为布局屏幕加载图标xamarin android

Question

我想知道如何在处理发生处理时如何将加载GIF加载到Android布局时有任何好的想法/教程，并且页面布局导航到另一个页面布局时。

我已经尝试过这个 - adhud

但它似乎与PCL内部的门户类库（PCL）和PCL内的服务不太好。我找不到这个组件的很多例子。

我看到Android使用进度对话框，但我希望在C＃中的Xamarin版本或任何其他聪明的方式。

Answer 1

为android项目添加 andhud 以及 btprogresshud 到您的iOS项目。

然后，您只需要在PCL中创建一个接口，如下所示：

public enum MaskType
{
    None = 1,
    Clear,
    Black,
    Gradient
}

public interface IHudService
{
    void Show(string message, MaskType maskType, int progress = -1);
    void Dismiss();
    void ShowToast(string message, bool showToastCentered = true, double timeoutMs = 1000);
    void ShowToast(string message, MaskType maskType, bool showToastCentered = true, double timeoutMs = 1000);
}

.

和每个项目中的具体实现（iOS示例）：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using BigTed;
using Foundation;
using MyExample.Services;
using UIKit;

[assembly: Xamarin.Forms.Dependency(typeof(MyExample.iOS.Services.HudService))]

namespace MyExample.iOS.Services
{
    public class HudService : IHudService
    {
        public HudService()
        {
        }

        #region IHudService Members

        public void Show(string message, MaskType maskType, int progress)
        {
            float p = (float)progress / 100f;
            BTProgressHUD.Show(message, p, (ProgressHUD.MaskType)maskType);
        }

        public void Dismiss()
        {
            BTProgressHUD.Dismiss();
        }

        public void ShowToast(string message, bool showToastCentered = true, double timeoutMs = 1000)
        {
            BTProgressHUD.ShowToast(message, showToastCentered, timeoutMs);
        }

        public void ShowToast(string message, MaskType maskType, bool showToastCentered = true, double timeoutMs = 1000)
        {
            BTProgressHUD.ShowToast(message, (ProgressHUD.MaskType)maskType, showToastCentered, timeoutMs);
        }

        #endregion
    }
}

.

，在Android：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using AndroidHUD;
using MyExample.Services;
using Xamarin.Forms;
using XHUD;

[assembly: Xamarin.Forms.Dependency(typeof(MyExample.Android.Services.HudService))]

namespace MyExample.Android.Services
{
    public class HudService : IHudService
    {
            //Although, not well documented, for Xamarin.Forms, "Forms.Context" is the current activity

        public HudService()
        {
        }

        #region IHudService Members

        public void Show(string message, MyExample.Services.MaskType maskType, int progress)
        {
            AndHUD.Shared.Show(Forms.Context, message, progress, (AndroidHUD.MaskType)maskType);
        }

        public void Dismiss()
        {
            AndHUD.Shared.Dismiss(Forms.Context);
        }

        public void ShowToast(string message, bool showToastCentered = true, double timeoutMs = 1000)
        {
            AndHUD.Shared.ShowToast(Forms.Context, message, (AndroidHUD.MaskType)MyExample.Services.MaskType.Black, TimeSpan.FromSeconds(timeoutMs / 1000), showToastCentered);
        }

        public void ShowToast(string message, MyExample.Services.MaskType maskType, bool showToastCentered = true, double timeoutMs = 1000)
        {
            AndHUD.Shared.ShowToast(Forms.Context, message, (AndroidHUD.MaskType)maskType, TimeSpan.FromSeconds(timeoutMs / 1000), showToastCentered);
        }

        #endregion
    }

}

.

这基本上只是xhud.hud facade的副本，它被添加到两个库中以平滑API差异。

然后，在特定于平台的项目的入口点（在此情况下，appdelegate.cs）并从pcl调用它，在其服务中注册您的服务。在我的情况下，我正在使用xamarin.forms.labs，因此您的注册方法可能会有所不同。

public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
    SetupIocContainer();
    Forms.Init();
    FormsMaps.Init();
    window = new UIWindow(UIScreen.MainScreen.Bounds);
    window.RootViewController = App.GetMainPage().CreateViewController();
    window.MakeKeyAndVisible();
    return true;
}

private void SetupIocContainer()
{
    var resolverContainer = new SimpleContainer();
    var app = new XFormsAppiOS();
    app.Init(this);

    resolverContainer.Register<IDevice>(t => AppleDevice.CurrentDevice)
        .Register<IDisplay>(t => t.Resolve<IDevice>().Display)

        //EDIT: this does not seem necessary after all and actually
        //causes it to crash on Android (but works on iOS) 
        //not sure why
        //.Register<IHudService>(t => t.Resolve<IHudService>())

        .Register<IXFormsApp>(app)
        .Register<IDependencyContainer>(t => resolverContainer);

    Resolver.SetResolver(resolverContainer.GetResolver());
}

.

在PCL中，您可以确定它并做这样的事情：

private IHudService hudService;
public IHudService HudService
{
    get
    {
        if(hudService == null)
        {
            hudService = DependencyService.Get<IHudService>();
        }
        return this.hudService;
    }
}


private async Task Setup()
{
    this.HudService.Show("Long operation occurring", MaskType.Black);

    await Operation();

    this.HudService.Dismiss();
}

.