Question

该方案与http://arsalantamiz.blogspot.com/2008/09/binding-datagridview-combobox-column.html几乎相同。但我不能让它在c＃...

上工作

我有两个表的mySql数据库：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（与“idprotocols”字段“链接”）

我想要得到的是一个包含名称的组合框，它将取代向导协议字段。接下来，如果用户更新“名称”组合框，则wizardProtocol将相应更改（因此我将能够相应地更新数据库中的更改）。

现在，在网上阅读了一些信息之后：我写了以下代码：

  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());
        }
    }

我正在尝试操纵DisplayMember属性，但是我失败了（我知道问题可能与我的数据绑定有关，但我无法弄明白......）

更新：由于答案，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

你做错的最明显的事情是你对datagridview和你的组合框使用相同的绑定源。如果你看一下你提供的例子，你会注意到他们创建了第二个绑定源productBindingSource。

所以你需要做的是创建一个bindingsource（让我们称之为wizardProtocolBindingSource），然后用协议表中的数据填充它。这将成为组合框列的数据源。

密钥代码如下所示：

// 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);

以上内容对您有用，但不知道数据集列的名称我不得不猜一点。

将绑定的组合框添加到datagridview

1 个答案: