Question

我为此进行了大量搜索，但似乎无法弄清楚。（只是说，这将是一长篇文章）

前言：这不是MVVM

问题：我有一个进度条。我目前正在尝试从xaml的.cs文件中将公共双精度文件绑定到它。但是，每当我使用值的绑定函数时，它就永远无法工作，导致iNotifyPropertyChanged无法正常工作，等等。

它绑定到的变量用于更新进度条值。完成方法是通过在另一个方法/类的单独的for循环中设置值。该值由一个简单的方程式设置。 100除以列表长度，再乘以for循环计数器。这为我们提供了可以输入进度条值的实数。（下面的代码）

    Binder.daWindow.progUpdate = ((100.00 / databaseTables.Length) * dbTIndex);

我知道这可以通过线程（或其他任何方式）完成，但是我特别希望得到有关如何通过绑定来完成此操作的答案（除非这是不可能的，然后忘记我刚才说的话）。

XAML：

<Window x:Name="DateWindow1" x:Class="WpfApp1.DateWindow"
    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:WpfApp1"
    xmlns:Main="using:DateWindow"
    mc:Ignorable="d"
    Title="Change Dates" Height="232.667" Width="462" Background="#FF2B2B2B" ResizeMode="NoResize">



    <Grid>
    <TextBox x:Name="DayChangeTextBox" HorizontalAlignment="Left" Height="30" Margin="176,45,0,0" TextWrapping="Wrap" Text="##" VerticalAlignment="Top" Width="58" FontSize="14" TextAlignment="Center" AcceptsReturn="False" AcceptsTab="False" GotFocus="DayChangeTextBox_GotFocus" LostFocus="DayChangeTextBox_LostFocus" BorderThickness="1" BorderBrush="Black" OpacityMask="Black" Background="#FFFDFDFD"/>
    <Label Content="Days" HorizontalAlignment="Left" Margin="239,45,0,0" VerticalAlignment="Top" Width="42" FontSize="14" FontFamily="Microsoft YaHei UI" Height="30" Foreground="White"/>
    <Label Content="Move Dates Forward:" HorizontalAlignment="Left" Margin="23,45,0,0" VerticalAlignment="Top" Width="144" FontSize="14" FontFamily="Microsoft JhengHei UI Light" Height="30" Foreground="White"/>
    <Button x:Name="ChangeDatesButton" Content="Change Dates" HorizontalAlignment="Left" Margin="303,45,0,0" VerticalAlignment="Top" Width="143" Height="30" BorderThickness="1,1,2,3" BorderBrush="#FF474747" Click="ChangeDatesButton_Click" FontFamily="Microsoft YaHei UI" Background="#FFE6E6E6"/>
    <Label x:Name="serverLabel" Content="Label" HorizontalAlignment="Left" Margin="10,73,0,0" VerticalAlignment="Top" RenderTransformOrigin="0.5,0.5" Width="5" Height="15" Visibility="Hidden"/>
    <Label x:Name="databaseLabel" Content="Label" HorizontalAlignment="Left" Margin="20,73,0,0" VerticalAlignment="Top" Width="3" Visibility="Hidden" Height="15"/>
    <Button x:Name="RevertToDefaultButton" Content="Revert to Backup" Margin="23,164,0,0" VerticalAlignment="Top" Height="30" Background="#FFE6E6E6" BorderBrush="#FF474747" BorderThickness="1,1,2,3" Click="RevertToDefaultButton_Click" FontFamily="Microsoft JhengHei UI" HorizontalAlignment="Left" Width="143"/>
    <Button x:Name="OverwriteDefaultButton" Content="Backup Database" Margin="23,128,0,0" VerticalAlignment="Top" Height="30" BorderBrush="#FF474747" BorderThickness="1,1,2,3" Click="OverwriteDefaultButton_Click" FontFamily="Microsoft JhengHei UI" HorizontalAlignment="Left" Width="143" Background="#FFE6E6E6" />
    <Button x:Name="CloseButton" Content="Close" Margin="0,164,10,0" VerticalAlignment="Top" Height="30" BorderBrush="#FF474747" BorderThickness="1,1,2,3" FontFamily="Microsoft JhengHei UI" Width="60" Click="CloseButton_Click" HorizontalAlignment="Right" Background="#FFE6E6E6" />
    <Label x:Name="RevertBackupLabel" Content="Backup or Revert Database:" HorizontalAlignment="Left" Margin="12,93,0,0" VerticalAlignment="Top" Foreground="White" FontFamily="Microsoft JhengHei UI" FontWeight="Bold" FontSize="16"/>
    <Label x:Name="DatesLabel" Content="Change Dates in Database:" Margin="12,10,0,0" Foreground="White" FontFamily="Microsoft JhengHei UI" FontWeight="Bold" FontSize="16" HorizontalAlignment="Left" Width="216" Height="30" VerticalAlignment="Top"/>
    <ProgressBar HorizontalAlignment="Left" Height="13" Margin="303,80,0,0" VerticalAlignment="Top" Width="143" Name="pbStatus"  Value="{Binding local.progUpdate, UpdateSourceTrigger=PropertyChanged}" Maximum="{Binding mx}" Minimum="{Binding mn}" LargeChange="0.01"/>
</Grid>

