Hi! I have this following code. The problem is that when I put the code outside the ButtonScan method, it works. If I put it inside the method, it doesn't work because it doesn'tt let me click on the button. I'm working with BLE.Plugin.

MainPage.xaml

<StackLayout Padding="10,10,10,10" BackgroundColor="White">
  <Image TranslationY="20" Source="Image.png"/>
  <Button x:Name="btn_scan_device" BorderColor="Black" Text="Scan" TextColor="Green" TranslationY="150" WidthRequest="60"   HeightRequest="50" Clicked="ButtonScan"/>
  <StackLayout x:Name="sl_deviceList">
    <ListView x:Name="lv_deviceList">
      <Label x:Name="lbl_deviceList" />
    </ListView>
  </StackLayout>
</StackLayout>

MainPage.xaml.cs (This Works)

public partial class MainPage : ContentPage
{
    public IDevice device;

    public MainPage()
    {
        InitializeComponent();

        var ble = CrossBluetoothLE.Current;
        var adapter = CrossBluetoothLE.Current.Adapter;

        ble.StateChanged += (s, c) =>
        {
            Debug.WriteLine($"The bluetooth state changed to {c.NewState}");
        };

        adapter.DeviceDiscovered += (s, a) =>
        {
            Debug.WriteLine($"!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!NEW DEVICE FONDUURUUUUUUUU!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! {a.Device.Name}");
        };

        adapter.StartScanningForDevicesAsync();

    }

    public void ButtonScan(object sender, EventArgs e)
    {

    }
}

(This NOT Works)

public partial class MainPage : ContentPage
{
    public IDevice device;

    public MainPage()
    {
        InitializeComponent();

    }

    public void ButtonScan(object sender, EventArgs e)
    {
        var ble = CrossBluetoothLE.Current;
        var adapter = CrossBluetoothLE.Current.Adapter;

        ble.StateChanged += (s, c) =>
        {
            Debug.WriteLine($"The bluetooth state changed to {c.NewState}");
        };

        adapter.DeviceDiscovered += (s, a) =>
        {
            Debug.WriteLine($"!!!!!!!!!!!!!!!!!!!!!!!!!!NEW DEVICE FONDUURUUUUUUUU!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! {a.Device.Name}");
        };

        adapter.StartScanningForDevicesAsync();
    }
}

Good day. I've met something strange when working with StreamReader and Label.Text. Used WorkingWithFilesPLC sample from GIT and put in StreamReader text file about 5000 symbols (5600 with spaces). When I work with PC, all text is loaded. But when I start debugging at Android device, only about half of a text is load. In MSDN it's said, that Text field uses type string, so its size should be 2 GB or about 1 billion symbols in Windows. But how about Android and IOS? What can the problem be? Can it be, that the length of a string depends of device? Or there are some other reasons, why I can't load whole text file?

Hi,
After updating the Java SDK 8 and updating Tools from Android SDK Manager, i am getting below issue. Kindly guide to resolve this issue.

Javax.Net.Ssl.SSLHandshakeException: SSL handshake aborted: ssl=0x79f1b298: I/O error during system call, Connection reset by peer
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/3540/1cf254db/source/mono/external/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /Users/builder/data/lanes/3540/1cf254db/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /Users/builder/data/lanes/3540/1cf254db/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /Users/builder/data/lanes/3540/1cf254db/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
at System.Runtime.CompilerServices.ConfiguredTaskAwaitable

1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /Users/builder/data/lanes/3540/1cf254db/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535
  at ModernHttpClient.NativeMessageHandler+<SendAsync>c__async0.MoveNext () [0x002f1] in /Users/paul/code/paulcbetts/modernhttpclient/src/ModernHttpClient/Android/OkHttpNetworkHandler.cs:121
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/3540/1cf254db/source/mono/external/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /Users/builder/data/lanes/3540/1cf254db/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /Users/builder/data/lanes/3540/1cf254db/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /Users/builder/data/lanes/3540/1cf254db/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable

--- End of managed Javax.Net.Ssl.SSLHandshakeException stack trace ---
javax.net.ssl.SSLHandshakeException: SSL handshake aborted: ssl=0x79f1b298: I/O error during system call, Connection reset by peer
at com.android.org.conscrypt.NativeCrypto.SSL_do_handshake(Native Method)
at com.android.org.conscrypt.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:318)
at com.squareup.okhttp.Connection.upgradeToTls(Connection.java:242)
at com.squareup.okhttp.Connection.connect(Connection.java:159)
at com.squareup.okhttp.Connection.connectAndSetOwner(Connection.java:175)
at com.squareup.okhttp.OkHttpClient$1.connectAndSetOwner(OkHttpClient.java:120)
at com.squareup.okhttp.internal.http.HttpEngine.nextConnection(HttpEngine.java:330)
at com.squareup.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:319)
at com.squareup.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:241)
at com.squareup.okhttp.Call.getResponse(Call.java:271)
at com.squareup.okhttp.Call$ApplicationInterceptorChain.proceed(Call.java:228)
at com.squareup.okhttp.Call.getResponseWithInterceptorChain(Call.java:199)
at com.squareup.okhttp.Call.access$100(Call.java:34)
at com.squareup.okhttp.Call$AsyncCall.execute(Call.java:162)
at com.squareup.okhttp.internal.NamedRunnable.run(NamedRunnable.java:33)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
}

I work with XamarinForms and has some issues with Entry in ScrollView on Android platform. Autoscroll doesn't work correctly when I focuse on an entry placed in ScrollView. Entry appears above the keyboard but the whole page becomes unscrollable (I can't scroll completely to bottom or top of page). I try to set WindowSoftInputMode to adjustPan or adjustResize or both, and I try different ways to set it (in code, by attribute, directly in AndroidManifest.xml). But any case doesn't work (in each cases behavior remain the same). Please, maybe someone have encountered the same problem and I hope can help me. Thanks a lot.

here it is in Android application i want to implement an odometer in xamarin forms for both android and ios can anyone help me with this..please?
(in the toolbar left side Label is the odometer and the right side label is the timer).

Is there a possibility to share code not only cross plattform, but also between several applications?
For example if I create a specific style with xaml that I want to reuse in other applications in the future.

I have an app that requires both a slide out menu that is accessible from every view, and a back button (in a subheader bar) on every view that was not accessed bu the menu. It should look like the image below.
To get the menu working properly, I created a NavigationPage with the root page the MasterDetail page containing the Menu as the Master and the View as the Detail. When a menu item is clicked, I change the detail page to the appropriate view, and this works well (except that there is no icon in iOS)
Now I am trying to get the 'back' navigation working, but I'm finding that I can't use Navigation because the Detail Page is not a NavigationPage and I can't make it a NavigationPage because I already have a NavigationPage. What I think I need to do is to create a NavigationStack that is not tied to a NavigationPage that I can tie to my back button, but I haven't found a way to do this. Is this possible, or is there a better approach?

I use the light theme as suggest here https://developer.xamarin.com/guides/xamarin-forms/themes/#builtin
Below code in Androdi works fine boxview is circle but it doesnt work on uwp. Does anybody know why and how to make it work?

I've got a bindable string that's populated with HTML.

    public string Description
    {
        get { return _description; }
        set
        {
            _description = value;
            OnPropertyChanged();
        }
    }

Now I'd like that string to be bound to a webview

  <WebView Source="{Binding Description}" VerticalOptions ="FillAndExpand"/>

but this isn't working. Unfortunately the Docs for WebViewSource hasn't been entered yet.

How can I bind a string of HTML to a WebView?

Hi
Consider scenario.
I opened some page, lets call it WaitingPage. There is done some communication in background - application is checking server status. After receving some specific data from server I need to do some background work and finally close WaitingPage and return to previous one. What should I do to close this page? Background work is done by android service. Service has no knowledge about status of interface.

What is the best approach?

I'm struggeling with a simple thing.

How can I display a prompt in a dialog box, thats waits for the user to input text or click a button, and then returns a string containing the contents of the text box with Xamarin.Forms?

With Android or WP8 I was able to create a popup with some controls, but I didn't find any similar in Xamarin.Forms.

Thx, Tom

Good morning guys,
I'm using Iconize FontAwesome in a solution Xamarin Forms and ocurred a error when debug o project IOS. It's returned a message:

Value cannot be null
Parameter: Value

My AppDelegate.cs:

public partial class AppDelegate : XLabs.Forms.XFormsApplicationDelegate
{
public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
Plugin.Iconize.Iconize.With(new FontAwesomeModule());

        global::Xamarin.Forms.Forms.Init();
        if(!Resolver.IsSet)
            SetIoc();

        FormsPlugin.Iconize.iOS.IconControls.Init();
        LoadApplication(new App());
        return base.FinishedLaunching(app, options);
    }

    private void SetIoc()
    {
        var resolverContainer = new SimpleContainer();
        Resolver.SetResolver(resolverContainer.GetResolver());
    }

}

And in XAML:

// iconize:IconLabel Text="fa-map-marker" TextColor="#976E56" Style="{StaticResource IconMenu}"

Already added the key and the array in info.plist.
Thank you.

Hi developers,

i want to get audio record from user and post it to web service. My web service accepts file data type and i already posted media file(image and video) to there.

