Question

我有以下代码：

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();
}

我想将SetBinding方法的目标属性设置为TextBlock.TextProperty，但每当我写TextBlock时，我都会收到错误消息

在声明之前不能使用局部变量'TextBlock'。

Answer 1

我怀疑这个代码存在问题 -

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

您已将变量名称声明为“TextBlock”。您尝试在绑定中设置的TextBlock.Text属性与您在其下面声明的此变量名称相混淆。如果重命名此变量，问题可能会得到解决。

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

如何在后面的代码中创建的文本块中创建数据绑定？

1 个答案: