WinForms 设计器在更改控件的辅助功能时出错
本文关键字：功能 出错 控件 WinForms | 更新日期: 2023-09-27 18:34:20
我决定将 form1 设计器中的 listBox1 项更改为公共静态而不是私有，以便在另一个窗体上访问它。一旦我这样做了，它就出错了，不允许我更改表单本身的内容，只是在顶部告诉我这个错误
The variable 'listBox1' is either undeclared or was never assigned.
错误显示在以下行中
this.panel1.Controls.Add(listBox1);
设计师在下面为我的表格：
namespace Mercury.Forms
{
partial class Inside
{
/// <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.pictureBox1 = new System.Windows.Forms.PictureBox();
this.label1 = new System.Windows.Forms.Label();
this.label2 = new System.Windows.Forms.Label();
this.panel1 = new System.Windows.Forms.Panel();
Inside.listBox1 = new System.Windows.Forms.ListBox();
this.label3 = new System.Windows.Forms.Label();
this.panel2 = new System.Windows.Forms.Panel();
this.button1 = new System.Windows.Forms.Button();
((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
this.panel1.SuspendLayout();
this.SuspendLayout();
//
// pictureBox1
//
this.pictureBox1.BackColor = System.Drawing.Color.White;
this.pictureBox1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
this.pictureBox1.Image = global::Mercury.Properties.Resources.pooltablegodass_500x750;
this.pictureBox1.Location = new System.Drawing.Point(12, 11);
this.pictureBox1.Margin = new System.Windows.Forms.Padding(3, 4, 3, 4);
this.pictureBox1.Name = "pictureBox1";
this.pictureBox1.Size = new System.Drawing.Size(54, 48);
this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;
this.pictureBox1.TabIndex = 0;
this.pictureBox1.TabStop = false;
this.pictureBox1.Click += new System.EventHandler(this.pictureBox1_Click);
//
// label1
//
this.label1.AutoSize = true;
this.label1.Font = new System.Drawing.Font("Microsoft Sans Serif", 12F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
this.label1.ForeColor = System.Drawing.SystemColors.ButtonHighlight;
this.label1.Location = new System.Drawing.Point(74, 15);
this.label1.Name = "label1";
this.label1.Size = new System.Drawing.Size(82, 20);
this.label1.TabIndex = 1;
this.label1.Text = "Ash Smith";
this.label1.Click += new System.EventHandler(this.label1_Click);
//
// label2
//
this.label2.AutoSize = true;
this.label2.ForeColor = System.Drawing.SystemColors.ButtonHighlight;
this.label2.Location = new System.Drawing.Point(76, 37);
this.label2.Name = "label2";
this.label2.Size = new System.Drawing.Size(66, 13);
this.label2.TabIndex = 2;
this.label2.Text = "ashleytechie";
this.label2.Click += new System.EventHandler(this.label2_Click);
//
// panel1
//
this.panel1.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(64)))), ((int)(((byte)(64)))), ((int)(((byte)(64)))));
this.panel1.Controls.Add(this.button1);
this.panel1.Controls.Add(this.label3);
this.panel1.Controls.Add(listBox1);
this.panel1.Controls.Add(this.label2);
this.panel1.Controls.Add(this.label1);
this.panel1.Controls.Add(this.pictureBox1);
this.panel1.Location = new System.Drawing.Point(0, 0);
this.panel1.Margin = new System.Windows.Forms.Padding(3, 4, 3, 4);
this.panel1.Name = "panel1";
this.panel1.Size = new System.Drawing.Size(200, 348);
this.panel1.TabIndex = 3;
//
// listBox1
//
listBox1.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(64)))), ((int)(((byte)(64)))), ((int)(((byte)(64)))));
listBox1.BorderStyle = System.Windows.Forms.BorderStyle.None;
listBox1.Font = new System.Drawing.Font("Microsoft Sans Serif", 9F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
listBox1.ForeColor = System.Drawing.SystemColors.Window;
listBox1.FormattingEnabled = true;
listBox1.ItemHeight = 15;
