageView.ScaleType.FitCenter )

Note: You do not need the LinearLayout, just set the background color of your ImageView

protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);

    var layoutParams = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.MatchParent);

    var imageView = new ImageView(this)
    {
        LayoutParameters = layoutParams
    };
    imageView.SetImageResource(Resource.Drawable.splash_screen);
    imageView.SetScaleType(ImageView.ScaleType.FitCenter);
    imageView.SetBackgroundColor(Color.ParseColor("#0098CC"));

    SetContentView(imageView);
}

protected async override void OnResume()
{
    base.OnResume();
    await Task.Delay(5000); // simulate some background work....
    StartActivity(typeof(MainActivity));
}