How to Capture multiple photos with Camera xamarin Forms android

问题

I am developing Xamrin form application. Inside it, I am trying to capture multiple photos using a camera with the same intent. without using any nuget package?

for this, I am following this link Camera

MainActivity.cs

static readonly File file = new File(Environment.GetExternalStoragePublicDirectory(
                                Environment.DirectoryPictures), "tmp.jpg");

At the end of OnCreate

(Xamarin.Forms.Application.Current as App).ShouldTakePicture += () => {
    var intent = new Intent(MediaStore.ActionImageCapture);
    intent.PutExtra(MediaStore.ExtraOutput, Uri.FromFile(file));
    StartActivityForResult(intent, 0);
};

here I am getting only 1 photo on clicking camera button but I want to capture more photo and I want its file path

in OnActivityResult

(Xamarin.Forms.Application.Current as App).ShowImage(file.Path);

but maybe it has few limitations such as we can not capture multiple photos at a time? Is anyone is having an idea how to capture multiple photos and bind it to listview?

回答1:

Yes after so much struggle I am able to do this. It may be helpful for someone who is working on such things in xamarin forms.

This is my code

 public partial class App : Application
    {
       // public static App Instance;

        public App ()
        {
            MainPage = new CameraGallery.MainPage();
            InitializeComponent();
        }
    }

MainPage.xaml

// please install FlowListView and ffimageloading nuget pckg

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:CameraGallery"
             x:Class="CameraGallery.MainPage"
             xmlns:flv="clr-namespace:DLToolkit.Forms.Controls;assembly=DLToolkit.Forms.Controls.FlowListView"
             xmlns:ffimageloading="clr-namespace:FFImageLoading.Forms;assembly=FFImageLoading.Forms"> 

            <StackLayout x:Name="CameraLayout">
                <flv:FlowListView FlowColumnCount="3" x:Name="listItemsCam" 
                        SeparatorVisibility="None"
                        HasUnevenRows="false" RowHeight="100" >
                    <flv:FlowListView.FlowColumnTemplate>
                        <DataTemplate >
                            <ffimageloading:CachedImage  DownsampleToViewSize="true" AbsoluteLayout.LayoutFlags="All" HeightRequest="100" AbsoluteLayout.LayoutBounds="0,0,1,1" Source="{Binding .}"  Aspect="AspectFill" HorizontalOptions="FillAndExpand">
                            </ffimageloading:CachedImage>
                        </DataTemplate>
                    </flv:FlowListView.FlowColumnTemplate>
                </flv:FlowListView>
                <!--<Image x:Name="image" IsVisible="False"></Image>-->
            </StackLayout>
</ContentPage>  

MainPage.xaml.cs

 public partial class MainPage : ContentPage
        {
            ObservableCollection<string> camImageCollection;
            public static MainPage Instance;

            public MainPage()
            {
                InitializeComponent();
                Instance = this;

                var btn = new Button
                {
                    Text = "Snap!",
                    Command = new Command(o => ShouldTakePicture()),
                };
                CameraLayout.Children.Add(btn);  

                camImageCollection = new ObservableCollection<string>();
            }
            public event Action ShouldTakePicture = () => { };

            public void ShowImage(string[] filepath)
            {
               foreach(var item in filepath)
                 camImageCollection.Add(item);
                 listItemsCam.FlowItemsSource = camImageCollection;
            }
        }

now go to your android project inside it MainActivity.cs

[Activity(Label = "CameraGallery", Icon = "@drawable/icon", Theme = "@style/MainTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
    {
        public static int OPENCAMERACODE = 102;
        //inside OnCreate after LoadApplication(new App()); add these lines
         protected override void OnCreate(Bundle bundle)
        {
            TabLayoutResource = Resource.Layout.Tabbar;
            ToolbarResource = Resource.Layout.Toolbar;
            UserDialogs.Init(this);
            base.OnCreate(bundle);

            global::Xamarin.Forms.Forms.Init(this, bundle);

            FlowListView.Init();
            CachedImageRenderer.Init(false);
            LoadApplication(new App());
            MainPage.Instance.ShouldTakePicture += () =>
            {
                ICursor cursor = loadCursor();
                image_count_before = cursor.Count;
                cursor.Close();
                Intent intent = new Intent(MediaStore.IntentActionStillImageCamera);
                IList<ResolveInfo> activities = PackageManager.QueryIntentActivities(intent, 0);
                if(activities.Count >0)
                    StartActivityForResult(Intent.CreateChooser(intent, "Camera Capture"), OPENCAMERACODE);
            };
        }
        public ICursor loadCursor()
        {
            string[] columns = new string[] { MediaStore.Images.ImageColumns.Data, MediaStore.Images.ImageColumns.Id };
            string orderBy = MediaStore.Images.ImageColumns.DateAdded;
            return ContentResolver.Query(MediaStore.Images.Media.ExternalContentUri, columns, null, null, orderBy);
        }
        private void exitingCamera()
        {
            ICursor cursor = loadCursor();
            string[] paths = getImagePaths(cursor, image_count_before);
            MainPage.Instance.ShowImage(paths);// this parameter pass to MainPage.xaml.cs
            cursor.Close();
        }
        public string[] getImagePaths(ICursor cursor, int startPosition)
        {
            int size = cursor.Count - startPosition;
            if (size <= 0) return null;
            string[] paths = new string[size];

            int dataColumnIndex = cursor.GetColumnIndex(MediaStore.Images.ImageColumns.Data);
            for (int i = startPosition; i < cursor.Count; i++)
            {
                cursor.MoveToPosition(i);

                paths[i - startPosition] = cursor.GetString(dataColumnIndex);
            }
            return paths;
        }
        //inside OnActivityResult method do this
        protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
        {
            base.OnActivityResult(requestCode, resultCode, data);
            switch (requestCode)
            {
                case 102:
                        exitingCamera();
                    break;
            }
        }
    }   

I hope this help someone. enjoy coding...

来源：https://stackoverflow.com/questions/50506008/how-to-capture-multiple-photos-with-camera-xamarin-forms-android