C#ref多态性解决方法

Question

我在C#中创建了一个函数:

private void customShow(Form someForm, Type formType) {
    if (someForm == null || someForm.IsDisposed) someForm = (Form)Activator.CreateInstance(formType);
    someForm.StartPosition = FormStartPosition.CenterScreen; 
    someForm.MdiParent = this;
    someForm.Show();
    someForm.WindowState = FormWindowState.Maximized;
}

然后我想这样做:

private void mnuKategori_Click(object sender, EventArgs e) {
    customShow(frmKategori, typeof(Master.FrmKategori));
    frmKategori.isCRUD = true;
}

它在方法的第二行失败,因为变量frmKategori在方法执行后仍为null.如果我将"someForm"参数引用到引用中,它也会失败,因为看起来C#不支持带有"ref"和"out"关键字的多态性.有没有人对此提出建议？在此先感谢您的回复.

Answer 1

也许泛型？

private void customShow<T>(ref T someForm) where T : Form, new()
{
    if (someForm == null || someForm.IsDisposed) someForm = new T();
    someForm.StartPosition = FormStartPosition.CenterScreen; 
    someForm.MdiParent = this;
    someForm.Show();
    someForm.WindowState = FormWindowState.Maximized;
}

然后我想这样做:

private void mnuKategori_Click(object sender, EventArgs e)
{
    customShow(ref frmKategori);
    frmKategori.isCRUD = true;
}