我正在开发 Windows 窗体应用程序..
我有两个组合框..我将组合框 drop down style 属性更改为 DropDownList
保存数据后，我想清除组合框中的项目..所以我给出了这样的代码：
CmbDepartment.Text = "";
cmbvisitpurpose.Text = "";
但这并没有从我的组合框中清除所选项目..所以我更改了这样的代码：
cmbvisitpurpose.Items.RemoveAt(cmbvisitpurpose.SelectedIndex = -1)
CmbDepartment.Items.RemoveAt(CmbDepartment.SelectedIndex = -1)
这是从我的组合框中永久删除特定项目..如果我想获取组合框中的所有项目..我想加载页面..我只想清除所选项目.. 我该怎么做？
【问题讨论】：
这只会从组合框中删除，而不是从数据源中删除。
如果要保留项目，最好使用本地集合。
CmbDepartment.Items.Remove(CmbDepartment.SelectedItem);
这是一个关于如何将值分配给集合的示例
List<string> DepartmentsPermanent;
List<string> DepartmentsTemporary;
public Form1()
{
InitializeComponent();
DepartmentsPermanent = new List<string>();
DepartmentsPermanent.Add("EEE");
DepartmentsPermanent.Add("CSE");
DepartmentsPermanent.Add("E&I");
DepartmentsPermanent.Add("Mechanical");
comboBox1.DataSource = DepartmentsPermanent;
//here you assign the values to other List
DepartmentsTemporary = DepartmentsPermanent.ToList();
}
//Now if you have selected EEE from the list and you want to remove on selection
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
if (comboBox1.SelectedItem != null && DepartmentsTemporary != null)
{
DepartmentsTemporary.Remove(comboBox1.SelectedItem.ToString());
comboBox1.DataSource = DepartmentsTemporary;
}
//If you want to assign the default values again you can just assign the PermanentList
//comboBox1.DataSource = DepartmentsPermanent;
}
【讨论】：
如果要清除选中项，应将ComboBox.SelectedIndex属性设置为-1
【讨论】：