如何在后面的代碼中為同樣在后面的代碼中創建的文本塊在后面的代碼中創建數據綁定？

Question

我有以下代碼：

private void Ok_Click(object sender, MouseButtonEventArgs e)
{
    MainWindow win = (MainWindow)Application.Current.MainWindow;
    int i = 1;  // counter for the name of each new textblock
    string name = String.Concat("sample", i);

    // add textblok to the document list of new samples

    if (File_name.Text != "")
    {
        TextBlock sampleText = new TextBlock();


        sampleText.Text = File_name.Text;
        sampleText.FontSize = 14;
        sampleText.FontFamily = new FontFamily("Sans-serif");
        sampleText.FontWeight = FontWeights.DemiBold;
        sampleText.Margin = new Thickness(20,0,0,0);
        sampleText.Name = name;
        sampleText.PreviewMouseDown += new MouseButtonEventHandler(test1);
        sampleText.Visibility = System.Windows.Visibility.Collapsed;

        //binding 

        Binding myBinding = new Binding();
        myBinding.Source = Application.Current;
        myBinding.Path = new PropertyPath("sampleName");
        myBinding.Mode = BindingMode.TwoWay;
        myBinding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;
        sampleText.SetBinding(, myBinding);


        Grid.SetColumn(sampleText, 0);

        win.sp_s.Children.Add(sampleText);

        // checking if the drop down of sample is already open,
        //if so it will show the last textblock with pressing the arrow button.
        var TextBlock = win.sp_s.Children.OfType<TextBlock>().FirstOrDefault();
        if (TextBlock.Visibility == System.Windows.Visibility.Visible)
        {
            sampleText.Visibility = System.Windows.Visibility.Visible;
        }
    }
    i += 1;  // increasing the loop of names by 1
    this.Close();
}

我想將SetBinding方法的target屬性設置為TextBlock.TextProperty但是每當我編寫TextBlock ，都會出現錯誤提示

聲明之前不能使用局部變量'TextBlock'。

Answer 1

我懷疑問題出在此代碼-

var TextBlock = win.sp_s.Children.OfType<TextBlock>().FirstOrDefault();
        if (TextBlock.Visibility == System.Windows.Visibility.Visible)
        {
            sampleText.Visibility = System.Windows.Visibility.Visible;
        }

您已將變量名稱聲明為“ TextBlock”。 您試圖在綁定內設置的TextBlock.Text屬性與您在其下方聲明的變量名稱相混淆。 如果重命名此變量，則問題可能會得到解決。

 var textblock = win.sp_s.Children.OfType<TextBlock>().FirstOrDefault();
 if (textblock.Visibility == System.Windows.Visibility.Visible)
     {
         sampleText.Visibility = System.Windows.Visibility.Visible;
     }