Question

我想将相机用于我的xamarin应用程序。

我使用以下代码从相机拍摄照片。

Intent intent = new Intent(MediaStore.ActionImageCapture);
            App._file = new File(App._dir, String.Format("myPhoto.jpg", Guid.NewGuid()));
            intent.PutExtra(MediaStore.ExtraOutput, Android.Net.Uri.FromFile(App._file));
            StartActivityForResult(intent, 0);

此代码适用于Android 6.0版。但是当我在清单xml上使用Android版本7.0时无法正常工作。

请帮帮我......

Answer 1

简答

imageUri = FileProvider.GetUriForFile(this, "YourPackageName", photoFile);
takePictureIntent.AddFlags(ActivityFlags.GrantReadUriPermission);

长答案

示例代码

using System;
using Android.App;
using Android.Content;
using Android.Content.PM;
using Android.OS;
using Android.Provider;
using Android.Runtime;
using Android.Support.V4.Content;
using Android.Util;
using DSP.Core.Client.UILogic;
using Java.IO;
using ReadyApps.Xamarin.Framework.Droid;
using ReadyApps.Xamarin.Framework.Droid.Base;
using ReadyApps.Xamarin.Framework.Droid.Controls;
using ReadyApps.Xamarin.Framework.Droid.Helper;
using static ReadyApps.Xamarin.Framework.Droid.Keys.DroidFramePublicKeys;

namespace DSP.Droid.Activities.Orders
{
    [Activity(Theme = "@style/ActivityDialog")]
    public class ChooseImageActivity : BaseActivity<ChooseImageActivityLogic>
    {
        private static readonly string TAG = typeof(ChooseImageActivity).Name;
        private const int REQUEST_CAMERA = 1001;
        private const int SELECT_FILE = 1002;

        private string currentFilePath;
        private MarshMallowPermission marshMallowPermission;
        private ExtTextView openCamera, selectImage;

        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            SetContentView(Resource.Layout.ChooseImageActivity);
            ((MyApplication)Application.Context).OnActivityCreated(this, null);
            marshMallowPermission = new MarshMallowPermission(this);
            InitView();
        }

        void InitView()
        {
            openCamera  = FindViewById<ExtTextView>(Resource.Id.openCamera);
            selectImage = FindViewById<ExtTextView>(Resource.Id.selectImage);

            openCamera.Click += OpenCamera_Click;
            selectImage.Click +=SelectImage_Click;
        }

        void SelectImage_Click(object sender, EventArgs e)
        {
            if (VersionUtils.isAfter23())
            {
                if (!marshMallowPermission.checkPermissionForReadExternalStorage())
                {
                    marshMallowPermission.requestPermissionForReadExternalStorage();
                }
            }
            DispatchChoosePictureIntent();
        }

        void OpenCamera_Click(object sender, EventArgs e)
        {
            if (VersionUtils.isAfter23())
            {
                if (!marshMallowPermission.checkPermissionForCamera())
                {
                    marshMallowPermission.requestPermissionForCameraAndStorage();
                }
            }
            DispatchTakePictureIntent();
        }

        private void DispatchTakePictureIntent()
        {
            var takePictureIntent = new Intent(MediaStore.ActionImageCapture);
            File photoFile = null;
            Android.Net.Uri imageUri;
            try
            {
                photoFile = FileUtils.createImageFile();
                currentFilePath = "file:" + photoFile.AbsolutePath;
                if (VersionUtils.isAfter24())
                {
                    imageUri = FileProvider.GetUriForFile(this, "YourPackageName", photoFile);
                    takePictureIntent.AddFlags(ActivityFlags.GrantReadUriPermission);
                }
                else { 
                    imageUri = Android.Net.Uri.FromFile(photoFile);
                }

            if (photoFile != null && takePictureIntent.ResolveActivity(PackageManager) != null)
            {
                takePictureIntent.PutExtra(MediaStore.ExtraOutput, imageUri);
                StartActivityForResult(takePictureIntent, REQUEST_CAMERA);
            }
            }
            catch (Exception e)
            {
                Log.Debug(TAG, e.Message);
                return;
            }

        }
        private void DispatchChoosePictureIntent()
        {
            var intent = new Intent(Intent.ActionPick, MediaStore.Images.Media.ExternalContentUri);
            intent.SetType("image/*");
            StartActivityForResult(Intent.CreateChooser(intent, GetString(Resource.String.select_picture)), SELECT_FILE);
        }
        protected override void OnActivityResult(int requestCode, [GeneratedEnum] Result resultCode, Intent data)
        {
            base.OnActivityResult(requestCode, resultCode, data);

            if (resultCode == Result.Ok)
            {
                Intent mIntent = new Intent();
                Android.Net.Uri imageUri = null;
                switch (requestCode) { 
                    case REQUEST_CAMERA:
                         imageUri = Android.Net.Uri.Parse(currentFilePath);
                        break;
                    case SELECT_FILE:
                        imageUri = data.Data;
                        break;
                }
                mIntent.SetData(imageUri);
                SetResult(Result.Ok, mIntent);
                Finish();
            }
        }

        public override void OnRequestPermissionsResult(int requestCode, string[] permissions, Permission[] grantResults)
        {

            if (grantResults?.Length> 0 && grantResults[0] == Permission.Granted)
            {
                switch (requestCode)
                {
                    case CAMERA_Storage_PERMISSION_REQUEST_CODE:
                        {
                            DispatchTakePictureIntent();
                        }
                        break;

                    case READ_EXTERNAL_STORAGE_PERMISSION_REQUEST_CODE:
                        {
                            DispatchChoosePictureIntent();
                        }
                        break;
                }
            }

            base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
        }

        public override void CleanResources()
        {

        }
    }
}

清单

<provider android:name="android.support.v4.content.FileProvider" android:authorities="YourPackageName" android:exported="false" android:grantUriPermissions="true">
            <meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/provider_paths" />
        </provider>

资源 - ＆gt; xml - ＆gt; provider_paths.xml

<?xml version="1.0" encoding="UTF-8" ?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="external_files" path="."/>
</paths>

FileUtils - ＆gt; createImageFile（）

public class FileUtils { public static File createImageFile() { //create an image file name string timeStamp = DateTime.Now.Ticks.ToString(); string imageFileName = "JPEG_" + timeStamp + "_"; File storageDir = Android.OS.Environment.GetExternalStoragePublicDirectory( Android.OS.Environment.DirectoryPictures); if (!storageDir.Exists()) { storageDir.Mkdirs(); } File image = File.CreateTempFile( imageFileName, ".jpg", storageDir ); // Save a file: path for use with ACTION_VIEW intents return image; } }

VersionUtils - ＆gt; isAfter24（）

public static class VersionUtils { public static bool isAfter24() { return Build.VERSION.SdkInt >= BuildVersionCodes.N; } }

你可以忽略MarshMallowPermission

使用xamarin android为Android版7.0拍照

1 个答案: