Question

我正在启动WPF项目。试图通过viewmodel绑定usercontrol。其中viewmodel在Application.Reousrces中的DataTemplate处使用dataType定义。但是用户控件不绑定。有人可以帮助我吗？

    <Application.Resources>
        <DataTemplate DataType="{x:Type vm:MatterPanelViewModel}">
            <uc:MatterPanel />
        </DataTemplate>
    </Application.Resources>

将绑定用户控件的主窗口。

<Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:uc="clr-namespace:MyProject"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
        mc:Ignorable="d" x:Class="MyProject.MainWindow"
        Title="MyProject" WindowState="Maximized" d:DataContext="{d:DesignInstance Type=uc:MainWindowViewModel}">

    <Grid Grid.Row="2">
         <ContentControl Content="{Binding CurrentViewModel}" Margin="10,0,10,10" />
    </Grid>
</Window>

CurrentViewModel是MainViewModel的属性。

public class MainWindowViewModel:ViewModelBase
{
 private ViewModelBase _currentViewModel;
        public ViewModelBase CurrentViewModel
        {
            get { return this._currentViewModel; }
            set
            {
                if(this._currentViewModel == value) { return; }
                this._currentViewModel = value;
                this.NotifyOfPropertyChange(() => this.CurrentViewModel);
            }
        }

    public MatterPanelViewModel MatterPanelViewModel { get; set; }
public MainWindowViewModel()
        {
            this.MatterPanelViewModel = ServiceLocator.Current.GetService<MatterPanelViewModel>();
        }
}



 public class MatterPanelViewModel:ViewModelBase
        {
            public MatterPanelViewModel()
            {

            }
        }

ViewModelBase在这里，

public class ViewModelBase : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged
        {
            add { this._propertyChanged += value; }
            remove { this._propertyChanged -= value; }
        }

        private event PropertyChangedEventHandler _propertyChanged = delegate{ };

        protected void NotifyOfPropertyChange<T>(Expression<Func<T>> property)
        {
            var lambda = (LambdaExpression)property;
            MemberExpression memberExpression;
            if(lambda.Body is UnaryExpression)
            {
                var unaryExpression = (UnaryExpression)lambda.Body;
                memberExpression = (MemberExpression)unaryExpression.Operand;
            }
            else
            {
                memberExpression = (MemberExpression)lambda.Body;
            }
            this.NotifyOfPropertyChange(memberExpression.Member.Name);
        }
        public void NotifyOfPropertyChange(string property)
        {
            this.RaisePropertyChanged(property, true);
        }
        private void RaisePropertyChanged(string property, bool verifyProperty)
        {
            var handler = this._propertyChanged;
            if(handler != null)
            {
                handler(this, new PropertyChangedEventArgs(property));
            }
        }
    }

Answer 1

最后，我解决了这个问题。 viewmodel和usercontrol映射应在MainWindow下，但在主应用程序下。我只是从主应用编写代码

<Application.Resources>
        <DataTemplate DataType="{x:Type vm:MatterPanelViewModel}">
            <uc:MatterPanel />
        </DataTemplate>
    </Application.Resources>

到主窗口

<Window.Resources>
        <BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
        <DataTemplate DataType="{x:Type vm:MatterPanelViewModel}">
            <usc:MatterPanel/>
        </DataTemplate>
    </Window.Resources>

然后运行良好。

WPF：DataTemplate和UserControl映射不起作用

1 个答案: