在ViewModel问题中绑定到对象属性

Question

不知道为什么这不起作用...下面是设置为View DataContext的ViewModel。

public class UploadViewModel : CrudVMBase
    {
        #region Commands
        public CommandVM UploadButtonCommand { get; set; } =
            new CommandVM
            {
                CommandDisplay = "Perform Upload",
                IconGeometry = App.Current.Resources["pencil30"] as Geometry,
                Message = new CommandMessage { Command = CommandType.UploadFromCamera }
            };
        #endregion End Commands

        #region Public Properties
        UploadInitiation UploadObject { get; set; } = new UploadInitiation();
        #endregion End Public Properties

        public UploadViewModel()
        {

        }

下面是UploadInitiation类

public class UploadInitiation : Common.NotifyUIBase
    {
        #region Public Properties
            public ObservableCollection<UploadStep> Steps { get; set; } = new ObservableCollection<UploadStep>();
            public int UploadProgress { get; set; } = 45;
            public string UploadTask { get; set; } = "Idle...";
            public bool UploadEnabled { get; set; } = false;
            public bool UploadBegin { get; set; } = false;
        #endregion END Public Properties

        public UploadInitiation()
        {
            // Populate steps required, ensure upload returns UI updates
            Steps.Add(new UploadStep { Message = "Seperate upload to new thread...", Complete = false, Error = null });
            Steps.Add(new UploadStep { Message = "Generate new file names...", Complete = false, Error = null });
            Steps.Add(new UploadStep { Message = "Render Thumbnails, add to database...", Complete = false, Error = null });
            Steps.Add(new UploadStep { Message = "Move images ready for print...", Complete = false, Error = null });
        }
    }

这是我的绑定，如您所见，我正在尝试绑定到UploadProgress属性。

<ProgressBar Style="{StaticResource CircularProgress}" Width="180" Value="{Binding UploadObject.UploadProgress}" />

这是错误

System.Windows.Data错误：40：BindingExpression路径错误：在“对象”“ UploadViewModel”（HashCode = 33902366）“上找不到“ UploadObject”属性。 BindingExpression：Path = UploadObject.UploadProgress; DataItem ='UploadViewModel'（HashCode = 33902366）; 目标元素是'ProgressBar'（Name =''）; 目标属性为“值”（类型为“双精度”）

Answer 1

您需要将属性的范围声明为public ，否则默认为私有。 因此，绑定时不可见。

public UploadInitiation UploadObject { get; set; } = new UploadInitiation();