XAML CS部分：

public static class Binder
{
    public static DateWindow daWindow;
}
public partial class DateWindow : Window, INotifyPropertyChanged
{

    private double _progUpdate;
    public double progUpdate
    {
        get { return _progUpdate; }
        set
        {
            _progUpdate = value;
            if (PropertyChanged != null)
            {
                PropertyChanged.Invoke(this, new PropertyChangedEventArgs(nameof(progUpdate)));
            }

        }

    }
    public double mx = 100;
    public double mn = 0; 


    public event PropertyChangedEventHandler PropertyChanged;
    public DateWindow()
    {
        InitializeComponent();
        Binder.daWindow = this; 
        ChangeDateInDatabase ChangeDate = new ChangeDateInDatabase();
        progUpdate = 25; // This is there so we can test the variable without going through the whole program. 
    }

    private void ChangeDatesButton_Click(object sender, RoutedEventArgs e)
    {
        ChangeDateInDatabase ChangeDate = new ChangeDateInDatabase();
        var result = MessageBox.Show("Are you sure you would like to change dates for  " + Globals.selectedDatabase + " from server " + Globals.main.ServerComboBox.Text + "?", "Change Dates?", MessageBoxButton.YesNo, MessageBoxImage.Exclamation);
        if (Globals.main.ServerComboBox.Text != "" && Globals.selectedDatabase != "" && FindDatabaseAndServer.Connector(Globals.main.ServerComboBox.Text, Globals.selectedDatabase) && result == MessageBoxResult.Yes)
        {
            try
            {
                long.Parse(DayChangeTextBox.Text);
                ChangeDate.ChangeDates(this); 
                //ChangeDateInDatabase.ChangeDates(this);

            }
            catch
            {
                MessageBox.Show($"Invalid number {DayChangeTextBox.Text}, please enter a valid number.", "ERROR", MessageBoxButton.OK, MessageBoxImage.Error);
            }
        }
    }

（CLICK函数用于为程序调用方法。在方法内部，其主循环（确定方法完成）包含希望与值定义方程式绑定的变量）

包含所述循环的方法：

for (int dbTIndex = 0; dbTIndex < databaseTables.Length; dbTIndex++)
                    {
                        string[] dateColumns = new string[0];
                        string columnSelectQuery = "SELECT DATA_TYPE, COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS  WHERE TABLE_NAME = '" + databaseTables[dbTIndex].ToString() + "' AND COLUMN_NAME LIKE '_%'";
                        using (SqlConnection connection2 = new SqlConnection(connectionString))
                        {
                            SqlCommand command2 = new SqlCommand(columnSelectQuery, connection2);
                            connection2.Open();
                            SqlDataReader reader2 = command2.ExecuteReader();
                                int y = 0;
                                while (reader2.Read())
                                {
                                    if (reader2[0].ToString() == "datetime")
                                    {
                                        Array.Resize(ref dateColumns, dateColumns.Length + 1);
                                        dateColumns[y] = reader2[1].ToString();
                                        y++;
                                    }
                                }
                        }
                        for (var dtColIndex = 0; dtColIndex < dateColumns.Length; dtColIndex++)
                        {
                            string addDatesQuery = "UPDATE " + databaseTables[dbTIndex] + " SET " + dateColumns[dtColIndex] + " = DATEADD(dd," + Convert.ToInt32(date.DayChangeTextBox.Text) + "," + dateColumns[dtColIndex] + ") WHERE " + dateColumns[dtColIndex] + " IS NOT NULL";

                            using (SqlConnection connection3 = new SqlConnection(connectionString))
                            {
                                    SqlCommand command3 = new SqlCommand(addDatesQuery, connection3);
                                    connection3.Open();
                                    command3.ExecuteNonQuery();
                            }
                        }
                        //vvvvv VARIABLE THAT NEEDS TO BE BOUND vvvvvvv
                        Binder.daWindow.progUpdate = ((100.00 / databaseTables.Length) * dbTIndex);
                    }

（这部分显然还有更多代码，我可以根据需要提供）

谢谢！

编辑：

对于XAML，local.progUpdate不是我尝试过的唯一方法。我已经完成了路径，自行完成了progUpdate等。

Answer 1

您的ProgressBar的第一个绑定没有意义：{Binding local.progUpdate, UpdateSourceTrigger=PropertyChanged}。您没有指定源，也没有在任何地方分配DataContext，因此绑定不会对任何内容求值，因为该路径是没有意义的。由于该属性位于窗口本身上，因此您只需将窗口的数据上下文分配给它本身即可。

// DateWindow.xaml.cs
public DateWindow()
{
    InitializeComponent();
    DataContext = this;
    ...
}

<!-- DateWindow.xaml -->
<ProgressBar Value="{Binding progUpdate, Mode=OneWay}" ... />

您的其他绑定将要求mx和mn是属性而不是字段。

数据绑定进度栏未绑定

1 个答案: