Question

我已经使用一些其他选项实现了自定义按钮控件。并将我的自定义按钮添加到表单中。当我设置Form.Acception是添加的自定义按钮，然后我想在Button中进行一些自定义。我想在自定义按钮类实现中自定义按钮外观，当它标记为Form的AcceptButton时。

任何人都建议我怎么知道按钮被标记为Button类中表单的AcceptButton？

Answer 1

<强> WRONG：

protected override void OnLoad（EventArgs e） { base.OnLoad（E）; if（（（Form）this.TopLevelControl）.AcceptButton == this） .... }

<强> UPD：

public class MyButton : Button
    {
        public override void NotifyDefault(bool value)
        {
            if (this.IsDefault != value)
            {
                this.IsDefault = value;
            }

            if (IsDefault)
            {
                this.BackColor = Color.Red;
            }
            else
            {
                this.BackColor = Color.Green;
            }
        }
    }

Answer 2

您可以遍历父级以通过其基类Control的父属性查找表单：

public partial class MyButton : Button
{
    public MyButton()
    {
        InitializeComponent();
    }

    private Form CheckParentForm(Control current)
    {
        // if the current is a form, return it.
        if (current is Form)
            return (Form)current;

        // if the parent of the current not is null, 
        if (current.Parent != null)
            // check his parent.
            return CheckParentForm(current.Parent);

        // there is no parent found and we didn't find a Form.
        return null;
    }

    protected override void OnCreateControl()
    {
        base.OnCreateControl();

        // find the parent form.
        var form = CheckParentForm(this);

        // if a form was found, 
        if (form != null)
            // check if this is set as accept button
            if (this == form.AcceptButton)
                // for example, change the background color (i used for testing)
                this.BackColor = Color.RosyBrown;
    }
}

由于递归，当Button放在Panel上时它也可以工作。

注意：必须在调用OnCreateControl 之前设置接受按钮（例如，在表单的构造函数中）

经过一些googling我发现了一个标准实现：

您还可以使用：this.FindForm();

public partial class MyButton : Button
{
    public MyButton()
    {
        InitializeComponent();

    }

    protected override void OnCreateControl()
    {
        base.OnCreateControl();

        var form = FindForm();

        if (form != null)
            if (this == form.AcceptButton)
                this.BackColor = Color.RosyBrown;

    }
}

C＃6.0中的事件更短：

public partial class MyButton : Button
{
    public MyButton()
    {
        InitializeComponent();

    }

    protected override void OnCreateControl()
    {
        base.OnCreateControl();

        if (this == FindForm()?.AcceptButton)
            this.BackColor = Color.RosyBrown;
    }
}

<强> \ O /

如果设置表单的AcceptButton，我如何自定义按钮？

2 个答案: