将绑定组合框添加到 datagridview

Question

该场景几乎与 http://arsalantamiz.blogspot 相同。 com/2008/09/binding-datagridview-combobox-column.html。但我无法让它在 c# 上工作...

我的 mySql 数据库有两个表： 1. 协议 2. pcapdata

在协议表中，我有两个字段： idprotocols 和 protocolName

在 pcaps 表中，我有 WizardProtocol （“链接”到 idprotocols 字段）

我想要得到的是一个包含将替换的名称的组合框向导协议字段。接下来，如果用户更新“名称”组合框，则向导协议将相应更改（因此我将能够相应更新数据库中的更改）。

现在，在阅读了网上的一些信息后：我编写了以下代码：

  public void Bind(ref DataGridView dataGridView)
    {
        try
        {

            mySqlDataAdapter = new MySqlDataAdapter(SELECT_ALL_PCAP, _con);
            mySqlCommandBuilder = new MySqlCommandBuilder(mySqlDataAdapter);

            mySqlDataAdapter.UpdateCommand = mySqlCommandBuilder.GetUpdateCommand();
            mySqlDataAdapter.DeleteCommand = mySqlCommandBuilder.GetDeleteCommand();
            mySqlDataAdapter.InsertCommand = mySqlCommandBuilder.GetInsertCommand();
            dataSet = new DataSet();
            mySqlDataAdapter.Fill(dataSet, "pcap");


            MySqlDataAdapter adp2 = new MySqlDataAdapter(SELECT_ALL_PROTOCOL, _con);
            MySqlCommandBuilder builder = new MySqlCommandBuilder(adp2);

            adp2.UpdateCommand = builder.GetUpdateCommand();
            adp2.DeleteCommand = builder.GetDeleteCommand();
            adp2.InsertCommand = builder.GetInsertCommand();
            adp2.Fill(dataSet, "protocol");


            bindingSource = new BindingSource();
            bindingSource.DataSource = dataSet;
            bindingSource.DataMember = "pcap";
            dataGridView.DataSource = bindingSource;


            dataGridView.Columns["length"].ReadOnly = true;
            dataGridView.Columns["length"].DefaultCellStyle.ForeColor = System.Drawing.Color.SandyBrown;
            dataGridView.AllowUserToAddRows = false;
            dataGridView.AllowUserToDeleteRows = false;


            DataGridViewComboBoxColumn colType = new DataGridViewComboBoxColumn();
            colType.HeaderText = "Type";
            colType.DropDownWidth = 90;
            colType.Width = 90;
            colType.DataPropertyName = "wizardProtocol";
            colType.DataSource = bindingSource;
            colType.DisplayMember = "protocolName";
            colType.ValueMember = "idprotocols";
            dataGridView.Columns.Insert(dataGridView.Columns.GetColumnCount(DataGridViewElementStates.None) - 1, colType);


        }
        catch (System.Exception e)
        {
            MessageBox.Show(e.ToString());
        }
    }

我试图操纵 DisplayMember 属性，但失败了（我知道问题可能出在我的数据绑定上，但我可以'不明白...）

更新：感谢您的回答，我正在重新附加固定代码

            mySqlDataAdapter = new MySqlDataAdapter(SELECT_ALL_PCAP, _con);
            mySqlCommandBuilder = new MySqlCommandBuilder(mySqlDataAdapter);

            mySqlDataAdapter.UpdateCommand = mySqlCommandBuilder.GetUpdateCommand();
            mySqlDataAdapter.DeleteCommand = mySqlCommandBuilder.GetDeleteCommand();
            mySqlDataAdapter.InsertCommand = mySqlCommandBuilder.GetInsertCommand();
            dataSet = new DataSet();
            mySqlDataAdapter.Fill(dataSet, "pcap");


            MySqlDataAdapter adp2 = new MySqlDataAdapter(SELECT_ALL_PROTOCOL, _con);
            MySqlCommandBuilder builder = new MySqlCommandBuilder(adp2);

            adp2.UpdateCommand = builder.GetUpdateCommand();
            adp2.DeleteCommand = builder.GetDeleteCommand();
            adp2.InsertCommand = builder.GetInsertCommand();
            adp2.Fill(dataSet, "protocol");



            bindingSource = new BindingSource();
            bindingSource.DataSource = dataSet;
            bindingSource.DataMember = "pcap";
            dataGridView.DataSource = bindingSource;
            dataGridView.AllowUserToAddRows = false;
            dataGridView.AllowUserToDeleteRows = false;


            DataGridViewComboBoxColumn colType = new DataGridViewComboBoxColumn();
            BindingSource wizardBindingSource = new BindingSource();
            wizardBindingSource.DataSource = dataSet; 
            wizardBindingSource.DataMember = "protocol";
            colType.HeaderText = "Type";
            colType.DropDownWidth = 90;
            colType.Width = 90;
            colType.DataPropertyName = "wizardProtocol";
            colType.DataSource = wizardBindingSource;
            colType.DisplayMember = "protocolName";
            colType.ValueMember = "idprotocols";
            dataGridView.Columns.Insert(dataGridView.Columns.GetColumnCount(DataGridViewElementStates.None) - 1, colType); 

Answer 1

您做错的最明显的事情是您对 datagridview 和组合框列使用相同的绑定源。如果您查看提供的示例，您会注意到他们创建了第二个绑定源productBindingSource。

因此，您需要做的是创建一个绑定源（我们称之为 WizardProtocolBindingSource），然后用协议表中的数据填充该绑定源。这将成为组合框列的数据源。

关键代码看起来像这样：

// You bind the datagridview just as before
// this dataset should have the idprotocols field which is your foreign key
// to the protocols table - you will probably want this to be hidden.
bindingSource = new BindingSource(); 
bindingSource.DataSource = dataSet; 
bindingSource.DataMember = "pcap"; 
dataGridView.DataSource = bindingSource; 

// hide the foreign key column
dataGridView.Columns["idProtocols"].Visible = false;

// here we populate your comboboxcolumn binding source
wizardProtocolBindingSource= new BindingSource(); 
// this dataset is from the protocols table
wizardProtocolBindingSource.DataSource = dataSet; 

// Add the combobox column
DataGridViewComboBoxColumn colType = new DataGridViewComboBoxColumn();      
colType.HeaderText = "Type";      
colType.DropDownWidth = 90;      
colType.Width = 90;      
colType.DataSource = wizardProtocolBindingSource;      
// The DataPropertyName refers to the foreign key column on the datagridview datasource
colType.DataPropertyName = "wizardProtocol";    
// The display member is the name column in the column datasource  
colType.DisplayMember = "protocolName";    
// The value member is the primary key of the protols table  
colType.ValueMember = "idprotocols";    
// I usually just add the column but you can insert if you need a particular position  
dataGridView.Columns.Add(colType);      

上面的代码应该适合您，尽管我不知道数据集列的名称，但我不得不猜测一下。