Question

我正在使用Windows窗体应用程序..

我有两个组合框..我将我的组合框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。所以我改变了这样的代码：

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combbox中的所有项目..我要加载页面...我想要清除所选项目.. 我怎么能这样做？

Answer 1

这只会从组合框中删除，而不是从数据源中删除。

如果您想保留这些项目，请更好地使用本地收藏。

CmbDepartment.Items.Remove(CmbDepartment.SelectedItem);

以下是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;
    }

Answer 2

如果要清除所选项目，则应将ComboBox.SelectedIndex属性设置为-1

http://msdn.microsoft.com/en-us/library/system.windows.forms.combobox.selectedindex%28v=vs.110%29.aspx

从winform应用程序中的组合框中删除所选项目

2 个答案: