我在使用2列加载datagridview时遇到问题。 使用Datagridview和1个按钮的表单。
部门（文字） EmployeesByDpt（组合）
我有一个带有datagridview和Button（Load）的表单，当我按下load时，应该填充datagridview。 单击Employee Combo应显示属于特定部门的所有员工。
我似乎无法让它工作，下面就是我所做的，
有什么建议吗？目前没有任何显示。谢谢
代码（为了简单起见，我把所有内容放在一起）
public partial class Form2 : Form
{
Repository repository;
readonly DataGridViewTextBoxColumn colDepartment=new DataGridViewTextBoxColumn();
readonly DataGridViewComboBoxColumn colComboEmployeesByDpt = new DataGridViewComboBoxColumn();
public Form2()
{
InitializeComponent();
repository = new Repository();
SetupDataGridView();
}
private void SetupDataGridView()
{
dataGridView1.EditingControlShowing += OnEditingControlShowing;
dataGridView1.CellValueChanged += OnCellsValueChanged;
dataGridView1.AutoGenerateColumns = false;
colDepartment.DataPropertyName = "Name";
colDepartment.HeaderText = "Department Name";
colComboEmployeesByDpt.DataPropertyName = "Employees";
colComboEmployeesByDpt.HeaderText = "Employees";
colComboEmployeesByDpt.DisplayMember = "FullName";
//colComboEmployeesByDpt.DataSource = "FullName";
dataGridView1.Columns.AddRange(new DataGridViewColumn[] { colDepartment ,colComboEmployeesByDpt});
}
private void OnCellsValueChanged(object sender, DataGridViewCellEventArgs e)
{
}
private void OnEditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
if (dataGridView1.CurrentCell.ColumnIndex == colDepartment.Index)
{
var control = e.Control as DataGridViewComboBoxEditingControl;
if (control != null)
{
var bs = control.DataSource as BindingSource;
if (bs != null)
{
var comboBox = e.Control as ComboBox;
BindingList<Employee> employees = repository.GetEmployeeByDepartments(control.Text);
comboBox.DataSource = employees;
object employeeValue = dataGridView1.Rows[dataGridView1.CurrentCell.RowIndex].Cells[colComboEmployeesByDpt.Index].Value;
if (employeeValue == DBNull.Value || employeeValue == null)
if (dataGridView1.CurrentCell.Value != DBNull.Value && dataGridView1.CurrentCell.Value != null)
{
control.SelectedValue = dataGridView1.CurrentCell.Value;
}
}
}
}
}
private void btnLoad_Click(object sender, EventArgs e)
{
BindingList<Department> departments = repository.GetDepartments();
dataGridView1.DataSource = departments;
dataGridView1.Refresh();
}
}
public class Department
{
public Department()
{
Employees=new BindingList<Employee>();
}
public string Name { get; set; }
public BindingList<Employee> Employees { get; set; }
}
public class Employee
{
public string FullName { get; set; }
}
public class Repository
{
public BindingList<Department> GetDepartments()
{
var departments=new BindingList<Department>();
departments.Add(new Department{Name = "Food"});
departments.Add(new Department{Name = "Travel"});
departments.Add(new Department{Name = "Beauty"});
return departments;
}
public BindingList<Employee> GetEmployeeByDepartments(string name)
{
var employees = new BindingList<Employee>();
switch (name)
{
case "Food":
employees.Add(new Employee { FullName = "Jim Bloggs1" });
employees.Add(new Employee { FullName = "Jim Bloggs2" });
break;
case "Travel":
employees.Add(new Employee { FullName = "Marc Smith1" });
employees.Add(new Employee { FullName = "Marc Smith2" });
break;
case "Beauty":
employees.Add(new Employee { FullName = "Mario XXX1" });
employees.Add(new Employee { FullName = "Mario XXX2" });
break;
}
return employees;
}
}
答案 0 :(得分：0)
运行您的确切代码，我遇到了几个问题。以下说明将向您展示我为解决每个后续问题所做的工作，但有一个警告：最后，我无法从ComboBox进行选择而不更改DataGridView和Departments之间的绑定方法colComboEmployeesByDpt.DataPropertyName = "Employees";
并删除了一些提供的代码。
每行抛出ArgumentException
每一行都抛出异常：“DataGridViewComboBoxCell值无效。”更改以下行修复此问题：
colComboEmployeesByDpt.DataPropertyName = "Employee";
到
OnEditingControlShowing清空组合框
现在你会注意到ComboBox都是空的。在事件处理程序if statement中，第一个colComboEmployeesByDpt.Index应检查colDepartment.Index而不是if (bs != null)。但这还不够，因为control.Text总是假的。即使修复该检查，BindingList<Employee> employees = repository.GetEmployeeByDepartments(this.dataGridView1.CurrentRow.Cells[colDepartment.Index].Value.ToString());
也始终为空。相反，尝试：
ComboBox有了这个，您将看到每个ArgumentException都有正确的员工姓名列表。但是，ComboBox已经返回。尽我所能，这次我无法修复它。 （我怀疑colComboEmployeesByDpt.DisplayMember = "FullName";
private void OnEditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
...
}
项目列表始终为空，因此所选值为“无效”。）
答案 - 重组
为了让它发挥作用我做了几个核心的改变。我完全放弃了以下内容：
OnCellsValueChanged然后我添加了一个公共属性来记住Departments，手动绑定每一行的员工，并在部门名称更改时连接BindingList<Department> Departments { get; set; }
private void OnCellsValueChanged(object sender, DataGridViewCellEventArgs e)
{
if (e.ColumnIndex == colDepartment.Index)
{
this.Departments[e.RowIndex].Employees = repository.GetEmployeeByDepartments(this.dataGridView1.CurrentCell.EditedFormattedValue.ToString());
DataGridViewComboBoxCell cell = (DataGridViewComboBoxCell)this.dataGridView1.CurrentRow.Cells[colComboEmployeesByDpt.Index];
cell.DataSource = this.Departments[e.RowIndex].Employees;
}
}
private void btnLoad_Click(object sender, EventArgs e)
{
//this.dataGridView1.Rows.Clear(); // Needed if the button can be clicked repeatedly.
this.Departments = repository.GetDepartments();
foreach (Department department in this.Departments)
{
department.Employees = repository.GetEmployeeByDepartments(department.Name);
DataGridViewRow row = (DataGridViewRow)(dataGridView1.Rows[0].Clone());
DataGridViewTextBoxCell textCell = (DataGridViewTextBoxCell)(row.Cells[0]);
textCell.Value = department.Name;
DataGridViewComboBoxCell comboCell = (DataGridViewComboBoxCell)(row.Cells[1]);
comboCell.DataSource = department.Employees;
comboCell.DisplayMember = "FullName";
dataGridView1.Rows.Add(row);
}
}
以刷新列表：
{{1}}
这个解决方案对我有用。当我有空闲时间时，我将继续从困难的地方开始研究修复原始解决方案。希望现在有所帮助。