在winform下實現左右布局多窗口界面的方法

2020-01-24 01:15:25

字體：大中小

來源：轉載

供稿：網友

在web頁面上我們可以通過frameset,iframe嵌套框架很容易實現各種導航+內容的布局界面，而在winform、WPF中實現其實也很容易，我這里就分享一個：在winform下實現左右布局多窗口界面。

我這里說的多窗口是指一個父窗口包含多個子窗口，在winform中實現這種效果很簡單，即將某個窗口的IsMdiContainer設為true,然后將其它子窗口的MdiParent設為其父窗口對象即可，這樣就完成了一個多窗口界面，效果如下：

點擊NEW新打開一個窗口，其效果如下：

請看我上圖紅色標注的地方，Windows菜單項下面顯示的是當前所有已打開的子窗口，點擊某個菜單，即可快速切換到其它窗口，若關閉某個子窗口，與之相對應的菜單項也會自動被移除，實現這個功能也很簡單，只需要將菜單的MdiWindowListItem屬性設為需要顯示活動窗口列表的菜單項即可，如：this.menuStrip1.MdiWindowListItem = this.windowsToolStripMenuItem;

上述示例完整的實現代碼如下：

public partial class FormMdi : Form{private int formCount = 0;public FormMdi(){InitializeComponent();this.menuStrip1.MdiWindowListItem = this.windowsToolStripMenuItem;}private void newToolStripMenuItem_Click(object sender, EventArgs e){ShowChildForm<FormChild>();}private void ShowChildForm<TForm>() where TForm : Form, new(){TForm childForm = new TForm();childForm.Name = "frm" + Guid.NewGuid().ToString("N");childForm.Text = string.Format("Child Form -{0}", ++formCount);childForm.MdiParent = this;childForm.WindowState = FormWindowState.Maximized;childForm.Show();}}

相信實現上面這部份功能一般用過winform的人都會操作，我這里就當是復習順便給新手一個參考，同時也為下面要實現的左右布局功能做一個鋪墊吧。

要實現左右布局，并且能夠支持可動態調整左右占比的功能，非SplitContainer控件莫屬了，如果不了解該控件用法請自行在網上查找相關資料，我這里就不作說明，如果要顯示WINDOWS已打開的子窗口情況，同樣也需要用到MenuStrip控件，

最終設計的主窗口（FormMain）效果如下：

我這里因為只是演示，所以菜單控件上我只添加了兩個菜單項，分別為：WINDOWS，用于顯示WINDOWS已打開的子窗口列表，NEW，用于打開一個子窗口；SplitContainer控件全部采用默認的，沒有放置任何控件在其中，如果用在正式系統中，一般左邊Panel1中會放置一個樹形菜單，右邊Panel2中保持空即可，因為這個是用來作為子窗口的容器。

控件層次結構如下圖示：

界面設計好了，下面就實現最重要的兩個功能。

第一個功能：在右邊Panel2中顯示子窗口，實現代碼如下：

public FormMain()｛this.IsMdiContainer = true;｝private void ShowChildForm<TForm>() where TForm : Form, new(){TForm childForm = new TForm();childForm.Name = "frm" + Guid.NewGuid().ToString("N");childForm.Text = string.Format("Child Form -{0}", ++formCount);childForm.MdiParent = this;childForm.Parent = splitContainer1.Panel2;childForm.WindowState = FormWindowState.Maximized;childForm.Show();}

簡要說明:

1.在窗口構造函數中動態的將IsMdiContainer設為true,當然也可以設計視圖中設置；

2.編寫一個顯示寫子窗口的方法，方法中需注意的地方：childForm.MdiParent = this；childForm.Parent = splitContainer1.Panel2，意思是：將當前窗口作為子窗口的父窗口，同時將Panel2指定為子窗口的父對象，這樣就能實現子窗口在Panel2中打開了。

第二個功能：在WINDOWS菜單項下顯示已打開的子窗口列表，這里實現就沒有像文章一開始介紹的那樣簡單，使用那個方法是無效的，需要我們來自行實現，稍微有點復雜，但如果明白其實現原理，也就簡單明白了。

實現思路：當childForm加載到Panel2時，會觸發Panel2.ControlAdded事件，當childForm被關閉時，會觸發Panel2.ControlRemoved事件，我們可以統一訂閱這兩個事件，當childForm加載時，那么就在WINDOWS菜單項下增加一個菜單項，反之則移除該菜單項，實現代碼如下：

