我在DataGridView单元格中有一个自定义控件。它是一个包含复选框项(CheckBoxComboBox)的组合框。这是问题所在: 1.输入一个CheckBoxComboBox并选择一些复选框项。 CheckboxComboBox的文本是已检查项目的csv字符串。 2.单击另一个是emtpy的CheckboxComboBox单元格(没有选中的项目)
结果:新单元格的文本包含旧单元格的文本。如果我单击CheckBoxComboBox单元格,然后单击非CheckBoxComboBox单元格,然后单击CheckBoxComboBox单元格,它可以正常工作。
我已经阅读并实现了基于此文档的自定义DataGridViewCell: How to: Host Controls in Windows Forms DataGridView Cells
当我通过自定义DataGridViewEditingControl进行调试时,似乎没有更新EditingControl.Tag。
所以我假设我有一个问题,EditControl正在被重用。
我尝试过的事情:
1。覆盖DataGridViewCell.Clone()
public override object Clone()
{
DataGridViewCheckBoxComboBoxCell checkBoxComboBoxCell = base.Clone() as DataGridViewCheckBoxComboBoxCell;
if (checkBoxComboBoxCell != null)
{
checkBoxComboBoxCell.Tag = this.Tag;
checkBoxComboBoxCell.Values = this.Values;
}
return checkBoxComboBoxCell;
}
2。覆盖DataGridViewCell.DetachEditingControl()
public override void DetachEditingControl()
{
DataGridView dataGridView = this.DataGridView;
if (dataGridView == null || dataGridView.EditingControl == null)
{
throw new InvalidOperationException("Cell is detached or its grid has no editing control.");
}
DataGridViewCheckBoxComboBoxCellEditingControl ctl = DataGridView.EditingControl as DataGridViewCheckBoxComboBoxCellEditingControl;
if (ctl != null)
{
//Just trying different things
ctl.EditingControlFormattedValue = String.Empty;
ctl.Text = string.Empty;
ctl.Tag = null;
ctl.Items.Clear();
}
base.DetachEditingControl();
}
知道如何解决这个问题吗?感谢。
编辑1
这是DataGridViewCheckBoxComboBoxColumn类
class DataGridViewCheckBoxComboBoxColumn : DataGridViewColumn
{
public override object Clone()
{
DataGridViewCheckBoxComboBoxColumn that = (DataGridViewCheckBoxComboBoxColumn)base.Clone();
return that;
}
private DataGridViewCheckBoxComboBoxCell _cell = null;
public DataGridViewCheckBoxComboBoxColumn()
{
_cell = new DataGridViewCheckBoxComboBoxCell();
base.CellTemplate = _cell;
}
public override DataGridViewCell CellTemplate
{
get
{
return base.CellTemplate;
}
set
{
// Ensure that the cell used for the template is a DateCell.
if (value != null &&
!value.GetType().IsAssignableFrom(typeof(DataGridViewCheckBoxComboBoxCell)))
{
throw new InvalidCastException("Must be a DataGridViewCheckBoxComboBoxColumn");
}
base.CellTemplate = value;
}
}
public string Values
{
set
{
_cell.Tag = value;
this.Tag = value;
}
get
{
return _cell.Tag.ToString();
}
}
}
编辑2 我的DataGridViewCheckBoxComboBoxCell重写了Paint()。当我在这个方法上放置一个断点时,单击该单元格时会调用它两次。第一次调用时,formattedValue为空。但是,第二次,formattedValue包含前一个checkboxcombobox单元格的错误字符串。
protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex,
DataGridViewElementStates cellState, object value, object formattedValue,
string errorText, DataGridViewCellStyle cellStyle,
DataGridViewAdvancedBorderStyle advancedBorderStyle,
DataGridViewPaintParts paintParts)
{}
为什么它会被调用两次,为什么第二次调用它包含正确单元格的错误格式化值?
答案 0 :(得分:1)
想出来。问题是在DetachEditingControl()中我需要清除CheckBoxItems。
public override void DetachEditingControl()
{
DataGridView dataGridView = this.DataGridView;
if (dataGridView == null || dataGridView.EditingControl == null)
{
throw new InvalidOperationException("Cell is detached or its grid has no editing control.");
}
DataGridViewCheckBoxComboBoxCellEditingControl ctl = DataGridView.EditingControl as DataGridViewCheckBoxComboBoxCellEditingControl;
if (ctl != null)
{
ctl.CheckBoxItems.Clear(); //Forgot to do this.
ctl.EditingControlFormattedValue = String.Empty;
}
base.DetachEditingControl();
}