winform Combobox出現System.Data.DataRowView的解決的方法

個人總結：

1.觸發了SelectedIndexChanged事件時：comboBox1.DataSource = dt;要放在comboBox1.SelectedIndex = 0;的上面

    
            comboBox1.DisplayMember = "hName";
            comboBox1.ValueMember = "hId";
            comboBox1.DataSource = dt;
            comboBox1.SelectedIndex = 0;

2.觸發了SelectedValueChanged事件時：comboBox1.DataSource = dt;要放在最上面

    comboBox1.DataSource = dt;
            comboBox1.DisplayMember = "hName";
            comboBox1.ValueMember = "hId";
            comboBox1.SelectedIndex = 0;

   並且在 comboBox1_SelectedValueChanged事件中還要加上推斷。

   if (comboBox1.SelectedValue.ToString() == "System.Data.DataRowView") return;
            string selectedHId = comboBox1.SelectedValue.ToString();