【发布时间】：2017-10-30 20:51:57
【问题描述】：
我正在尝试使用 C# 在 WinForms 中使用 DataGridView 创建一个自动完成列。我已经设法使用 DataGridView 的EditingControlShowing 事件让它工作并且工作正常。
但是，按照正常的自动完成文本框，过滤后的列表仅显示基于“开始于”的数据过滤。为了解决这个问题，我使用了来自here 的自动完成文本框，它允许使用自定义列表框进行子字符串搜索。
以这个自定义控件为基础，我创建了一个继承DataGridViewColumn的自定义控件。问题是 ListBox 控件不显示与 gridview 单元格内联。这是代码 -
public class DataGridViewAutoCompleteColumn : DataGridViewColumn
{
public DataGridViewAutoCompleteColumn()
: base(new DataGridViewAutoCompleteCell())
{
}
public override DataGridViewCell CellTemplate
{
get
{
return base.CellTemplate;
}
set
{
// Ensure that the cell used for the template is a DataGridViewAutoCompleteCell.
if (value != null &&
!value.GetType().IsAssignableFrom(typeof(DataGridViewAutoCompleteCell)))
{
throw new InvalidCastException("Must be a DataGridViewAutoCompleteCell");
}
base.CellTemplate = value;
}
}
}
public class DataGridViewAutoCompleteCell : DataGridViewTextBoxCell
{
public DataGridViewAutoCompleteCell()
: base()
{
// Use the short date format.
this.Style.Format = "d";
}
public override void InitializeEditingControl(int rowIndex, object
initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle)
{
// Set the value of the editing control to the current cell value.
base.InitializeEditingControl(rowIndex, initialFormattedValue, dataGridViewCellStyle);
AutoCompleteEditingControl ctl = DataGridView.EditingControl as AutoCompleteEditingControl;
ctl.AutoCompleteList = this.AutoCompleteList;
// Use the default row value when Value property is null.
if (this.Value == null)
{
ctl.Text = (string)this.DefaultNewRowValue;
}
else
{
ctl.Text = (string)this.Value;
}
}
public override Type EditType
{
get
{
// Return the type of the editing control that DataGridViewAutoCompleteCell uses.
return typeof(AutoCompleteEditingControl);
}
}
public override Type ValueType
{
get
{
// Return the type of the value that DataGridViewAutoCompleteCell contains.
return typeof(String);
}
}
public override object DefaultNewRowValue
{
get
{
// Use the current date and time as the default value.
return string.Empty;
// return DateTime.Now;
}
}
public List<String> AutoCompleteList { get; set; }
}
class AutoCompleteEditingControl : AutoCompleteTextbox, IDataGridViewEditingControl
{
DataGridView dataGridView;
private bool valueChanged = false;
int rowIndex;
public AutoCompleteEditingControl()
{
}
// Implements the IDataGridViewEditingControl.EditingControlFormattedValue
// property.
public object EditingControlFormattedValue
{
get
{
return this.Text;
}
set
{
if (value is String)
{
try
{
// This will throw an exception of the string is
// null, empty, or not in the format of a date.
this.Text = (String)value;
}
catch
{
// In the case of an exception, just use the
// default value so we're not left with a null
// value.
this.Text = String.Empty;
}
}
}
}
// Implements the
// IDataGridViewEditingControl.GetEditingControlFormattedValue method.
public object GetEditingControlFormattedValue(
DataGridViewDataErrorContexts context)
{
return EditingControlFormattedValue;
}
// Implements the
// IDataGridViewEditingControl.ApplyCellStyleToEditingControl method.
public void ApplyCellStyleToEditingControl(
DataGridViewCellStyle dataGridViewCellStyle)
{
this.Font = dataGridViewCellStyle.Font;
this.ForeColor = dataGridViewCellStyle.ForeColor;
this.BackColor = dataGridViewCellStyle.BackColor;
}
// Implements the IDataGridViewEditingControl.EditingControlRowIndex
// property.
public int EditingControlRowIndex
{
get
{
return rowIndex;
}
set
{
rowIndex = value;
}
}
// Implements the IDataGridViewEditingControl.EditingControlWantsInputKey
// method.
public bool EditingControlWantsInputKey(
Keys key, bool dataGridViewWantsInputKey)
{
// Let the DateTimePicker handle the keys listed.
switch (key & Keys.KeyCode)
{
case Keys.Left:
case Keys.Up:
case Keys.Down:
case Keys.Right:
case Keys.Home:
case Keys.End:
case Keys.PageDown:
case Keys.PageUp:
return true;
default:
return !dataGridViewWantsInputKey;
}
}
// Implements the IDataGridViewEditingControl.PrepareEditingControlForEdit
// method.
public void PrepareEditingControlForEdit(bool selectAll)
{
// No preparation needs to be done.
}
// Implements the IDataGridViewEditingControl
// .RepositionEditingControlOnValueChange property.
public bool RepositionEditingControlOnValueChange
{
get
{
return false;
}
}
// Implements the IDataGridViewEditingControl
// .EditingControlDataGridView property.
public DataGridView EditingControlDataGridView
{
get
{
return dataGridView;
}
set
{
dataGridView = value;
}
}
// Implements the IDataGridViewEditingControl
// .EditingControlValueChanged property.
public bool EditingControlValueChanged
{
get
{
return valueChanged;
}
set
{
valueChanged = value;
}
}
// Implements the IDataGridViewEditingControl
// .EditingPanelCursor property.
public Cursor EditingPanelCursor
{
get
{
return base.Cursor;
}
}
protected override void OnTextChanged(EventArgs eventargs)
{
// Notify the DataGridView that the contents of the cell
// have changed.
valueChanged = true;
this.EditingControlDataGridView.NotifyCurrentCellDirty(true);
base.OnTextChanged(eventargs);
}
}
请告知我在这里做错了什么。
【问题讨论】：
标签： c# winforms datagridview autocomplete datagridviewcolumn