想传一个值到ComBoBox作为其默认值,我用selectedvalue不得行,请问有其他办法吗?下面是生成ComBoBox的代码
DataTable table1 = new DataTable();
table1.Columns.Add("bh");
table1.Columns.Add("mc");
DataRow newrow = table1.NewRow();
newrow["bh"] = "";
newrow["mc"] = "请选择";
table1.Rows.Add(newrow);
SqlCeCommand cmd = new SqlCeCommand("select bh,mc from " + tab, conn);
table1.Load(cmd.ExecuteReader());
ComBoBox1.DataSource = table1;
ComBoBox1.ValueMember = "bh";
ComBoBox1.DisplayMember = "mc";
DataTable table1 = new DataTable();
table1.Columns.Add("bh");
table1.Columns.Add("mc");
DataRow newrow = table1.NewRow();
newrow["bh"] = "";
newrow["mc"] = "请选择";
table1.Rows.Add(newrow);
SqlCeCommand cmd = new SqlCeCommand("select bh,mc from " + tab, conn);
table1.Load(cmd.ExecuteReader());
ComBoBox1.DataSource = table1;
ComBoBox1.ValueMember = "bh";
ComBoBox1.DisplayMember = "mc";
this.comboBox1.DataSource = dtway;
DataRow dr = dtway.NewRow();
dr["CName"] = "";
dr["CT_ID"] = string.Empty;
dtway.Rows.InsertAt(dr, 0);
this.comboBox1.DisplayMember = "CName";
this.comboBox1.ValueMember = "CT_ID";
this.comboBox1.SelectedIndex = 0;
这个是默认为空选项!
然后 this.comboBox1.SelectedIndex = 0;
设置selectedindex为下标中的任意一个就可以了
1为第二个,依此类推
for (int i = 0; i < combobox.Items.Count; i++)
{
if (combobox.Items[i] == "你定义的默认值") //这个项的索引未必是0,是多少就是多少,反正用它做默认值就可以了。
{
combobox.SelectedIndex = i;
break;
}
}
DataTable table1 = new DataTable();
table1.Columns.Add("bh");
table1.Columns.Add("mc");
DataRow newrow = table1.NewRow();
newrow["bh"] = "";
newrow["mc"] = "请选择";
table1.Rows.Add(newrow);
SqlCeCommand cmd = new SqlCeCommand("select bh,mc from " + tab, conn);
table1.Load(cmd.ExecuteReader());
ComBoBox1.DataSource = table1;
ComBoBox1.ValueMember = "bh";
ComBoBox1.DisplayMember = "mc";你这段代码没有问题吗?
ComboBox在绑定的时候,要先设定其ValueMember和DisplayMember,再指定DataSource的。
{
SqlConnection Conn1 = getConnection();
Conn1.Open();
SqlDataAdapter da = new SqlDataAdapter("select ClassNumber , ClassName from Class , Conn1);
DataSet ds = new DataSet();
da.Fill(ds, "Class");
comboBox2.DisplayMember = "ClassName";
comboBox2.ValueMember = "ClassNumber";
comboBox2.DataSource = ds.Tables[0].DefaultView;
SpecialtyName = comboBox1.Text.Trim();
Conn1.Close();
}