这就是我为解决这个问题所做的工作,效果很好……
public class ImprovedComboBox : ComboBox
{
public ImprovedComboBox()
{
}
public object DataSource
{
get { return base.DataSource; }
set { base.DataSource = value; DetermineDropDownWidth(); }
}
public string DisplayMember
{
get { return base.DisplayMember; }
set { base.DisplayMember = value; DetermineDropDownWidth(); }
}
public string ValueMember
{
get { return base.ValueMember; }
set { base.ValueMember = value; DetermineDropDownWidth(); }
}
private void DetermineDropDownWidth()
{
int widestStringInPixels = 0;
foreach (Object o in Items)
{
string toCheck;
PropertyInfo pinfo;
Type objectType = o.GetType();
if (this.DisplayMember.CompareTo("") == 0)
{
toCheck = o.ToString();
}
else
{
pinfo = objectType.GetProperty(this.DisplayMember);
toCheck = pinfo.GetValue(o, null).ToString();
}
if (TextRenderer.MeasureText(toCheck, this.Font).Width > widestStringInPixels)
widestStringInPixels = TextRenderer.MeasureText(toCheck, this.Font).Width;
}
this.DropDownWidth = widestStringInPixels + 15;
}
}