我遇到了以下问题：
我有一个包含Produkt和Gruppe的BindingLists的Core-Class作为公共静态。
类核心：
private static BindingList<Produkt> _produkte;
private static BindingList<Gruppe> _gruppen;
private static BindingList<Tag> _tage;
public Core() //operating class
{
Produkte = new BindingList<Produkt>();
Gruppen = new BindingList<Gruppe>();
Tage = new BindingList<Tag>();
}
Class Produkt：
private int _id; //Product attributes
private string _name;
private Gruppe _gruppe;
private double _kohlenhydrate_je_100g;
private double _eiweiss_je_100g;
private double _fett_je_100g;
private double _alkoholgehalt;
private double _kcal;
Class Gruppe：
private int _id; //group attributes. Each product has got 0-1 group
private string _name;
每个变量都有一个属性，包含公共Set＆amp;得到。 我需要在另一个表单DataGridView中显示BindingList _produkte，但我无法用Gruppe的所有项填充Combobox。 显示所有项目，并且显示的选定值在组合框中以及所有其他可能的值，但是我无法在我的DatagridViewComboBox中切换gruppe，也不允许我向Datagrid添加新行。
public Produktpflege()
{
InitializeComponent();
dataGridView1.Columns[0].ValueType = typeof(int);
dataGridView1.Columns[1].ValueType = typeof(string);
dataGridView1.Columns[2].ValueType = typeof(String); //changed Gruppe to string @ChetanRanpariya's comment, but no change in behaviour
dataGridView1.Columns[3].ValueType = typeof(double);
dataGridView1.Columns[4].ValueType = typeof(double);
dataGridView1.Columns[5].ValueType = typeof(double);
dataGridView1.Columns[6].ValueType = typeof(double);
dataGridView1.Columns[7].ValueType = typeof(double);
gridColGruppe.DataSource = Core.Gruppen.Select(item=>item.Name).ToList(); //get all items from ListBinding Gruppe
}
private void Produktpflege_Load(object sender, EventArgs e)
{
foreach (var v in Core.Produkte) //create a new line foreach Produkt in Datagrid
{
var gdvRow = new DataGridViewRow();
for (int i = 0; i < 8; i++) //create cells
{
if (i == 2) //Gruppe needs to be a combobox
gdvRow.Cells.Add(new DataGridViewComboBoxCell());
else //all other are only text
gdvRow.Cells.Add(new DataGridViewTextBoxCell());
}
gdvRow.Cells[0].Value = v.ID; //invisible for user
gdvRow.Cells[1].Value = v.Name;
gdvRow.Cells[2].Value = v.Gruppe.Name; //string with Gruppe-Name
gdvRow.Cells[3].Value = v.Kohlenhydrate_je_100g;
gdvRow.Cells[4].Value = v.Eiweiss_je_100g;
gdvRow.Cells[5].Value = v.Fett_je_100g;
gdvRow.Cells[6].Value = v.Alkoholgehalt_Prozent;
gdvRow.Cells[7].Value = v.KCAL; //readonly
dataGridView1.Rows.Add(gdvRow);
}
}
取消组合框中Gruppe的任何更改＆＃34; System.FormatException：DataGridViewComboBoxCell-Value无效。＆＃34;以及如果我只是加载表格并填写数据。
FormDesigner：
private void InitializeComponent()
{
this.components = new System.ComponentModel.Container();
this.dataGridView1 = new System.Windows.Forms.DataGridView();
this.gridColID = new System.Windows.Forms.DataGridViewTextBoxColumn();
this.gridColName = new System.Windows.Forms.DataGridViewTextBoxColumn();
this.gridColGruppe = new System.Windows.Forms.DataGridViewComboBoxColumn();
this.gridColKohlenhydrate_je_100g = new System.Windows.Forms.DataGridViewTextBoxColumn();
this.gridColEiweiss_je_100g = new System.Windows.Forms.DataGridViewTextBoxColumn();
this.gridColFett_je_100g = new System.Windows.Forms.DataGridViewTextBoxColumn();
this.gridColAlkoholgehalt_in_Prozent = new System.Windows.Forms.DataGridViewTextBoxColumn();
this.gridColKCAL = new System.Windows.Forms.DataGridViewTextBoxColumn();
this.gruppeBindingSource = new System.Windows.Forms.BindingSource(this.components);
((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).BeginInit();
((System.ComponentModel.ISupportInitialize)(this.gruppeBindingSource)).BeginInit();
this.SuspendLayout();
//
// dataGridView1
//
this.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
this.dataGridView1.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] {
this.gridColID,
this.gridColName,
this.gridColGruppe,
this.gridColKohlenhydrate_je_100g,
this.gridColEiweiss_je_100g,
this.gridColFett_je_100g,
this.gridColAlkoholgehalt_in_Prozent,
this.gridColKCAL});
this.dataGridView1.Location = new System.Drawing.Point(12, 58);
this.dataGridView1.Name = "dataGridView1";
this.dataGridView1.Size = new System.Drawing.Size(983, 192);
this.dataGridView1.TabIndex = 0;
this.dataGridView1.DataError += new System.Windows.Forms.DataGridViewDataErrorEventHandler(this.dataGridView1_DataError);
//
// gridColID
//
this.gridColID.HeaderText = "ID";
this.gridColID.Name = "gridColID";
this.gridColID.ReadOnly = true;
this.gridColID.Visible = false;
//
// gridColName
//
this.gridColName.HeaderText = "Name";
this.gridColName.Name = "gridColName";
//
// gridColGruppe
//
this.gridColGruppe.DataSource = this.gruppeBindingSource;
this.gridColGruppe.DisplayStyle = System.Windows.Forms.DataGridViewComboBoxDisplayStyle.ComboBox;
this.gridColGruppe.HeaderText = "Gruppe";
this.gridColGruppe.Name = "gridColGruppe";
this.gridColGruppe.ValueMember = "Name";
//
// gridColKohlenhydrate_je_100g
//
this.gridColKohlenhydrate_je_100g.HeaderText = "Kohlenhydrate_je_100g";
this.gridColKohlenhydrate_je_100g.Name = "gridColKohlenhydrate_je_100g";
//
// gridColEiweiss_je_100g
//
this.gridColEiweiss_je_100g.HeaderText = "Eiweiss_je_100g";
this.gridColEiweiss_je_100g.Name = "gridColEiweiss_je_100g";
//
// gridColFett_je_100g
//
this.gridColFett_je_100g.HeaderText = "Fett_je_100g";
this.gridColFett_je_100g.Name = "gridColFett_je_100g";
//
// gridColAlkoholgehalt_in_Prozent
//
this.gridColAlkoholgehalt_in_Prozent.HeaderText = "Alkoholgehalt_in_Prozent";
this.gridColAlkoholgehalt_in_Prozent.Name = "gridColAlkoholgehalt_in_Prozent";
//
// gridColKCAL
//
this.gridColKCAL.HeaderText = "KCAL";
this.gridColKCAL.Name = "gridColKCAL";
this.gridColKCAL.ReadOnly = true;
//
// gruppeBindingSource
//
this.gruppeBindingSource.DataSource = typeof(Kohlenhydrate_Datenbank.Gruppe);
//
// Produktpflege
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(1007, 262);
this.Controls.Add(this.button1);
this.Controls.Add(this.dataGridView1);
this.Name = "Produktpflege1";
this.Text = "Produktpflege";
this.Load += new System.EventHandler(this.Produktpflege_Load);
((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).EndInit();
((System.ComponentModel.ISupportInitialize)(this.gruppeBindingSource)).EndInit();
this.ResumeLayout(false);
}
#endregion
private System.Windows.Forms.DataGridView dataGridView1;
private DataGridViewTextBoxColumn gridColID;
private DataGridViewTextBoxColumn gridColName;
private DataGridViewComboBoxColumn gridColGruppe;
private BindingSource gruppeBindingSource;
private DataGridViewTextBoxColumn gridColKohlenhydrate_je_100g;
private DataGridViewTextBoxColumn gridColEiweiss_je_100g;
private DataGridViewTextBoxColumn gridColFett_je_100g;
private DataGridViewTextBoxColumn gridColAlkoholgehalt_in_Prozent;
private DataGridViewTextBoxColumn gridColKCAL;
如果我能在接下来的两周内得到你的帮助，我真的很高兴。请不要告诉我使用WPF，因为我需要它在Windows Forms中运行以支持Windows XP。