C# 获取组合框的选定值
我将它们添加为:C# 获取组合框的选定值,c#,combobox,selecteditem,selectedvalue,selectedindexchanged,C#,Combobox,Selecteditem,Selectedvalue,Selectedindexchanged,我将它们添加为: public class ComboboxItem { public string Text { get; set; } public string Value { get; set; } public override string ToString() { return Text; } } private void comboBox1_SelectedIndexChanged(o
public class ComboboxItem {
public string Text { get; set; }
public string Value { get; set; }
public override string ToString() { return Text; }
}
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
int selectedIndex = comboBox1.SelectedIndex;
int selecteVal = (int)comboBox1.SelectedValue;
ComboboxItem selectedCar = (ComboboxItem)comboBox1.SelectedItem;
MessageBox.Show(String.Format("Index: [{0}] CarName={1}; Value={2}", selectedIndex, selectedCar.Text, selecteVal));
}
我一直得到一个NullReferenceException,不知道为什么。文本似乎显示得很好。试试这个:
ComboboxItem item = new ComboboxItem();
item.Text = cd.Name;
item.Value = cd.ID;
this.comboBox1.Items.Add(item);
// Code above
ServerInfo emailServer = (ServerInfo)cbServerName.SelectedItem;
mailClient.ServerName = emailServer.Value;
mailClient.ServerPort = emailServer.PortNo;
int selectedValue;
bool parseOK = Int32.TryParse(cmb.SelectedValue.ToString(), out selectedValue);
int selectedIndex = comboBox1.SelectedIndex;
comboBox1.SelectedItem.ToString();
int selectedValue = (int)comboBox1.Items[selectedIndex];
由于您使用的是
cmb,因此您将获得NullReferenceException
。SelectedValue
为空。comboBox
不知道自定义类ComboboxItem
的值是多少,因此您可以:
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
ComboBox cmb = (ComboBox)sender;
int selectedIndex = cmb.SelectedIndex;
int selectedValue = (int)cmb.SelectedValue;
ComboboxItem selectedCar = (ComboboxItem)cmb.SelectedItem;
MessageBox.Show(String.Format("Index: [{0}] CarName={1}; Value={2}", selectedIndex, selectedCar.Text, selecteVal));
}
或者更好地使用数据绑定,如:
ComboboxItem selectedCar = (ComboboxItem)comboBox2.SelectedItem;
int selecteVal = Convert.ToInt32(selectedCar.Value);
ComboboxItem1=新建ComboxItem();
项目1.Text=“测试”;
项目1.Value=“123”;
ComboboxItem2=新的ComboboxItem();
item2.Text=“test2”;
项目2.Value=“456”;
列表项=新列表{item1,item2};
this.comboBox1.DisplayMember=“Text”;
this.comboBox1.ValueMember=“Value”;
this.comboBox1.DataSource=项目;
我有一个类似的错误,我的类是
ComboboxItem item1 = new ComboboxItem();
item1.Text = "test";
item1.Value = "123";
ComboboxItem item2 = new ComboboxItem();
item2.Text = "test2";
item2.Value = "456";
List<ComboboxItem> items = new List<ComboboxItem> { item1, item2 };
this.comboBox1.DisplayMember = "Text";
this.comboBox1.ValueMember = "Value";
this.comboBox1.DataSource = items;
但我所做的是,我将我的类强制转换为ComboBox的SelectedItem属性。因此,我将拥有所选项的所有类属性
public class ServerInfo
{
public string Text { get; set; }
public string Value { get; set; }
public string PortNo { get; set; }
public override string ToString()
{
return Text;
}
}
我希望这对别人有帮助!
干杯 试试这个:
ComboboxItem item = new ComboboxItem();
item.Text = cd.Name;
item.Value = cd.ID;
this.comboBox1.Items.Add(item);
// Code above
ServerInfo emailServer = (ServerInfo)cbServerName.SelectedItem;
mailClient.ServerName = emailServer.Value;
mailClient.ServerPort = emailServer.PortNo;
int selectedValue;
bool parseOK = Int32.TryParse(cmb.SelectedValue.ToString(), out selectedValue);
int selectedIndex = comboBox1.SelectedIndex;
comboBox1.SelectedItem.ToString();
int selectedValue = (int)comboBox1.Items[selectedIndex];
SelectedValue
的问题是无法转换为整数。这是主要问题,因此使用以下代码片段将帮助您:
private void cmbLineColor_SelectedIndexChanged(object sender, EventArgs e)
{
DataRowView drv = (DataRowView)cmbLineColor.SelectedItem;
int selectedValue = (int)drv.Row.ItemArray[1];
}
试试这个:
ComboboxItem item = new ComboboxItem();
item.Text = cd.Name;
item.Value = cd.ID;
this.comboBox1.Items.Add(item);
// Code above
ServerInfo emailServer = (ServerInfo)cbServerName.SelectedItem;
mailClient.ServerName = emailServer.Value;
mailClient.ServerPort = emailServer.PortNo;
int selectedValue;
bool parseOK = Int32.TryParse(cmb.SelectedValue.ToString(), out selectedValue);
int selectedIndex = comboBox1.SelectedIndex;
comboBox1.SelectedItem.ToString();
int selectedValue = (int)comboBox1.Items[selectedIndex];
您必须将所选项目强制转换为自定义类(ComboboxItem) 试试这个:
int selectedIndex = comboBox1.SelectedIndex;
comboBox1.SelectedItem.ToString();
int selectedValue = (int)comboBox1.Items[selectedIndex];
}我认为,
ComboBoxItem
类只在WPF项目中可用。OP在他们的帖子中声明了它。奇怪的是System.Windows.Forms命名空间中没有一个…或者我错过了什么?在不使用数据源的情况下,对自定义项使用comboBox.SelectedValue不是很好吗?如果您使用数据源,则无法删除或向组合框项目添加项目。OP有一个C#问题。你的答案看起来像C++。