Question

好奇的情况：

public class MyTextBox : TextBox
{
    // I want use the same height for all MyTextBoxes
    public new static int Height;
}

public Form1()
{
    InitializeComponent();

    MyTextBox mtb1 = new MyTextBox();
    MyTextBox mtb2 = new MyTextBox();

    mtb1.Multiline = true;
    mtb2.Multiline = true;

    mtb1.Location = new Point(50, 100);
    mtb2.Location = new Point(200, 100);

    mtb1.Size = new Size(50, 50);
    mtb2.Size = new Size(150, 150);

    Controls.Add(mtb1);
    Controls.Add(mtb2);

    mtb1.Text = mtb1.Height;
    mtb2.Text = mtb2.Height;
    // Error 1 Member 'WindowsFormsApplication9.MyTextBox.Height'
    // cannot be accessed with an instance reference;
    // qualify it with a type name instead
}

VB.NET中的相同内容

Public Class MyTextBox
    Inherits TextBox
    Public Shared Shadows Height As Integer
End Class

mtb1.Text = mtb1.Height ' Text will be "0" '
'Warning 1   Access of shared member, constant member, enum member or nested '
' type through an instance; qualifying expression will not be evaluated.

问题：

==

无法使用此方法习惯隐藏继承的公共成员班？有时这可以有用...
如何为所有成员使用相同的Height？

Answer 1

什么时候有用？我真的不认为用这种方式隐藏成员是个好主意。这只会导致维护噩梦 - 当你看到“高度”时，你不能轻易分辨出它真正指的是哪个成员。

IMO，“new”应该只用作最后的绝望行为，通常是在基类引入了与您现有的一个成员冲突的成员时。它不应该被用作故意避免正常OO设计原则的方式。

新的静态字段和隐藏公共继承的成员

1 个答案: