C＃ - 为填充数据绑定的组合框添加值？

Question

我试图将默认值添加到已填充数据源的组合框中。检查图像下方：

Windows form

值从Oracle数据库自动添加。现在我需要做的是再添加一个默认值，它将代表所有类别。

这里是一个设计师代码：

this.comboBox2.DataBindings.Add(new System.Windows.Forms.Binding("SelectedValue", this.vRSTEPROBLEMABindingSource, "NAZIV", true)); 
     this.comboBox2.DataSource = this.vRSTEPROBLEMABindingSource1; 
     this.comboBox2.DisplayMember = "NAZIV"; 
     this.comboBox2.FormattingEnabled = true; 
     this.comboBox2.Location = new System.Drawing.Point(89, 51); 
     this.comboBox2.Name = "comboBox2"; 
     this.comboBox2.Size = new System.Drawing.Size(173, 21); 
     this.comboBox2.TabIndex = 4; 
     this.comboBox2.Text = "Svi"; 
     this.comboBox2.ValueMember = "NAZIV"; 

Answer 1

我找到了解决方法，有没有办法将项目添加到combobox绑定数据。你可以做的是将项目填入List然后将它们添加到组合框。这里是一个代码：

  // your connection string + open connection 
      OracleConnection conn = new OracleConnection(global::IssueTracker.Properties.Settings.Default.ConnectionString); 
      conn.Open(); 

      // data adapter 
      OracleDataAdapter oa = new OracleDataAdapter("select naziv from vrsteproblema", conn); 
      DataSet ds = new DataSet(); 
      oa.Fill(ds, "vrsteproblema"); 

      // put entries into a list 
      List<string> comboNazivi = new List<string>(); 
      foreach (DataRow row in ds.Tables["vrsteproblema"].Rows) 
      { 
       comboNazivi.Add(row["naziv"].ToString()); 
      } 

      // add custom entry 
      comboBox2.Items.Add("Svi"); 
      // fill the rest from the list 
      for (var i = 0; i < comboNazivi.Count; i++) { 
       comboBox2.Items.Add(comboNazivi[i]); 
      } 

      // dont forget to close conn 
      conn.Close();