C# 动态更改Winforms组合框中项目的文本
我有一个WinformsC# 动态更改Winforms组合框中项目的文本,c#,.net,winforms,combobox,tostring,C#,.net,Winforms,Combobox,Tostring,我有一个Winforms组合框,其中包含自定义类的实例。当项目第一次添加到组合框的items集合时,ToString方法将对每个项目进行调用 但是,当用户更改应用程序运行的语言时,ToString方法的结果会更改 因此,我如何让组合框对所有项目再次调用ToString方法,而不必从组合框中删除所有项目并将其添加回?您应该能够通过调用RefreshItems()方法来实现这一点。是正确的。然而,正如前面提到的,子类是必要的。 RefreshItems是System.Windows.Forms.Co
组合框
,其中包含自定义类的实例。当项目第一次添加到组合框的items集合时,ToString
方法将对每个项目进行调用
但是,当用户更改应用程序运行的语言时,ToString
方法的结果会更改
因此,我如何让组合框
对所有项目再次调用ToString
方法,而不必从组合框中删除所有项目并将其添加回?您应该能够通过调用RefreshItems()
方法来实现这一点。是正确的。然而,正如前面提到的,子类是必要的。
RefreshItems是System.Windows.Forms.ComboBox的受保护方法
下面的表单应用程序提供了该行为的示例,以及更新组合框的RefreshItems方法:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace WindowsApplication1
{
public class Form1 : Form
{
private List<HelloWorld> helloWorlds;
#region Form1.Designer.cs
/// <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.comboBox1 = new RefreshingComboBox();
this.comboBox2 = new RefreshingComboBox();
this.label1 = new System.Windows.Forms.Label();
this.label2 = new System.Windows.Forms.Label();
this.button1 = new System.Windows.Forms.Button();
this.button2 = new System.Windows.Forms.Button();
this.button3 = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// comboBox1
//
this.comboBox1.FormattingEnabled = true;
this.comboBox1.Location = new System.Drawing.Point( 76, 12 );
this.comboBox1.Name = "comboBox1";
this.comboBox1.Size = new System.Drawing.Size( 115, 21 );
this.comboBox1.TabIndex = 0;
//
// comboBox2
//
this.comboBox2.FormattingEnabled = true;
this.comboBox2.Location = new System.Drawing.Point( 250, 12 );
this.comboBox2.Name = "comboBox2";
this.comboBox2.Size = new System.Drawing.Size( 218, 21 );
this.comboBox2.TabIndex = 1;
//
// label1
//
this.label1.AutoSize = true;
this.label1.Location = new System.Drawing.Point( 12, 15 );
this.label1.Name = "label1";
this.label1.Size = new System.Drawing.Size( 58, 13 );
this.label1.TabIndex = 2;
this.label1.Text = "Language:";
//
// label2
//
this.label2.AutoSize = true;
this.label2.Location = new System.Drawing.Point( 213, 15 );
this.label2.Name = "label2";
this.label2.Size = new System.Drawing.Size( 31, 13 );
this.label2.TabIndex = 3;
this.label2.Text = "Text:";
//
// button1
//
this.button1.Location = new System.Drawing.Point( 34, 42 );
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size( 75, 23 );
this.button1.TabIndex = 4;
this.button1.Text = "Set All";
this.button1.UseVisualStyleBackColor = true;
this.button1.Click += new System.EventHandler( this.button1_Click );
//
// button2
//
this.button2.Location = new System.Drawing.Point( 116, 42 );
this.button2.Name = "button2";
this.button2.Size = new System.Drawing.Size( 75, 23 );
this.button2.TabIndex = 5;
this.button2.Text = "Set Random";
this.button2.UseVisualStyleBackColor = true;
this.button2.Click += new System.EventHandler( this.button2_Click );
//
// button3
//
this.button3.Location = new System.Drawing.Point( 393, 42 );
this.button3.Name = "button3";
this.button3.Size = new System.Drawing.Size( 75, 23 );
this.button3.TabIndex = 6;
this.button3.Text = "Refresh!";
this.button3.UseVisualStyleBackColor = true;
this.button3.Click += new System.EventHandler( this.button3_Click );
//
// Form1
//
this.AutoScaleDimensions = new System.Drawing.SizeF( 6F, 13F );
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size( 556, 77 );
this.Controls.Add( this.button3 );
