如何在Windows窗體中將組合框數據源綁定到窗體/列表框？

Question

我想單擊組合框時獲取表單作爲數據源。我怎麼能做到這一點。請給出建議。

Answer 1

我創建了一個繼承自標準Windows窗體組合框的PopupComboBox類。它有一個Title屬性，您可以設置當單擊組合時點擊彈出窗口中的哪個屬性。

public class PopupComboBox : ComboBox 
    { 
     private string title; 
     public string Title 
     { 
      get { return this.title; } 
      set { this.title = value; } 
     } 
     public PopupComboBox() : base() 
     { 

     } 

     public PopupComboBox (string title) 
      : base() 
     { 
      this.title = title; 
     } 

     protected override void OnMouseClick(MouseEventArgs e) 
     { 
      base.OnMouseClick(e); 

      // Show the popup form 
      var popup = new SelectItemForm(this.title, this); 
      var result = popup.ShowDialog(this); 

      if (result == DialogResult.OK) 
      { 
       // Select this item in the ComboBox 
       SelectedIndex = this.FindStringExact(popup.SelectedDisplay); 
      } 
     } 
    } 

當你點擊組合框時，會彈出一個窗體（SelectItemForm的源代碼如下）。它使用父PopupComboBox的DataSource，ValueMember和DisplayMember來使用組合中項目的列表填充ListView。當您單擊確定時，它會將所選項目保存在SelectedValue和SelectedDisplay屬性中，以便我們可以在窗體關閉時在ComboBox中選擇該項目。

public partial class SelectItemForm : Form 
    { 
     public object SelectedValue { get; private set; } 
     public string SelectedDisplay { get; private set; } 

     public SelectItemForm(string title, PopupComboBox parent) 
      :base() 
     { 
      InitializeComponent(); 

      this.Text = title; 

      // Add items to the list 
      foreach (var item in parent.Items) 
      { 
       // Get the display and value member properties for this combo box 
       // and use them for the Code/Name columns in the popup form 
       var props = item.GetType().GetProperties(); 
       var code = props.Where(p => p.Name == parent.ValueMember).Single().GetValue(item); 
       var name = props.Where(p => p.Name == parent.DisplayMember).Single().GetValue(item); 

       listView.Items.Add(new ListViewItem(
        new string[] { code.ToString(), name.ToString() })); 
      } 
     } 

     private void btnOk_Click(object sender, EventArgs e) 
     { 
      if (listView.SelectedItems != null && listView.SelectedItems.Count > 0) 
      { 
       SelectedValue = listView.SelectedItems[0].Text; 
       SelectedDisplay = listView.SelectedItems[0].SubItems[1].Text; 

       DialogResult = DialogResult.OK; 
      } 
      else 
      { 
       MessageBox.Show(this, "Select an item first", "Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); 
      } 
     } 

     private void btnCancel_Click(object sender, EventArgs e) 
     { 
      DialogResult = DialogResult.Cancel; 
     } 
    } 

這裏是形式，在這裏你可以看到我已經改變了什麼樣的屬性爲ListView看起來像它的設計部分：

partial class SelectItemForm 
    { 
     /// <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.listView = new System.Windows.Forms.ListView(); 
      this.btnOk = new System.Windows.Forms.Button(); 
      this.btnCancel = new System.Windows.Forms.Button(); 
      this.Code = ((System.Windows.Forms.ColumnHeader)(new System.Windows.Forms.ColumnHeader())); 
      this.Value = ((System.Windows.Forms.ColumnHeader)(new System.Windows.Forms.ColumnHeader())); 
      this.SuspendLayout(); 
      // 
      // listView 
      // 
      this.listView.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
      | System.Windows.Forms.AnchorStyles.Left) 
      | System.Windows.Forms.AnchorStyles.Right))); 
      this.listView.Columns.AddRange(new System.Windows.Forms.ColumnHeader[] { 
      this.Code, 
      this.Value}); 
      this.listView.FullRowSelect = true; 
      this.listView.GridLines = true; 
      this.listView.Location = new System.Drawing.Point(3, 3); 
      this.listView.MultiSelect = false; 
      this.listView.Name = "listView"; 
      this.listView.Size = new System.Drawing.Size(432, 170); 
      this.listView.TabIndex = 0; 
      this.listView.UseCompatibleStateImageBehavior = false; 
      this.listView.View = System.Windows.Forms.View.Details; 
      // 
      // btnOk 
      // 
      this.btnOk.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right))); 
      this.btnOk.Location = new System.Drawing.Point(272, 179); 
      this.btnOk.Name = "btnOk"; 
      this.btnOk.Size = new System.Drawing.Size(75, 23); 
      this.btnOk.TabIndex = 1; 
      this.btnOk.Text = "OK"; 
      this.btnOk.UseVisualStyleBackColor = true; 
      this.btnOk.Click += new System.EventHandler(this.btnOk_Click); 
      // 
      // btnCancel 
      // 
      this.btnCancel.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right))); 
      this.btnCancel.Location = new System.Drawing.Point(353, 179); 
      this.btnCancel.Name = "btnCancel"; 
      this.btnCancel.Size = new System.Drawing.Size(75, 23); 
      this.btnCancel.TabIndex = 2; 
      this.btnCancel.Text = "Cancel"; 
      this.btnCancel.UseVisualStyleBackColor = true; 
      this.btnCancel.Click += new System.EventHandler(this.btnCancel_Click); 
      // 
      // Code 
      // 
      this.Code.Text = "Code"; 
      this.Code.Width = 108; 
      // 
      // Value 
      // 
      this.Value.Text = "Name"; 
      this.Value.Width = 296; 
      // 
      // SelectItemForm 
      // 
      this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F); 
      this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; 
      this.ClientSize = new System.Drawing.Size(440, 214); 
      this.Controls.Add(this.btnCancel); 
      this.Controls.Add(this.btnOk); 
      this.Controls.Add(this.listView); 
      this.MaximizeBox = false; 
      this.MinimizeBox = false; 
      this.Name = "SelectItemForm"; 
      this.StartPosition = System.Windows.Forms.FormStartPosition.CenterParent; 
      this.Text = "Title"; 
      this.ResumeLayout(false); 

     } 

     #endregion 

     private System.Windows.Forms.ListView listView; 
     private System.Windows.Forms.Button btnOk; 
     private System.Windows.Forms.Button btnCancel; 
     private System.Windows.Forms.ColumnHeader Code; 
     private System.Windows.Forms.ColumnHeader Value; 
    } 

我已經還創建了一個小測試表單，您可以使用一小列產品測試PopupComboBox的功能。您需要將PopupComboBox添加到設計器中的窗體中，並將​​其稱爲comboPopup。

public partial class TestForm : Form 
    { 
     public class Product 
     { 
      public string Code { get; set; } 
      public string Name { get; set; } 
     } 

     public TestForm() 
     { 
      InitializeComponent(); 
     } 

     private void TestForm_Load(object sender, EventArgs e) 
     { 
      var products = new List<Product>(); 
      products.Add(new Product { Code = "0001", Name = "Coca Cola" }); 
      products.Add(new Product { Code = "0002", Name = "Mountain Dew" }); 
      products.Add(new Product { Code = "0003", Name = "Sprite Zero" }); 

      comboPopup.DataSource = products; 
      comboPopup.DisplayMember = "Name"; 
      comboPopup.ValueMember = "Code"; 

     } 
    }