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访问WinCE ComboBox下拉属性(.NET CF 2.0)

windows-ce compact-framework windows-mobile c#

2

PabloG · 技术社区 · 16 年前

我正在对表单控件实现自定义行为子分类,但无法访问ComboBox的DroppedDown属性。在帮助中,它应该在CF.NET 2.0中得到支持:

 using System;

 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Drawing;
 using System.Data;
 using System.Text;
 using System.Windows.Forms;

 namespace xCustomControls
 {
     public partial class xComboBox : System.Windows.Forms.ComboBox
     {
         private ComboBox comboBox1;

         public xComboBox()
         {
             InitializeComponent();
             this.KeyDown += new KeyEventHandler(this.KeyDownHandler);
         }

         private void KeyDownHandler(object sender, KeyEventArgs e)
         {
                // DroppedDown doesn't appear in the IntelliSense of ComboBox.
                // or this.comboBox1.
             if (((ComboBox)sender).DroppedDown)     // fail!
                 return;

             switch (e.KeyData)
             {
                 case Keys.Up:
                 case Keys.Enter:
                 case Keys.Down:
                     e.Handled = true;
                     this.Parent.SelectNextControl((Control)sender, e.KeyData != Keys.Up, true, true, true);

...

蒂亚,

1 回复 | 直到 16 年前

1

PabloG 16 年前

这个 DroppedDown 属性不在紧凑框架中,但可以使用以下内容:

public const int CB_GETDROPPEDSTATE = 0x0157;
public static bool GetDroppedDown(ComboBox comboBox)
{
 Message comboBoxDroppedMsg = Message.Create(comboBox.Handle, CB_GETDROPPEDSTATE, IntPtr.Zero, IntPtr.Zero);

 MessageWindow.SendMessage(ref comboBoxDroppedMsg);

 return comboBoxDroppedMsg.Result != IntPtr.Zero;
}

摘自: http://msdn.microsoft.com/en-us/netframework/bb735847.aspx