使用 DataGridView、DataTable 和 DataAdapter 的 CRUD 操作 - 无法向 DataGridView 添加新行 [英] CRUD Operations using DataGridView, DataTable and DataAdapter - Cannot add new row to DataGridView

问题描述

我正在尝试从 C# 界面网格视图向源表中插入新记录....但是，当我使用下面显示的按钮单击代码检索记录时......我在 gridview 中获取记录但没有插入新记录的选项(附上屏幕截图)......因为我可以从网格视图更新记录.

I'm trying to insert new records into the source table from the C# interface grid view.... But when I retrieve the records with the buttonclick code shown below... Im getting records in the gridview but no option for inserting new records(screen shot attached).. where as i can update the reocrds from the grid view.

是否有任何选项或属性可以在 gridview 中启用插入选项?

Is there any option or property for enabling the insertion option in the gridview ?

按钮点击代码:

private void RetrieveRules_button_Click(object sender, EventArgs e)
{
    this.dataGridView.DataSource = null;
    this.dataGridView.Rows.Clear();


    SqlCommand cmd1 = con.CreateCommand();
    cmd1.CommandType = CommandType.Text;
    cmd1.CommandText = @" Select TOP 1 * FROM " + schemaName + "[ERSBusinessLogic] ORDER BY ERSBusinessLogic_ID     DESC";
    con.Open();
    cmd1.ExecuteNonQuery();
    DataTable dt = new DataTable();
    SqlDataAdapter DA = new SqlDataAdapter(cmd1);
    DA.Fill(dt);
    dataGridView.DataSource = dt;
    con.Close();

}

谢谢

推荐答案

CRUD Operations using DataGridView, DataTable and DataAdapter

要让用户使用 DataGridView 添加、删除或编辑行:

CRUD Operations using DataGridView, DataTable and DataAdapter

To let the user add, delete or edit rows with DataGridView:

1. 设置 AllowUserToAddRows 属性为 true 或在 DataGridView Tasks 中，选中 Enable Adding
2. 设置 AllowUserToDeleteRows 属性为 true 或在 DataGridView Tasks 中，选中 Enable Deleting
3. 设置 ReadOnly 属性设置为 false 或在 DataGridView Tasks 中，选中 Enable Editing

1. Set AllowUserToAddRows property to true or in DataGridView Tasks, check Enable Adding
2. Set AllowUserToDeleteRows property to true or in DataGridView Tasks, check Enable Deleting
3. Set ReadOnly property to false or in DataGridView Tasks, check Enable Editing

让用户使用 SqlDataAdapter 保存更改:

To let the user save changes using a SqlDataAdapter:

1. 创建一个SqlDataAdapter 使用选择语句和连接字符串.
2. 您应该具有有效的 InsertCommand, DeleteCommand 和 UpdateCommand 用于您的数据适配器.使用 创建有效命令SqlCommandBuilder.
3. 将数据加载到 DataTable 使用数据适配器.
4. 设置数据表为DataGridView
的DataSource
5. 当您需要使用SqlDataAdapter.Update 通过将数据表传递给方法.

代码

DataTable table;
SqlDataAdapter adapter;
private void Form1_Load(object sender, EventArgs e)
{
    //Create adapter
    var connection = @"your connection string";
    var command = "SELECT * FROM Table1";
    adapter = new SqlDataAdapter(command, connection);

    //Create Insert, Update and Delete commands
    var builder = new SqlCommandBuilder(adapter);

    //Load data
    table = new DataTable();
    adapter.Fill(table);

    //Bind the grid to data
    this.dataGridView1.DataSource = table;

    //Enable add, delete and edit
    this.dataGridView1.AllowUserToAddRows = true;
    this.dataGridView1.AllowUserToDeleteRows = true;
    this.dataGridView1.ReadOnly = false;
}

private void saveButton_Click(object sender, EventArgs e)
{
    //Save Data
    adapter.Update(table);
}

private void Form1_FormClosed(object sender, FormClosedEventArgs e)
{
    adapter.Dispose();
}

注意

• 您不需要那个ExecuteNonQuery.您只需要一个连接字符串和一个命令文本.然后您可以创建一个数据适配器.然后你甚至不需要管理打开和关闭连接，数据适配器会管理它.
• 当您使用 SELECT TOP 1 * 加载数据时，如果添加数据并保存，下次加载数据时将看不到更新，因为您只加载了一条记录.

• You don't need that ExecuteNonQuery. You only need a connection string and a command text. Then you can create a data adapter. Then you even don't need to manage opening and closing the connection, data adapter manages it.
• When you load data using SELECT TOP 1 *, if you add data and save, you can't see updates next time you load the data because you load only a single record.

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