this.splitContainer1.Panel2.ControlAdded += Panel2_ControlChanged;this.splitContainer1.Panel2.ControlRemoved += Panel2_ControlChanged;void Panel2_ControlChanged(object sender, ControlEventArgs e){var frm = e.Control as Form;string menuName = "menu_" + frm.Name;bool exists = this.splitContainer1.Panel2.Controls.Contains(frm);if (exists){var menuItem = GetMenuItem(menuName);if (menuItem != null){menuItem.Checked = true;frm.BringToFront();frm.Focus();}else{windowsToolStripMenuItem.DropDownItems.Add(new ToolStripMenuItem() { Text = frm.Text, Name = menuName, Tag = frm, Checked = true });}}else{var menuItem = GetMenuItem(menuName);if (menuItem != null){windowsToolStripMenuItem.DropDownItems.Remove(menuItem);menuItem.Dispose();}}}private ToolStripMenuItem GetMenuItem(string menuName){var menuItems = windowsToolStripMenuItem.DropDownItems.Cast<ToolStripMenuItem>();menuItems.ToList().ForEach(m => m.Checked = false);return menuItems.Where(m => m.Name == menuName).SingleOrDefault();}

同時為了實現點擊WINDOWS菜單項的子菜單能夠快速切換子窗口，需要訂閱WINDOWS菜單項的DropDownItemClicked事件，當然也可以為新增的子菜單項訂閱Click事件，實現代碼如下：

windowsToolStripMenuItem.DropDownItemClicked += windowsToolStripMenuItem_DropDownItemClicked;void windowsToolStripMenuItem_DropDownItemClicked(object sender, ToolStripItemClickedEventArgs e){var menuItem = GetMenuItem(e.ClickedItem.Name);menuItem.Checked = true;var childForm = menuItem.Tag as Form;childForm.BringToFront();childForm.Focus();}private void CheckWindowsMenuItem(string menuName){var menuItem = GetMenuItem(menuName);if (menuItem != null){menuItem.Checked = true;}}

這樣就基本實現了在WINDOWS菜單項下顯示已打開的子窗口列表，并點擊指定的菜單項能夠切換當前活動的子窗口，但仍有一個不足的地方，那就是，當直接點擊子窗口來切換當前活動窗口時（說白了就是當點擊某個子窗口標題欄，該窗口就顯示在其它所有的子窗口最前面），WINDOWS菜單項下的子菜單勾選項沒有同步更新，一開始想到的是用Activated事件來進行處理，結果經測試發現有效，該Activated事件在點擊子窗口標題欄時并不會被觸發，所以只能換種方法，經過多次測試，發現當窗口從后面切換到前面時（稱為Z順序改變），子窗口就會發生重繪，從而觸發Paint方法，我們可以訂閱該事件，并進行處理，實現代碼如下：

private string currentChildFormName = null; //記錄當前活動子窗口名稱childForm.Paint += (s, e) => { var frm=s as Form;if (!frm.Name.Equals(currentChildFormName) && this.splitContainer1.Panel2.Controls[0].Equals(frm)) //當容器中第一個控件就是當前的窗口，則表明該窗口處于所有窗口之上{CheckWindowsMenuItem("menu_" + frm.Name);currentChildFormName = frm.Name;}};

最后貼出完整的實現代碼：

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace WindowsFormsApplication1{public partial class FormMain : Form{private int formCount = 0;private string currentChildFormName = null;public FormMain(){InitializeComponent();this.IsMdiContainer = true;this.splitContainer1.Panel2.ControlAdded += Panel2_ControlChanged;this.splitContainer1.Panel2.ControlRemoved += Panel2_ControlChanged;windowsToolStripMenuItem.DropDownItemClicked += windowsToolStripMenuItem_DropDownItemClicked;}void windowsToolStripMenuItem_DropDownItemClicked(object sender, ToolStripItemClickedEventArgs e){var menuItem = GetMenuItem(e.ClickedItem.Name);menuItem.Checked = true;var childForm = menuItem.Tag as Form;childForm.BringToFront();childForm.Focus();}private void FormMain_Load(object sender, EventArgs e){ShowChildForm<FormChild>();}private void ShowChildForm<TForm>() where TForm : Form, new(){TForm childForm = new TForm();childForm.Name = "frm" + Guid.NewGuid().ToString("N");childForm.Text = string.Format("Child Form -{0}", ++formCount);childForm.MdiParent = this;childForm.Parent = splitContainer1.Panel2;childForm.WindowState = FormWindowState.Maximized;childForm.Paint += (s, e) => { var frm=s as Form;if (!frm.Name.Equals(currentChildFormName) && this.splitContainer1.Panel2.Controls[0].Equals(frm)) //當容器中第一個控件就是當前的窗口，則表明該窗口處于所有窗口之上{CheckWindowsMenuItem("menu_" + frm.Name);currentChildFormName = frm.Name;}};childForm.Show();}private void CheckWindowsMenuItem(string menuName){var menuItem = GetMenuItem(menuName);if (menuItem != null){menuItem.Checked = true;}}void Panel2_ControlChanged(object sender, ControlEventArgs e){var frm = e.Control as Form;string menuName = "menu_" + frm.Name;bool exists = this.splitContainer1.Panel2.Controls.Contains(frm);if (exists){var menuItem = GetMenuItem(menuName);if (menuItem != null){menuItem.Checked = true;frm.BringToFront();frm.Focus();}else{windowsToolStripMenuItem.DropDownItems.Add(new ToolStripMenuItem() { Text = frm.Text, Name = menuName, Tag = frm, Checked = true });}}else{var menuItem = GetMenuItem(menuName);if (menuItem != null){windowsToolStripMenuItem.DropDownItems.Remove(menuItem);menuItem.Dispose();}}}private ToolStripMenuItem GetMenuItem(string menuName){var menuItems = windowsToolStripMenuItem.DropDownItems.Cast<ToolStripMenuItem>();menuItems.ToList().ForEach(m => m.Checked = false);return menuItems.Where(m => m.Name == menuName).SingleOrDefault();}private void newToolStripMenuItem_Click(object sender, EventArgs e){ShowChildForm<FormChild>();}}}

以下是系統自動生成的代碼：

namespace WindowsFormsApplication1{partial class FormMain{/// <summary>/// 必需的設計器變量。/// </summary>private System.ComponentModel.IContainer components = null;/// <summary>/// 清理所有正在使用的資源。/// </summary>/// <param name="disposing">如果應釋放托管資源，為 true；否則為 false。</param>protected override void Dispose(bool disposing){if (disposing && (components != null)){components.Dispose();}base.Dispose(disposing);}#region Windows 窗體設計器生成的代碼/// <summary>/// 設計器支持所需的方法 - 不要/// 使用代碼編輯器修改此方法的內容。/// </summary>private void InitializeComponent(){this.menuStrip1 = new System.Windows.Forms.MenuStrip();this.windowsToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();this.newToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();this.splitContainer1 = new System.Windows.Forms.SplitContainer();this.menuStrip1.SuspendLayout();((System.ComponentModel.ISupportInitialize)(this.splitContainer1)).BeginInit();this.splitContainer1.SuspendLayout();this.SuspendLayout();// // menuStrip1// this.menuStrip1.Items.AddRange(new System.Windows.Forms.ToolStripItem[] {this.windowsToolStripMenuItem,this.newToolStripMenuItem});this.menuStrip1.Location = new System.Drawing.Point(0, 0);this.menuStrip1.MdiWindowListItem = this.windowsToolStripMenuItem;this.menuStrip1.Name = "menuStrip1";this.menuStrip1.Size = new System.Drawing.Size(1069, 25);this.menuStrip1.TabIndex = 1;this.menuStrip1.Text = "menuStrip1";// // windowsToolStripMenuItem// this.windowsToolStripMenuItem.Name = "windowsToolStripMenuItem";this.windowsToolStripMenuItem.Size = new System.Drawing.Size(73, 21);this.windowsToolStripMenuItem.Text = "Windows";this.windowsToolStripMenuItem.Click += new System.EventHandler(this.windowsToolStripMenuItem_Click);// // newToolStripMenuItem// this.newToolStripMenuItem.Name = "newToolStripMenuItem";this.newToolStripMenuItem.Size = new System.Drawing.Size(46, 21);this.newToolStripMenuItem.Text = "New";this.newToolStripMenuItem.Click += new System.EventHandler(this.newToolStripMenuItem_Click);// // splitContainer1// this.splitContainer1.BackColor = System.Drawing.SystemColors.ActiveCaption;this.splitContainer1.Dock = System.Windows.Forms.DockStyle.Fill;this.splitContainer1.Location = new System.Drawing.Point(0, 25);this.splitContainer1.Name = "splitContainer1";// // splitContainer1.Panel2// this.splitContainer1.Panel2.BackColor = System.Drawing.SystemColors.ScrollBar;this.splitContainer1.Size = new System.Drawing.Size(1069, 526);this.splitContainer1.SplitterDistance = 356;this.splitContainer1.TabIndex = 2;// // FormMain// this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;this.ClientSize = new System.Drawing.Size(1069, 551);this.Controls.Add(this.splitContainer1);this.Controls.Add(this.menuStrip1);this.MainMenuStrip = this.menuStrip1;this.Name = "FormMain";this.Text = "FormMain";this.Load += new System.EventHandler(this.FormMain_Load);this.menuStrip1.ResumeLayout(false);this.menuStrip1.PerformLayout();((System.ComponentModel.ISupportInitialize)(this.splitContainer1)).EndInit();this.splitContainer1.ResumeLayout(false);this.ResumeLayout(false);this.PerformLayout();}#endregionprivate System.Windows.Forms.MenuStrip menuStrip1;private System.Windows.Forms.ToolStripMenuItem windowsToolStripMenuItem;private System.Windows.Forms.SplitContainer splitContainer1;private System.Windows.Forms.ToolStripMenuItem newToolStripMenuItem;}}

以下是效果演示截圖：