在运行时确定控件是否允许在设计时向其添加其他控件 [英] Determine at run time if a control allows other controls to be added to it at design time

问题描述

我需要操纵表单上的所有控件。我可以访问Controls集合来做到这一点。问题在于试图包含容器控件中包含的所有控件，例如 GroupBox 或 Panel 。我可以递归地迭代每个Control自己的Controls集合，但这随后将访问所有非设计时间容器的构成控件。

I need to manipulate all controls on a form. I'm fine with accessing the Controls collection to do this. The problem comes with trying to include any controls contained within container controls such of GroupBox or Panel. I could recursively iterate the each Control's own Controls collection but this then accesses all constituent controls for non-design time containers.

由于我的非容器控件均管理其构成控件'根据自己的属性声明状态，我不会开始弄乱组成控件。

Since my non-container controls all manage their constituent controls' state based on the their own properties I don't to start messing with constituent controls.

如何确定控件是否是设计时间容器，以便我可以避免处理那些不是？

How can I determine if a control is a design time container so that I can avoid process those that are not?

我尝试检查Designer属性，但这对于 ComboBox 和 GroupBox ：

I've tried checking for the Designer attribute but this returns null for both the ComboBox and the GroupBox:

foreach(Attribute attr in typeof(ctl).GetCustomAttributes(typeof(Attribute), false))
{
    if(typeof(DesignerAttribute).IsAssignableFrom(attr.GetType()))
{
    DesignerAttribute da = (DesignerAttribute)attr;
    }
}

ctl 的类型为 Control ，在我的测试中为 Combox 或 GroupBox 。

ctl is of type Control and in my testing is either Combox or GroupBox.

在两种情况下， GetCustomAttributes 返回的数组都是1个属性，即工具箱图标

In both cases the GetCustomAttributes returns an array of 1 attribute which is the toolbox icon.

我也尝试检查从 ContainerControl 类的可分配性，但是它们都是因为，我认为，它们都将在运行时包含控件。

I've also tried checking assignability from to the ContainerControl class but they both are because, I assume, they will both contain controls at run time.

如何检测设计时间容器？

How do I detect a design time container?

推荐答案

在如果Hans不回来，并且有人感兴趣，这是我根据Hans Passant的建议解决问题的方法：

In case Hans doesn't come back, and anyone is interested, this is my solution to the problem based on Hans Passant's suggestion:

    public static bool IsContainerControl(this Control ctl)
    {
        if (ctl == null)
            return false;

        MethodInfo GetStyle = ctl.GetType().GetMethod("GetStyle", BindingFlags.NonPublic | BindingFlags.Instance);
        if (GetStyle == null)
            return false;

        return (bool)GetStyle.Invoke(ctl, new object[] { ControlStyles.ContainerControl });
    }

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