在Silverlight中查找所有TextBox控件的通用方法

Question

我在页面上有几个Silverlight控件,并希望查询所有类型为TextBox的控件并使其正常工作.

现在我正在处理的Silverlight表单可以添加更多的TextBox控件.所以当我测试一下TextBox控件是否有值时,我可以这样做:

if (this.TextBox.Control.value.Text() != String.Empty)
{
    // do whatever
}

但我宁愿有灵活性,我可以在任何Silverlight表单上使用它,无论我有多少TextBox控件.

关于如何做到这一点的任何想法？

Answer 1

我已经遇到过这个问题,请在此处通知:http://megasnippets.com/en/source-codes/silverlight/Get_all_child_controls_recursively_in_Silverlight

这里有一个通用的方法可以在VisualTree中以递归方式查找所有TextBox:

IEnumerable<DependencyObject> GetChildrenRecursively(DependencyObject root)
{
    List<DependencyObject> children = new List<DependencyObject>();
    children.Add(root);
    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(root); i++)
        children.AddRange(GetChildrenRecursively(VisualTreeHelper.GetChild(root, i)));

    return children;
}

像这样使用此方法来查找所有TextBox:

var textBoxes = GetChildrenRecursively(LayoutRoot).OfType<TextBox>();

Answer 2

听起来你需要像下面的GetTextBoxes 这样的递归例程:

void Page_Loaded(object sender, RoutedEventArgs e)
{
    // Instantiate a list of TextBoxes
    List<TextBox> textBoxList = new List<TextBox>();

    // Call GetTextBoxes function, passing in the root element,
    // and the empty list of textboxes (LayoutRoot in this example)
    GetTextBoxes(this.LayoutRoot, textBoxList);

    // Now textBoxList contains a list of all the text boxes on your page.
    // Find all the non empty textboxes, and put them into a list.
    var nonEmptyTextBoxList = textBoxList.Where(txt => txt.Text != string.Empty).ToList();

    // Do something with each non empty textbox.
    nonEmptyTextBoxList.ForEach(txt => Debug.WriteLine(txt.Text));
}

private void GetTextBoxes(UIElement uiElement, List<TextBox> textBoxList)
{
    TextBox textBox = uiElement as TextBox;
    if (textBox != null)
    {
        // If the UIElement is a Textbox, add it to the list.
        textBoxList.Add(textBox);
    }
    else
    {
        Panel panel = uiElement as Panel;
        if (panel != null)
        {
            // If the UIElement is a panel, then loop through it's children
            foreach (UIElement child in panel.Children)
            {
                GetTextBoxes(child, textBoxList);
            }
        }
    }
}

实例化一个空文本框列表.调用GetTextBoxes,传入页面上的根控件(在我的例子中,就是this.LayoutRoot),GetTextBoxes应递归循环遍历该控件后代的每个UI元素,测试它是否是TextBox(添加它)列表)或小组,可能有它自己的后代来递归.

希望有所帮助.:)