使用LINQ，如何获得所有标签控件 [英] Using LINQ, how do you get all label controls

问题描述

我想获取属于用户控件的所有标签控件的集合.我有以下代码:

I want to get a collection of all label controls that are part of a user control. I have the following code:

        var labelControls = from Control ctl in this.Controls
                            where ctl.GetType() == typeof(Label)
                            select ctl;

，但结果为零结果.

请协助.谢谢.

编辑 我还尝试了以下代码，但未成功.

Edit I have also tried the following code without success.

        this.Controls
            .OfType<Label>()
            .Where(ctl => ctl.ID.Contains("myPrefix"))
            .ToList()
            .ForEach(lbl => lbl.ForeColor = System.Drawing.Color.Black);

再次，没有成功.

推荐答案

您确定要解析其子控件的控件实际上直接包含Label控件吗?我怀疑托管标签的是主控件的子级，在这种情况下，您需要递归搜索UI树以找到标签.

Are you sure that the control whose child controls you are parsing actually directly contains Label controls? I suspect that it is a child of the main control that is hosting the labels, in which case, you need to recursively search through the UI tree to find the labels.

类似的东西:

public static IEnumerable<Label> DescendantLabels(this Control control)
{
   return control.Controls.DescendantLabels();
}

public static IEnumerable<Label> DescendantLabels(this ControlCollection controls)
{
    var childControls = controls.OfType<Label>();

    foreach (Control control in controls)
    {
       childControls = childControls.Concat(control.DescendantLabels());
    }

    return childControls;
}

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