WPF绑定不起作用； 视图未更新视图模型，反之亦然

Question

When I run the application and the vmMain object is initiated, the value of the textbox sampleCount and the string "Test" is printed out to the console, but it doesn't show in the view (in the textbox ). Also, Whenever I change the value of the textbox (from the view), nothing happen. As the property is not updated and nothing shows in the console.

MainwWindow.xaml:

    <Window x:Class="WpfApplication3.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApplication3" xmlns:oxy="http://oxyplot.org/wpf"
        xmlns:vm="clr-namespace:ViewModel;assembly=ViewModel"
        Background="#FFDEDEDE" 
        WindowStyle="None"
        AllowsTransparency="True"
       WindowStartupLocation="CenterScreen"

    mc:Ignorable="d"
        Title="Compression Test" Height="1080" Width="1920">


    <Window.Resources>
        <vm:MainViewModel x:Key="vmMain"
         sampleCount="100" />
    </Window.Resources>
    <Grid x:Name="gridUI">

        <StackPanel Orientation="Vertical">
            <StackPanel Height="100">

                <Border Background="#FF8986D3" Height="100" Margin="0,0,0,30" >

                    <TextBlock Text="COMPRESSION TEST"  FontFamily="Sans-serif" FontSize="30" Foreground="#FFF9F9F9" VerticalAlignment="Center" FontWeight="Medium" HorizontalAlignment="Center"/>

                </Border>

            </StackPanel>

            <StackPanel Orientation="Horizontal" Height="auto">
                <Border BorderBrush="White" BorderThickness="2" >
                <StackPanel Orientation="Vertical" Width="200" Height="1080">


                    <Label  FontSize="24" FontFamily="Sans-serif" FontWeight="Medium" Name="doc" Foreground="White" Background="#FFA39AD8" Width="200" HorizontalContentAlignment="Center" Height="43">Files</Label>
                    <Border BorderBrush="#FFD4D4D4" BorderThickness="0.5" Grid.Row="3"></Border>


                    <StackPanel Name="sp_doc" Margin="0,10,0,0" >
                        <StackPanel Orientation="Horizontal"  Name="sp_sample_button" Grid.Row="0" Grid.Column="0">
                            <Image Source="pack://application:,,,/Resources/413.png" Height="40" Width="40"  UseLayoutRounding="True"   MouseDown="sampleDropDown" Cursor="Hand" Margin="5,0,0,0" Name="up_arrow"/>
                            <Image Source="pack://application:,,,/Resources/412.png" Height="40" Width="40"  UseLayoutRounding="True"   MouseDown="sampleDropDown" Cursor="Hand" Margin="5,0,0,0" Name="down_arrow" Visibility="Collapsed"/>
                            <!--<Button x:Name="sss" Click="sampleDropDown">s</Button>-->
                            <Label FontSize="18" FontFamily="Sans-serif" FontWeight="Light" Name="sam" Foreground="White" Margin="10">Samples</Label>

                        </StackPanel>
                        <StackPanel Orientation="Vertical" Name="sp_s">

                        </StackPanel>
                        <StackPanel Orientation="Horizontal" Grid.Column="1" Grid.Row="1">
                            <Image Source="pack://application:,,,/Resources/413.png" Height="40" Width="40"  UseLayoutRounding="True"  RenderTransformOrigin="-0.,0.558" MouseDown="reportDropDown" Cursor="Hand" Margin="5,0,0,0" Name="up_arrow1"/>
                            <Image Source="pack://application:,,,/Resources/412.png" Height="40" Width="40"  UseLayoutRounding="True"  Cursor="Hand" Margin="5,0,0,0" Name="down_arrow1" Visibility="Collapsed" MouseDown="reportDropDown"/>
                            <!--<Button Click="reportDropDown">r</Button>-->
                            <Label FontFamily="Sans-serif" FontWeight="Light" Foreground="White" FontSize="18" Margin="10">Reports</Label>
                        </StackPanel>
                        <StackPanel Orientation="Vertical" Name="sp_r">

