Xamarin.Forms——上传图片

效果图

1. 在所有平台增加Plugin.Media NutGet包
   
   
   1. 编写xaml
      


      3.处理事件

 private async void Button_Clicked(object sender, EventArgs e)
        {
            string imgName= await TakeImageAction("123");
        }

4.编写TakeImageAction()方法

    string action = await DisplayActionSheet("", "", "", "拍照", "从相册选择");
            MediaFile pickFile = null;
            switch (action)
            {
                case "拍照":
                    //判断能否使用摄像头
                    if (!CrossMedia.Current.IsCameraAvailable || !CrossMedia.Current.IsTakePhotoSupported)
                    {
                        await DisplayAlert("错误提示", "未找到可用摄像头", "确认");
                    }

                    var filea = await CrossMedia.Current.TakePhotoAsync(new Plugin.Media.Abstractions.StoreCameraMediaOptions
                    {
                        PhotoSize = Plugin.Media.Abstractions.PhotoSize.Medium,
                        //拍照后的文件夹名
                        Directory = "SjBIdrPics",
                        //拍照后的文件名
                        Name = "SjBIdr.jpg"
                    });

                    if (filea == null)
                        return null;

                    pickFile = filea;

                    break;
                case "从相册选择":
                    //判断能否读取图片
                    if (!CrossMedia.Current.IsPickPhotoSupported)
                    {
                        await DisplayAlert("错误提示", "未获得权限读取相册", "确认");
                    }

                    //选择图片
                    var fileb = await Plugin.Media.CrossMedia.Current.PickPhotoAsync(new Plugin.Media.Abstractions.PickMediaOptions
                    {
                        PhotoSize = Plugin.Media.Abstractions.PhotoSize.Medium
                    });
                    if (fileb == null)
                        return null;
                    pickFile = fileb;
                    break;
            }        
            if (pickFile != null)
            {
                //上传图片到服务器
                HttpClient client = new HttpClient();
                #region
                MultipartFormDataContent form = new MultipartFormDataContent();
                StreamContent fileContent = new StreamContent(pickFile.GetStream());
                fileContent.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
                fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data");
                fileContent.Headers.ContentDisposition.FileName = System.DateTime.Now.ToString("yyyMMddHHmmss") + "_" + UserName + ".jpg";
                form.Add(fileContent);
                #endregion
                HttpResponseMessage res = await client.PostAsync("***/Test/ImageUpload", form);
                var uploadModel = await res.Content.ReadAsStringAsync();
                return uploadModel;
                }
            else
            {
                return "";
            }

GitHub官方文档:https://github.com/jamesmontemagno/MediaPlugin