My app can record audio for iOS and Android but i can not post audio record. To achieve audio recording i have used dependency injection and followed these pages:
https://developer.xamarin.com/recipes/android/media/audio/record_audio/ and
https://developer.xamarin.com/recipes/ios/media/sound/record_sound/

Now, i need to post these recorded audio to web service for each platform.

any help will be appreciated,

thanks a lot

Hi all,
I've got a ListView with a swipe-to-remove button in my ViewCell, using following XAML:

<ViewCell.ContextActions>
<MenuItem Text="Remove" IsDestructive="true" Command="{Binding Delete}"></MenuItem>
</ViewCell.ContextActions>

I got this code from http://developer.xamarin.com/guides/cross-platform/xamarin-forms/working-with/listview/

When tapping the Remove button, the cell item is removed from the ListView's ItemsSource and as a result the row is removed correctly from the table.
However, once the row is gone, the remove button of the row below it is shown (as if the user has also swiped on that row).

Has anyone seen the same behavior?

thanks,
Thomas

I have use the Xamarin Control SignaturePad Form in my PCL project. The code as below:

    public class DigitalSignature : ContentPage
     {
            SignaturePadView sign = new SignaturePadView();

            public DigitalSignature()
            {
                Button btnOk = new Button
                {
                    Text = "Ok",
                    BackgroundColor = Color.FromHex("#ff6600"),
                    HorizontalOptions = LayoutOptions.End,
                    WidthRequest = 100,
                    HeightRequest = 35,
                    FontSize = 15
                };

                btnOk.Clicked += btnOk_Clicked;

                sign = new SignaturePadView()
                {
                    SignatureLineColor = Color.Red,
                    StrokeColor = Color.Black,
                    StrokeWidth = 10f,
                    HeightRequest = 150,
                    BackgroundColor = Color.White,
                    ClearText = "Clear Me"
                };
                sign.CaptionText = "pls sign here";


                Content = new StackLayout
                {
                    Children = {
                        sign,
                        btnOk
                    }
                };

            }

            private void btnOk_Clicked(object sender, EventArgs e)
            {

            }
        }

How I can get the signature as image and store in the database? In the signaturepadview do not has the getImage() function. Anyone has idea how I can do that?

Thanks,
Derick

Hi @all!

I´m using a TabbedPage within a NavigationPage:

        EditReportPage editReportPage = new EditReportPage();
        NavigationPage editPage = new NavigationPage(editReportPage)
        {
            BarBackgroundColor = Color.FromHex("3498DB"),
            BarTextColor = Color.White
        };
        await Navigation.PushModalAsync(editPage);

The NavigationBar has the correct color (blue) and the Text is white. But the Secondary ToolbarItems are gray in Background and white for the Text color.
How can i set the background color for the secondary ToolbarItems?

Thanks for any help!
Greetings

Thomas

If I put an Image made from a MemoryStream in a StackLayout called stack, then when leaving the page the Image gets destructed, but not the MemoryStream.

How do I fix this?

My code:

public class LoggingMemoryStream : MemoryStream
{
    public LoggingMemoryStream(byte[] arg) : base(arg)
    {
        Debug.WriteLine("LoggingMemoryStream");
    }

    ~LoggingMemoryStream()
    {
        Debug.WriteLine("~LoggingMemoryStream");
    }
}

public class LoggingImage : Image
{
    public LoggingImage()
    {
        Debug.WriteLine("LoggingImage");
    }

    ~LoggingImage()
    {
        Debug.WriteLine("~LoggingImage");
    }
}

var enc = "R0lGODlhPQBEAPeoAJosM//AwO/AwHVYZ/z595kzAP/s7P+goOXMv8+fhw/v739/f+8PD98fH/8mJl+fn/9ZWb8/PzWlwv///6wWGbImAPgTEMImIN9gUFCEm/gDALULDN8PAD6atYdCTX9gUNKlj8wZAKUsAOzZz+UMAOsJAP/Z2ccMDA8PD/95eX5NWvsJCOVNQPtfX/8zM8+QePLl38MGBr8JCP+zs9myn/8GBqwpAP/GxgwJCPny78lzYLgjAJ8vAP9fX/+MjMUcAN8zM/9wcM8ZGcATEL+QePdZWf/29uc/P9cmJu9MTDImIN+/r7+/vz8/P8VNQGNugV8AAF9fX8swMNgTAFlDOICAgPNSUnNWSMQ5MBAQEJE3QPIGAM9AQMqGcG9vb6MhJsEdGM8vLx8fH98AANIWAMuQeL8fABkTEPPQ0OM5OSYdGFl5jo+Pj/+pqcsTE78wMFNGQLYmID4dGPvd3UBAQJmTkP+8vH9QUK+vr8ZWSHpzcJMmILdwcLOGcHRQUHxwcK9PT9DQ0O/v70w5MLypoG8wKOuwsP/g4P/Q0IcwKEswKMl8aJ9fX2xjdOtGRs/Pz+Dg4GImIP8gIH0sKEAwKKmTiKZ8aB/f39Wsl+LFt8dgUE9PT5x5aHBwcP+AgP+WltdgYMyZfyywz78AAAAAAAD///8AAP9mZv///wAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACH5BAEAAKgALAAAAAA9AEQAAAj/AFEJHEiwoMGDCBMqXMiwocAbBww4nEhxoYkUpzJGrMixogkfGUNqlNixJEIDB0SqHGmyJSojM1bKZOmyop0gM3Oe2liTISKMOoPy7GnwY9CjIYcSRYm0aVKSLmE6nfq05QycVLPuhDrxBlCtYJUqNAq2bNWEBj6ZXRuyxZyDRtqwnXvkhACDV+euTeJm1Ki7A73qNWtFiF+/gA95Gly2CJLDhwEHMOUAAuOpLYDEgBxZ4GRTlC1fDnpkM+fOqD6DDj1aZpITp0dtGCDhr+fVuCu3zlg49ijaokTZTo27uG7Gjn2P+hI8+PDPERoUB318bWbfAJ5sUNFcuGRTYUqV/3ogfXp1rWlMc6awJjiAAd2fm4ogXjz56aypOoIde4OE5u/F9x199dlXnnGiHZWEYbGpsAEA3QXYnHwEFliKAgswgJ8LPeiUXGwedCAKABACCN+EA1pYIIYaFlcDhytd51sGAJbo3onOpajiihlO92KHGaUXGwWjUBChjSPiWJuOO/LYIm4v1tXfE6J4gCSJEZ7YgRYUNrkji9P55sF/ogxw5ZkSqIDaZBV6aSGYq/lGZplndkckZ98xoICbTcIJGQAZcNmdmUc210hs35nCyJ58fgmIKX5RQGOZowxaZwYA+JaoKQwswGijBV4C6SiTUmpphMspJx9unX4KaimjDv9aaXOEBteBqmuuxgEHoLX6Kqx+yXqqBANsgCtit4FWQAEkrNbpq7HSOmtwag5w57GrmlJBASEU18ADjUYb3ADTinIttsgSB1oJFfA63bduimuqKB1keqwUhoCSK374wbujvOSu4QG6UvxBRydcpKsav++Ca6G8A6Pr1x2kVMyHwsVxUALDq/krnrhPSOzXG1lUTIoffqGR7Goi2MAxbv6O2kEG56I7CSlRsEFKFVyovDJoIRTg7sugNRDGqCJzJgcKE0ywc0ELm6KBCCJo8DIPFeCWNGcyqNFE06ToAfV0HBRgxsvLThHn1oddQMrXj5DyAQgjEHSAJMWZwS3HPxT/QMbabI/iBCliMLEJKX2EEkomBAUCxRi42VDADxyTYDVogV+wSChqmKxEKCDAYFDFj4OmwbY7bDGdBhtrnTQYOigeChUmc1K3QTnAUfEgGFgAWt88hKA6aCRIXhxnQ1yg3BCayK44EWdkUQcBByEQChFXfCB776aQsG0BIlQgQgE8qO26X1h8cEUep8ngRBnOy74E9QgRgEAC8SvOfQkh7FDBDmS43PmGoIiKUUEGkMEC/PJHgxw0xH74yx/3XnaYRJgMB8obxQW6kL9QYEJ0FIFgByfIL7/IQAlvQwEpnAC7DtLNJCKUoO/w45c44GwCXiAFB/OXAATQryUxdN4LfFiwgjCNYg+kYMIEFkCKDs6PKAIJouyGWMS1FSKJOMRB/BoIxYJIUXFUxNwoIkEKPAgCBZSQHQ1A2EWDfDEUVLyADj5AChSIQW6gu10bE/JG2VnCZGfo4R4d0sdQoBAHhPjhIB94v/wRoRKQWGRHgrhGSQJxCS+0pCZbEhAAOw==";
var arg = System.Convert.FromBase64String(enc);
var ms = new LoggingMemoryStream(arg);
var img = new LoggingImage();
var src = ImageSource.FromStream(() => ms);
img.Source = src;
stack.Children.Add(img);

I'm creating a cross-platform app. When i click on the button to go to the location page where i render a map i encountered the next error:

Xamarin.Forms.Platform.Android.ViewRenderer`2.CreateNativeControl' not found.

Anyone have a solution?

When placing multiple Entry controls on a page in Xamarin forms, there appears to be no (obvious) way to enable the Next/Finished buttons that appear on the device keyboard. The buttons appear, but clicking them does nothing.

You can replicate this in the 'FormsSample' app on the 'Entry (single line)' page. The next button appears on the email and password fields, and the finished button on the phone number field, but none of the do anything.

Am I missing something obvious or is this a bug/feature omission?

Thanks

If I have a page the has a binding context, but I want to grab some of those values from the binding context in the code behind, how would I go about doing that?