                        </StackPanel>

                    </StackPanel>




                </StackPanel>
                </Border>
                <StackPanel Width="1781">
                    <StackPanel Orientation="Horizontal" Background="#FFFDFDFD" Height="111">
                        <TextBox Name="sampleCount" DataContext="{Binding sampleCount, Source={StaticResource vmMain}}" Width="200"></TextBox>
                        <Button Cursor="Hand"  Height="75" Width="75" Style="{StaticResource CircleButton}"  FontFamily="Sans-Serif" FontSize="25" Foreground="White" Click="NewSample_Click" Content="+" Margin="20,0,0,0" Background="#FFACAABF" />

                        <StackPanel Margin="20,19,0,0">
                            <Image Source="pack://application:,,,/Resources/file512.png" Height="75" Width="75"  UseLayoutRounding="True" Margin="0,0,0,0"  MouseDown="CreateReport_Click" Cursor="Hand" SnapsToDevicePixels="True"/>
                        </StackPanel>

                        <Image Source="pack://application:,,,/Resources/play1.png" Height="75" Width="75"  UseLayoutRounding="True" Margin="20,18,0,18"  MouseDown="CreateReport_Click" Cursor="Hand" SnapsToDevicePixels="True"/>

                        <Image Source="pack://application:,,,/Resources/1131.png" Height="75" Width="75"  UseLayoutRounding="True" Margin="1340,0,0,0"  MouseDown="CreateReport_Click" Cursor="Hand"/>

                    </StackPanel>
                    <Frame x:Name="newSampleFrame" Content="" HorizontalAlignment="center" VerticalAlignment="center" Width="934" Height="456" NavigationUIVisibility="Hidden" RenderTransformOrigin="0.408,0.5" Visibility="Collapsed"/>
                    <Frame x:Name="reportFrame"  Content=""  HorizontalAlignment="Center" Height="842" VerticalAlignment="Center" Width="595" Margin="0,100,0,0" NavigationUIVisibility="Hidden"/>
                    <Frame x:Name="graphFrame"  Content="" HorizontalAlignment="Center" Height="456"  VerticalAlignment="Center" Width="934" NavigationUIVisibility="Hidden" Visibility="Collapsed"/>
                </StackPanel>


            </StackPanel>
        </StackPanel>

    </Grid>
</Window>

MainViewModel.cs :

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;

    namespace ViewModel
     {
     public class MainViewModel : ObservableObject
      {
     public MainViewModel()
     {

     }
    private int[]  sampleName;
    private string _sampleCount;



    public int this[int pos]
    {
        get
        {
            return sampleName[pos];
        }

        set
        {
            sampleName[pos] = value;
        }

    }

   public string sampleCount
    {
        get
        {
            return _sampleCount;

        }
        set
        {
            if (value != _sampleCount)
            {
                _sampleCount = value;
                OnPropertyChanged("sampleCount");
                Console.WriteLine("Test");
                Console.WriteLine(value);
            }
        }
     }

  } 
}

ObservableObject.cs :

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ViewModel
{
public abstract class ObservableObject : INotifyPropertyChanged
{
    #region INotifyPropertyChanged Members


    public event PropertyChangedEventHandler PropertyChanged;


    protected virtual void OnPropertyChanged(string propertyName)
    {
        this.VerifyPropertyName(propertyName);

        if (this.PropertyChanged != null)
        {
            var e = new PropertyChangedEventArgs(propertyName);
            this.PropertyChanged(this, e);
        }
    }

    #endregion // INotifyPropertyChanged Members

    #region Debugging Aides


    [Conditional("DEBUG")]
    [DebuggerStepThrough]
    public virtual void VerifyPropertyName(string propertyName)
    {

        if (TypeDescriptor.GetProperties(this)[propertyName] == null)
        {
            string msg = "Invalid property name: " + propertyName;

            if (this.ThrowOnInvalidPropertyName)
                throw new Exception(msg);
            else
                Debug.Fail(msg);
        }
    }


    protected virtual bool ThrowOnInvalidPropertyName { get; private set; }

    #endregion // Debugging Aides
}

}

Answer 1

您需要绑定Text属性：

Text={Binding sampleCount}