在WPF中動態添加文本框

Question

我正在動態創建一個文本框。 我的網格中有2列。 如果其他文本框的值為“ tea”，我想向該行添加新的文本框。 我想創建新的文本框來更改對應的行文本框的值。 我無法使用標簽在此處獲取所選行。 因為我已經出於某些目的使用了Tag。 我對Tag不太了解。 無論如何，如何將新的文本框添加到對應行的column1？ 這是我的代碼。

    public int count = 1;
    public TextBox txt1;

    private void btn_addnew_Click(object sender, RoutedEventArgs e)
    {

        //Creating Rows..
        RowDefinition row0 = new RowDefinition();
        row0.Height = new GridLength(40);
        grid1.RowDefinitions.Add(row0);

        //Creating columns..
        ColumnDefinition col0 = new ColumnDefinition();
        ColumnDefinition col1 = new ColumnDefinition();

        col0.Width = new GridLength(150);
        col1.Width = new GridLength(250);

        grid1.ColumnDefinitions.Add(col0);
        grid1.ColumnDefinitions.Add(col1);

        int i = count;

        //1st Column TextBox

        txt1 = new TextBox();
        txt1.Margin = new Thickness(10, 10, 0, 0);
        Grid.SetRow(txt1, i);
        Grid.SetColumn(txt1, 0);

        txt1.Tag = txt1;

        txt1.MouseEnter+=txt1_MouseEnter;
        txt1.TextChanged += txt1_TextChanged;
        grid1.Children.Add(txt1);
        count++;
        }

    private void txt1_MouseEnter(object sender, MouseEventArgs e)
    {
        txt1 = ((TextBox)sender).Tag as TextBox;
        popup.IsOpen = true;
    }

    public TextBox txt2;
    private void txt1_TextChanged(object sender, TextChangedEventArgs e)
    {


        if (txt1.Text.ToString() == "Tea")
        {

            txt2 = new TextBox();

         //How to set row here?

            Grid.SetRow(txt2, ??);
            Grid.SetColumn(txt2, 1);

            txt2.Margin = new Thickness(10, 10, 0, 0);
            grid1.Children.Add(txt2);
        }
        else
        {              
            grid1.Children.Remove(txt2);
        }
    }

Answer 1

如果您只是想實現這一目標，那么更優雅的方法是將用戶控件添加到您的應用程序中，如下所示：

<UserControl x:Class="WpfApplication4.TestUserControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition/>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>
        <TextBox Name="TextBox1"/>
        <TextBox Grid.Column="1">
            <TextBox.Style>
                <Style TargetType="TextBox">
                    <Setter Property="Visibility" Value="Collapsed"/>
                    <Style.Triggers>
                        <DataTrigger Binding="{Binding Text, ElementName=TextBox1, UpdateSourceTrigger=PropertyChanged}" Value="tea">
                            <Setter Property="Visibility" Value="Visible"/>
                        </DataTrigger>
                    </Style.Triggers>
                </Style>
            </TextBox.Style>
        </TextBox>

    </Grid>
</UserControl>

然后在btn_addnew_Click（）方法中，只需將此用戶控件添加到用戶Grid並為其分配行和列即可。 文本框的顯示/隱藏將由用戶控件本身來處理。

    var userControl = new MyUserControl();
    userControl .Margin = new Thickness(10, 10, 0, 0);
    Grid.SetRow(userControl , i);

    grid1.Children.Add(userControl );

或者，如果您想為textbox1擁有Grid.Row的值，則可以直接通過以下方式獲取它：

        if (textbox1 != null)
        {
           int row = (int)textbox1.GetValue(Grid.RowProperty);
           Grid.SetRow(txt2, row);
        }

Answer 2

附加屬性可用於存儲此類信息，因此在類中定義附加屬性

    public static int GetGridRow(DependencyObject obj)
    {
        return (int)obj.GetValue(GridRowProperty);
    }

    public static void SetGridRow(DependencyObject obj, int value)
    {
        obj.SetValue(GridRowProperty, value);
    }

    // Using a DependencyProperty as the backing store for GridRow.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty GridRowProperty =
        DependencyProperty.RegisterAttached("GridRow", typeof(int), typeof(ViewModel), new PropertyMetadata(0));

然后用它來存儲行的值

private void btn_addnew_Click(object sender, RoutedEventArgs e)
{
    //1st Column TextBox

    txt1 = new TextBox();
    Grid.SetRow(txt1, i);
    SetGridRow(text1, i);
    ...
    grid1.Children.Add(txt1);
    count++;
}

然后在需要時使用它

//How to set row here?

Grid.SetRow(txt2, GetGridRow(txt1));
Grid.SetColumn(txt2, 1);