Multiple Image Picker in Xamarin IOS

On the click of button

private async void btnOpenGallery(object sender, EventArgs e)
{         
   DependencyService.Get<IMediaService>().GetGMImageStreamAsync();
}
 

Create Interface to open Image Picker

public interface IMediaService
{
      void GetGMImageStreamAsync();
}

In Xamarin.IOS Project implement Interface

public class MediaService: UIViewController, IMediaService
{
	public  void GetGMImageStreamAsync()
	{ 
		GMImagePickerController picker=new GMImagePickerController();
		picker.MediaTypes = new[] { PHAssetMediaType.Image };
		picker.Title = "Add Images";
		picker.CustomDoneButtonTitle = "Add";
		picker.CustomCancelButtonTitle = "Cancel";
		picker.AllowsMultipleSelection = true;
 
		picker.FinishedPickingAssets += (sender, e) => 
		{
			PHImageManager imageManager = new PHImageManager();
			PHImageRequestOptions options = new PHImageRequestOptions();
			options.DeliveryMode = PHImageRequestOptionsDeliveryMode.HighQualityFormat;
			options.ResizeMode = PHImageRequestOptionsResizeMode.Exact;
			options.Synchronous = true;
			options.NetworkAccessAllowed = true;         
			imageManager.RequestImageForAsset(asset,
			new CGSize(asset.PixelWidth, asset.PixelHeight),
			PHImageContentMode.Default,
			null,
			(image, info) => {
 
			 // var data = image.AsJPEG();
			 // byte[] imageData = data.ToArray();
 
			});  
		};
 
		/optional       
		picker.Canceled += Picker_Canceled;
		UIWindow window = UIApplication.SharedApplication.KeyWindow;
		var viewController = window.RootViewController;
		viewController.PresentModalViewController(picker, true);
	}
}

Checkbox in Xamarin IOS and Android

Use Image and set checked and unchecked image to it source dynamically 


Design Side: 

<Image Source="unchecked_checkbox" >
     <Image.GestureRecognizers >
         <TapGestureRecognizer Tapped="TapGestureRecognizerForCheckStaff" />
       </Image.GestureRecognizers>
</Image>

Coding Side:

private void TapGestureRecognizerForCheckStaff(object sender, EventArgs e)

{
 
    Image img = (Image)sender;
    var selectedImage = img.Source as FileImageSource;
 
    if (selectedImage.File == "unchecked_checkbox")
    {
        // perform action checkbox is checked;
        img.Source = "checked_checkbox";
    }
 
    if (selectedImage.File == "checked_checkbox")
    {
        // perform action when checkbox is unchecked
        img.Source = "unchecked_checkbox";
    }
 
}

            

Navigate to specific tab inside master detail page in Xamarin

public App()
{
	  InitializeComponent();
	  var parentPage = new MasterDetailView(); // name of the master detail page
	  parentPage.IsPresented = false;
	  var tabbedPage = new MasterDetailTabbedPage(); // name of the tabbed page
	  tabbedPage.CurrentPage = tabbedPage.Children[2]; // specify the index of the tab 
	  parentPage.Detail = new NavigationPage(tabbedPage); // assign the tabbed page to master detail page
	  MainPage = parentPage; // navigate to master detail page (3rd tab selected)
 }

How to fire tap event of image button in Xamarin

Design Side  

<Image  x:Name="imgThumbnail"  HorizontalOptions="FillAndExpand"   VerticalOptions="FillAndExpand"     Aspect="AspectFill"   >
  <Image.GestureRecognizers >
    <TapGestureRecognizer Tapped="TapGestureRecognizer_Tapped">
    </TapGestureRecognizer>
  </Image.GestureRecognizers>
</Image>

Coding Side

private void TapGestureRecognizer_Tapped(object sender, EventArgs e)
{
          // Handle Event
}