c#显示子窗体的问题
c#中显示MDI子窗体的方法是把mainform的ismdicontainer=true;再在要显示子窗体的地方加入childform child=new 
childform;child.mdiparent=this;child.show();可是我在mainform中放了个menuStrip，在menuStrip的一个菜单项的单击事件中childform child=new childform（）;child.mdiparent=this;child.show();（mainform的ismdicontainer已经设为true)但是怎么都显示不出来？
继承的都是窗体类（From），而且能运行。就是菜单项按钮点击没反映


------解决方案--------------------
应该没啥问题的，给你个简单例子

Form1.cs

public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void newToolStripMenuItem_Click(object sender, EventArgs e)
{
Form childForm = new Form();
childForm.MdiParent = this;
childForm.Show();
}
}

Form1.Desiger.cs

partial class Form1
{
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;

/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}

#region Windows Form Designer generated code

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.menuStrip1 = new System.Windows.Forms.MenuStrip();
this.fileToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
this.newToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
this.menuStrip1.SuspendLayout();
this.SuspendLayout();
// 
// menuStrip1
// 
this.menuStrip1.Items.AddRange(new System.Windows.Forms.ToolStripItem[] {
this.fileToolStripMenuItem});
this.menuStrip1.Location = new System.Drawing.Point(0, 0);
this.menuStrip1.Name = "menuStrip1";
this.menuStrip1.Size = new System.Drawing.Size(292, 24);
this.menuStrip1.TabIndex = 1;
this.menuStrip1.Text = "menuStrip1";
// 
// fileToolStripMenuItem
// 
this.fileToolStripMenuItem.DropDownItems.AddRange(new System.Windows.Forms.ToolStripItem[] {
this.newToolStripMenuItem});
this.fileToolStripMenuItem.Name = "fileToolStripMenuItem";
this.fileToolStripMenuItem.Size = new System.Drawing.Size(41, 20);
this.fileToolStripMenuItem.Text = "File";
// 
// newToolStripMenuItem
// 
this.newToolStripMenuItem.Name = "newToolStripMenuItem";
this.newToolStripMenuItem.Size = new System.Drawing.Size(152, 22);
this.newToolStripMenuItem.Text = "New";
this.newToolStripMenuItem.Click += new System.EventHandler(this.newToolStripMenuItem_Click);
// 
// Form1
// 
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;