this.Controls.Add( this.button2 );
this.Controls.Add( this.button1 );
this.Controls.Add( this.label2 );
this.Controls.Add( this.label1 );
this.Controls.Add( this.comboBox2 );
this.Controls.Add( this.comboBox1 );
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout( false );
this.PerformLayout();
}
#endregion
private System.Windows.Forms.ComboBox comboBox1;
private System.Windows.Forms.ComboBox comboBox2;
private System.Windows.Forms.Label label1;
private System.Windows.Forms.Label label2;
private System.Windows.Forms.Button button1;
private System.Windows.Forms.Button button2;
private System.Windows.Forms.Button button3;
#endregion
public Form1()
{
InitializeComponent();
comboBox1.DataSource = new HelloWorld().GetLanguages();
helloWorlds = new List<HelloWorld>();
while ( helloWorlds.Count < 10 )
{
helloWorlds.Add( new HelloWorld() );
}
comboBox2.DataSource = helloWorlds;
}
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault( false );
Application.Run( new Form1() );
}
private void changeAllLanguages()
{
HelloWorld.LanguageValue newLang = (HelloWorld.LanguageValue) comboBox1.SelectedValue;
helloWorlds.ForEach(
delegate( HelloWorld hw )
{
hw.Language = newLang;
} );
}
private void changeRandomLanguage()
{
int index = new Random().Next( helloWorlds.Count );
HelloWorld.LanguageValue newLang = (HelloWorld.LanguageValue) comboBox1.SelectedValue;
helloWorlds[index].Language = newLang;
}
private void button1_Click( object sender, EventArgs e )
{
changeAllLanguages();
}
private void button2_Click( object sender, EventArgs e )
{
changeRandomLanguage();
}
private void button3_Click( object sender, EventArgs e )
{
(comboBox2 as RefreshingComboBox).RefreshItems();
}
}
public class RefreshingComboBox : System.Windows.Forms.ComboBox
{
public new void RefreshItem(int index)
{
base.RefreshItem(index);
}
public new void RefreshItems()
{
base.RefreshItems();
}
}
public class HelloWorld
{
public enum LanguageValue
{
English,
日本語,
Deutsch,
Français,
Český
}
private LanguageValue language;
public LanguageValue Language
{
get
{
return language;
}
set
{
language = value;
}
}
public Array GetLanguages()
{
return Enum.GetValues( typeof( LanguageValue ) );
}
Dictionary<LanguageValue, string> helloWorlds;
public HelloWorld()
{
helloWorlds = new Dictionary<LanguageValue, string>();
helloWorlds[LanguageValue.English] = "Hello, world!";
helloWorlds[LanguageValue.日本語] = "こんにちは、世界!";
helloWorlds[LanguageValue.Deutsch] = "Hallo, Welt!";
helloWorlds[LanguageValue.Français] = "Sallut, monde!";
helloWorlds[LanguageValue.Český] = "Ahoj svět!";
}
public override string ToString()
{
return helloWorlds[language];
}
}
}
使用系统;
使用System.Collections.Generic;
使用系统组件模型;
使用系统数据;
使用系统图;
使用系统文本;
使用System.Windows.Forms;
命名空间Windows应用程序1
{
公开课表格1:表格
{
私有列表helloWorlds;
#区域Form1.Designer.cs
///
///必需的设计器变量。
///
private System.ComponentModel.IContainer components=null;
///
///清理所有正在使用的资源。
///
///如果应释放托管资源,则为true;否则为false。
受保护的覆盖无效处置(布尔处置)
{
if(处理和(组件!=null))
{
组件。Dispose();
}
基地。处置(处置);
}
#区域Windows窗体设计器生成的代码
///
///设计器支持所需的方法-不修改
///此方法的内容与代码编辑器一起使用。
///
私有void InitializeComponent()
{
this.comboBox1=新的RefreshingComboBox();
this.combox2=新的刷新组合框();
this.label1=new System.Windows.Forms.Label();
this.label2=new System.Windows.Forms.Label();
this.button1=new System.Windows.Forms.Button();
this.button2=new System.Windows.Forms.Button();
this.button3=new System.Windows.Forms.Button();
这个.SuspendLayout();
//
//组合框1
//
this.comboBox1.FormattingEnabled=true;
this.comboBox1.Location=新系统图点(76,12);
this.comboBox1.Name=“comboBox1”;
this.comboBox1.Size=新系统图纸尺寸(115,21);
this.comboBox1.TabIndex=0;
//
//组合框2
//
this.comboBox2.FormattingEnabled=true;
this.comboBox2.Location=新系统.图纸.点(250,12);
this.comboBox2.Name=“comboBox2”;
this.comboBox2.Size=新系统图纸尺寸(218,21);
this.comboBox2.TabIndex=1;
//
//标签1
//
this.label1.AutoSize=true;
this.label1.Location=新系统图纸点(12,15);
this.label1.Name=“label1”;
this.label1.Size=新系统图纸尺寸(58,13);
this.label1.TabIndex=2;
this.label1.Text=“语言:”;
//
//标签2
//
this.label2.AutoSize=true;
this.label2.Location=新系统图纸点(213,15);
this.label2.Name=“label2”;
this.label2.Size=新系统图纸尺寸(31,13);
this.label2.TabIndex=3;
this.label2.Text=“Text:”;
//
//按钮1
//
this.button1.Location=新系统图纸点(34,42);
this.button1.Name=“button1”;
this.button1.Size=新系统图纸尺寸(75,23);
this.button1.TabIndex=4;
this.button1.Text=“全部设置”;
this.button1.UseVisualStyleBackColor=true;
this.button1.Click+=新系统.EventHandler(this.button1\u Click);
//
//按钮2
//
this.button2.Location=新系统图纸点(116,42);
this.button2.Name=“button2”;
this.button2.Size=新系统图纸尺寸(75,23);
this.button2.TabIndex=5;
this.button2.Text=“设置随机”;
this.button2.UseVisualStyleBackColor=true;
this.button2.Click+=新系统.EventHandler(this.button2\u Click);
//
//按钮3
//
this.button3.Location=新系统图纸点(393,42);
this.button3.Name=“button3”;
this.button3.Size=新系统图纸尺寸(75,23);
this.button3.TabIndex=6;
this.button3.Text=“刷新!”;
this.button3.UseVisualStyleBackColor=true;
this.button3.Click+=新系统.EventHandler(this.button3\u Click);
//
//表格1
//
此.AutoScaleDimensions=新系统.Drawing.SizeF(6F,13F);
this.AutoScaleMode=System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize=新系统.Drawing.Size(556,77);
this.Controls.Add(this.button3);
this.Controls.Add(this.button2);
this.Controls.Add(this.button1);
this.Controls.Add(this.label2);
this.Controls.Add(this.label1);
this.Controls.Add(this.comboBox2);
this.Controls.Add(this.comboBox1);
this.Name=“Form1”;
this.Text=“Form1”;
此选项为.resume布局(false);
public class RefreshingComboBox : ComboBox
{
public new void RefreshItem(int index)
{
base.RefreshItem(index);
}
public new void RefreshItems()
{
base.RefreshItems();
}
}
public class RefreshingToolStripComboBox : ToolStripComboBox
{
// We do not want "fake" selectedIndex change events etc, subclass that overide the OnIndexChanged etc
// will have to check InOnCultureChanged them selfs
private bool inRefresh = false;
public bool InRefresh { get { return inRefresh; } }
public void Refresh()
{
try
{
inRefresh = true;
// This is harder then it shold be, as I can't get to the Refesh method that
// is on the embebed combro box.
//
// I am trying to get ToString recalled on all the items
int selectedIndex = SelectedIndex;
object[] items = new object[Items.Count];
Items.CopyTo(items, 0);
Items.Clear();
Items.AddRange(items);
SelectedIndex = selectedIndex;
}
finally
{
inRefresh = false;
}
}
protected override void OnSelectedIndexChanged(EventArgs e)
{
if (!inRefresh)
{
base.OnSelectedIndexChanged(e);
}
}
}
/// <summary>
/// Recreates the items
/// </summary>
public static void RefreshItems(this ComboBox cb)
{
var selectedIndex = cb.SelectedIndex;
cb.SelectedIndex = -1;
MethodInfo dynMethod = cb.GetType().GetMethod("RefreshItems", BindingFlags.NonPublic | BindingFlags.Instance);
dynMethod.Invoke(cb, null);
cb.SelectedIndex = selectedIndex;
}