listBox1.Items.AddRange(new object[] {
"Jake Simpson",
"Adam Jones",
"Jane Peters",
"Ashley Smith",
"Sam Smith",
"Joe Phelan",
"Peter Black",
"Tracy Bratford",
"Jamie Harrison",
"Peter Slims"});
listBox1.Location = new System.Drawing.Point(16, 107);
listBox1.Margin = new System.Windows.Forms.Padding(3, 4, 3, 4);
listBox1.Name = "listBox1";
listBox1.Size = new System.Drawing.Size(144, 180);
listBox1.TabIndex = 3;
listBox1.SelectedIndexChanged += new System.EventHandler(this.listBox1_SelectedIndexChanged);
//
// label3
//
this.label3.AutoSize = true;
this.label3.Font = new System.Drawing.Font("Microsoft Sans Serif", 14.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
this.label3.ForeColor = System.Drawing.SystemColors.Window;
this.label3.Location = new System.Drawing.Point(12, 79);
this.label3.Name = "label3";
this.label3.Size = new System.Drawing.Size(105, 24);
this.label3.TabIndex = 4;
this.label3.Text = "Contact List";
//
// panel2
//
this.panel2.Location = new System.Drawing.Point(205, 7);
this.panel2.Name = "panel2";
this.panel2.Size = new System.Drawing.Size(518, 335);
this.panel2.TabIndex = 4;
//
// button1
//
this.button1.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
this.button1.ForeColor = System.Drawing.SystemColors.ButtonHighlight;
this.button1.Location = new System.Drawing.Point(16, 304);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(170, 31);
this.button1.TabIndex = 5;
this.button1.Text = "Edit Profile";
this.button1.UseVisualStyleBackColor = true;
//
// Inside
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.BackColor = System.Drawing.SystemColors.ButtonHighlight;
this.ClientSize = new System.Drawing.Size(730, 347);
this.Controls.Add(this.panel2);
this.Controls.Add(this.panel1);
this.Margin = new System.Windows.Forms.Padding(3, 4, 3, 4);
this.Name = "Inside";
this.Text = "Inside";
this.Load += new System.EventHandler(this.Inside_Load);
((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
this.panel1.ResumeLayout(false);
this.panel1.PerformLayout();
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.PictureBox pictureBox1;
private System.Windows.Forms.Label label1;
private System.Windows.Forms.Label label2;
private System.Windows.Forms.Panel panel1;
public static System.Windows.Forms.ListBox listBox1;
private System.Windows.Forms.Label label3;
private System.Windows.Forms.Panel panel2;
private System.Windows.Forms.Button button1;
}
}
将其更改回以前的状态：（公共到私有，删除静态）
public static System.Windows.Forms.ListBox listBox1;
在窗体的代码隐藏中添加以下内容：（您不需要资源库，因为您不会从其他窗体创建新的列表框...我希望）
public ListBox MyListBox
{
get { return listBox1; }
}
现在，在其他窗体中（假设它们是由第一个窗体中的某个进程创建的），您将传递对窗体的当前实例的引用，其中包含 ListBox，以便您可以实际访问刚刚创建的公共属性：
public class SecondForm : Form
{
public SecondForm(FirstForm firstForm)
{
// do something with firstForm.MyListBox
}
}
最后，我想说的是，要小心你这样做的程度。能够访问彼此控件的表单对我来说似乎很混乱。如果您添加了有关您要通过此实现的目标的更多详细信息，我们也许能够提供更好的替代方案。
您的问题是您更改了设计器文件中的代码，因此listBox1现在是静态的。您无法执行此操作，因为设计器必须能够实例化 ListBox 的实例。
听起来您正在尝试做的是尝试从另一个表单修改列表框。您应该这样做的正确方法是通过属性。在你的代码（不是设计器代码，而是代码背后的代码）中，有这样的东西：
public ListBox MyListBox
{
get
{
return listBox1;
}
}
您不应更改.Designer.cs文件中的任何内容。如果要更改访问修饰符，则应通过"属性"窗口执行此操作。
话虽如此，您的public更改很好，您只是无法static。若要使设计器正常运行，窗体中的所有控件必须独立于每个实例化。
// what the code will look like when you change it from the Properties window
public System.Windows.Forms.ListBox listBox1;
如果您要制作ListBox static，您将像访问它一样
ListBox listbox = Inside.listBox1;
如果您有多个Inside形式漂浮，这没有多大意义。如果将其设置为非static，只要您有 Inside 类的实例，您仍然可以从所需的任何位置访问它。
Inside inside = new Inside();
ListBox listbox = inside.listBox1;