C# - 使用DataTable填充组合框

Question

我习惯使用Java,那里有大量的例子.由于各种原因,我不得不切换到C#并尝试在SharpDevelop中执行以下操作:

// Form has a menu containing a combobox added via SharpDevelop's GUI

// --- Variables
languages = new string[2];
languages[0] = "English";
languages[1] = "German";
DataSet myDataSet = new DataSet();

// --- Preparation
DataTable lTable = new DataTable("Lang");
DataColumn lName = new DataColumn("Language", typeof(string));
lTable.Columns.Add( lName );
for( int i=0; i<languages.Length; i++ ) {
    DataRow lLang = lTable.NewRow();
    lLang["Language"] = languages[i];
    lTable.Rows.Add(lLang);
}
myDataSet.Tables.Add(lTable);

// --- Handling the combobox
mnuActionLanguage.ComboBox.DataSource = myDataSet.Tables["Lang"].DefaultView;
mnuActionLanguage.ComboBox.DisplayMember = "Language";

人们会假设在下拉列表中看到一些值,但它是空的.请告诉我我做错了什么;(

编辑:mnuActionLanguage.ComboBox.DataBind()是我也在网上找到的,但它在我的情况下不起作用.

解

mnuActionLanguage.ComboBox.BindingContext = this.BindingContext;

最后解决了问题!

Answer 1

您需要设置ToolStripComboBox.ComboBox的绑定上下文.

这是我刚刚使用Visual Studio重新创建的代码的略微修改版本.在我的例子中,菜单项组合框被称为toolStripComboBox1.请注意设置绑定上下文的最后一行代码.

我注意到,如果组合在工具栏的可见区域中,则绑定在没有这个的情况下工作,但在下拉列表时则不然.你有同样的问题吗？

如果你不能让这个工作,请通过我的联系页面给我发一条线,然后我会发给你这个项目.您将无法使用SharpDevelop加载它,但将使用C#Express加载它.

var languages = new string[2];
languages[0] = "English";
languages[1] = "German";

DataSet myDataSet = new DataSet();

// --- Preparation
DataTable lTable = new DataTable("Lang");
DataColumn lName = new DataColumn("Language", typeof(string));
lTable.Columns.Add(lName);

for (int i = 0; i < languages.Length; i++)
{
    DataRow lLang = lTable.NewRow();
    lLang["Language"] = languages[i];
    lTable.Rows.Add(lLang);
}
myDataSet.Tables.Add(lTable);

toolStripComboBox1.ComboBox.DataSource = myDataSet.Tables["Lang"].DefaultView;
toolStripComboBox1.ComboBox.DisplayMember = "Language";

toolStripComboBox1.ComboBox.BindingContext = this.BindingContext;

Answer 2

string strConn = "Data Source=SEZSW08;Initial Catalog=Nidhi;Integrated Security=True";
SqlConnection Con = new SqlConnection(strConn);
Con.Open();
string strCmd = "select companyName from companyinfo where CompanyName='" + cmbCompName.SelectedValue + "';";
SqlDataAdapter da = new SqlDataAdapter(strCmd, Con);
DataSet ds = new DataSet();
Con.Close();
da.Fill(ds);
cmbCompName.DataSource = ds;
cmbCompName.DisplayMember = "CompanyName";
cmbCompName.ValueMember = "CompanyName";
//cmbCompName.DataBind();
cmbCompName.Enabled = true;

Answer 3

例如，我创建了一个表：

DataTable dt = new DataTable ();
dt.Columns.Add("Title", typeof(string));
dt.Columns.Add("Value", typeof(int));

将记录添加到表：

DataRow row = dt.NewRow();
row["Title"] = "Price"
row["Value"] = 2000;
dt.Rows.Add(row);

或者 ：

dt.Rows.Add("Price",2000);

最后 ：

combo.DataSource = dt;
combo.DisplayMember = "Title";
combo.ValueMember = "Value";