Question

当用户使用不推荐使用的Actionbar和TabHost重新选择使用Xamarin在Android编码中选择的选项卡时，我正在尝试刷新WebView。

我有此代码

    public void OnTabReselected(WhatsOnActivity tab, FragmentTransaction ft)
    {
        WebView whatsOnWebView = FindViewById<WebView>(Resource.Id.webViewWhatsOn);
        //tell webview to reload
        whatsOnWebView.Reload();
    }

并且我试图将该代码同时放入MainActivity和WhatsOnActivity内部

它不会使应用程序崩溃，但也不会重新加载选项卡。在Xamarin中，我可以使用“ WhatsOnActivity”作为方法中的选项卡吗？我有一种感觉，那就是我做错了..但是，如果我尝试使用选项卡ID，IDE不会识别它们。谁能给我指导我做错了什么？

我的完整代码可以在这里找到：

https://github.com/hexag0d/BitChute_Mobile_Android_a2/blob/2.68/MainActivity.cs

如果您想了解上下文。

Answer 1

更新

尝试在第一个标签上设置OnClicklistener。添加标签后，设置监听器。

 TabHost.TabWidget.GetChildAt(0).SetOnClickListener(new MyOnClickListener(tabHost));

听众：

    public class MyOnClickListener : Java.Lang.Object, IOnClickListener
    {
        TabHost tabHost;
        public MyOnClickListener(TabHost tabHost)
        {
            this.tabHost = tabHost;
        }
        public void OnClick(View v)
        {

            var parentView = ((ViewGroup)((ViewGroup)tabHost.GetChildAt(0)).GetChildAt(1)).GetChildAt(0);
            WebView whatsOnWebView = parentView.FindViewById<WebView>(Resource.Id.webViewWhatsOn);
            whatsOnWebView.Reload();
            tabHost.CurrentTab = 0;
        }
    }

结果是：

原始答案

请尝试将OnTabChangeListener添加到您的TabHost。

例如，在您的MainActivity OnCreate()中：

        TabHost tabHost = FindViewById<TabHost>(Android.Resource.Id.TabHost);
        tabHost.SetOnTabChangedListener(new MyOnTabChangedListener(tabHost));

还有MyOnTabChangedListener：

    public class MyOnTabChangedListener : Java.Lang.Object, IOnTabChangeListener
    {
        TabHost tabHost;
        public MyOnTabChangedListener(TabHost tabHost)
        {
            this.tabHost = tabHost;
        }

        public void OnTabChanged(string tabId)
        {
            if(tabId == "whats_on")
            {
                var parentView = ((ViewGroup)((ViewGroup)tabHost.GetChildAt(0)).GetChildAt(1)).GetChildAt(0);                    
                WebView whatsOnWebView = parentView.FindViewById<WebView>(Resource.Id.webViewWhatsOn);
                whatsOnWebView.Reload();
            }
        }
    }

Answer 2

首先感谢@Billy Liu-MSFT !!!花花公子是救生员。他知道他的Xamarin。好的，这就是您可以刷新标签OnClick的方法

//程序集

using System;
using System.Threading.Tasks;
using Android.App;
using Android.Content;
using Android.Graphics.Drawables;
using Android.OS;
using Android.Widget;
using Android.Webkit;
using static Android.Widget.TabHost;
using static Android.Views.View;
using Android.Views;

//this assembly is your Activities class, which should contain your class instances
using com.xamarin.example.BitChute.Activities;

编辑：将这些单击侦听器放入MainActivity.cs中。GetChildAt（）中的int表示侦听器将响应的选项卡。 int 0 =最左边的制表符，它们上升0 .. 1 .. 2 ..等等.. 1意味着制表符从左数第二。每个侦听器将需要它自己的侦听器类实例。在下一个块中，我将显示两个示例。

        TabHost tabHost = FindViewById<TabHost>(Android.Resource.Id.TabHost);

        tabHost.Setup();

        tabHost.TabWidget.GetChildAt(0).SetOnClickListener(new WhatsOnClickListener(tabHost));

        tabHost.TabWidget.GetChildAt(1).SetOnClickListener(new SubsClickListener(tabHost));

        tabHost.TabWidget.GetChildAt(2).SetOnClickListener(new DiscoverClickListener(tabHost));

        tabHost.TabWidget.GetChildAt(3).SetOnClickListener(new MyChannelClickListener(tabHost));

        tabHost.TabWidget.GetChildAt(4).SetOnClickListener(new SettingsClickListener(tabHost));

编辑：创建一个单独的ClickActivity.cs文件，然后将这些侦听器添加到其中。您将需要为每个标签创建一个OnClickListener实例。这个例子只是两个侦听器。但是如果您使用的是模板，则需要使用以下示例创建另外3个侦听器。

public class WhatsOnClickListener : Java.Lang.Object, IOnClickListener
{
    TabHost tabHost;

    //this int will tell the click listener whether to reload the webview or pop 2 root
    static int tbC = 0;

    public WhatsOnClickListener(TabHost tabHost)
    {
        //tell the clicklistener which tabhost to use
        this.tabHost = tabHost;
    }

    //this class handles the click event
    public void OnClick(View v)
    {

        //declare the webview and tell our object where to find the XAML resource
        WebView webViewWhatsOn = tabHost.CurrentView.FindViewById<WebView>(Resource.Id.webViewWhatsOn);

        //...if the CurrentTab != 0 ... we won't fire the Reload() or LoadUrl() 
        //..without this logic, the app will crash because our WebViews 
        //.aren't set to an instance of an object
        if (tabHost.CurrentTab == 0)
        {
            //if tbC int is 0, we will reload the page
            if (tbC == 0)
            {
                //tell whatsOnWebView to Reload
                webViewWhatsOn.Reload();

                //set the int to one so next time webview will pop to root
                tbC = 1;
            }
            //else if the int is 1, we will pop to root on tab 0
            else if (tbC == 1)
            {
                //tell whatsOnWebView to pop to root
                webViewWhatsOn.LoadUrl(@"https://bitchute.com/");

                //set the tbC int so that next time webview will reload
                tbC = 0;
            }
        }

        //if our current tab isn't zero, we need to set CurrentTab to 0
        //this line is critical or our tabs won't work when not selected
        tabHost.CurrentTab = 0;
    }
}

public class SubsClickListener : Java.Lang.Object, IOnClickListener
{
    TabHost tabHost1;

    static int tbC = 0;

    public SubsClickListener(TabHost tabHost1)
    {
        this.tabHost1 = tabHost1;
    }
    public void OnClick(View v)
    {
        if (tabHost1.CurrentTab == 1)
        {

            WebView subWebView = tabHost1.CurrentView.FindViewById<WebView>(Resource.Id.webViewSubs);

            if (tbC == 0)
            {
                subWebView.Reload();

                tbC = 1;
            }

            else if (tbC == 1)
            {
                subWebView.LoadUrl(@"https://bitchute.com/subscriptions/");

                tbC = 0;
            }
        }

        tabHost1.CurrentTab = 1;
    }
}

希望有帮助！我已经尝试了这一分钟。

XAMARIN：如何刷新WebView OnTabReselected？

2 个答案: