datagridview重叠_datagridview绑定list_datagridview右键菜单(56)

15. 如何让TextBox类型的单元支持换行?

默认情况下，DataGridViewTextBoxCell不支持换行，这个可以由DataGridViewCellStyle的WrapMode属性来控制。 (如DataGridView.DefaultCellStyle.WrapMode)。将WrapMode 属性DataGridViewTriState枚举的三个取之一。

下面的代码示例使用DataGridView.DefaultCellStyle属性设置整个控件所包含的单元的WrapMode属性(即设置所有单元的换行模式)。

this.dataGridView1.DefaultCellStyle.WrapMode = DataGridViewTriState.True;

16. 如何使Image列不显示任何图像(字段为null时)?

默认情况下Image类型的列和单元将null转换为标准的“X”图像( )，将Image列的NullValue属性设置为null可使该列不显示任何图像。下面这行代码演示了如何设置Image列的NullValue属性。

this.dataGridViewImageColumn1.DefaultCellStyle.NullValue = null;

17. 如何能够在ComboBox类型的单元中输入数据?

private void dataGridView1_CellValidating(object sender,

DataGridViewCellValidatingEventArgs e)

{

if (e.ColumnIndex == comboBoxColumn.DisplayIndex)

{

if (!this.comboBoxColumn.Items.Contains(e.FormattedValue))

{

this.comboBoxColumn.Items.Add(e.FormattedValue);

}

}

}

private void dataGridView1_EditingControlShowing(object sender,

DataGridViewEditingControlShowingEventArgs e)

{

if (this.dataGridView1.CurrentCellAddress.X == comboBoxColumn.DisplayIndex)

{

ComboBox cb = e.Control as ComboBox;

if (cb != null)

{

cb.DropDownStyle = ComboBoxStyle.DropDown;

}

}

}

18. How do I have a combo box column display a sub set of data based upon the value of a different combo box column(TODO)?

Sometimes data that you want to display in the DataGridView has a relationship between two tables such as a category and subcategory. You want to let the user select the category and then choose between a subcategory based upon the category. This is possible with the DataGridView by using two combo box columns. To enable this, two versions of the filtered list (subcategory) needs to be created. One list has no filter applied while the other one will be filtered only when the user is editing a subcategory cell. Two lists are required due to the requirement described in 3.5.1 section that a combo box cells value must be in the items collection or else a DataError event is raised. In this case, since all combo box cells in the column use the same datasource if you filter the datasource for one row then a combo box cell in another row might not have its value visible in the datasource, thus causing a DataError event.

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