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我在使用DataGridView時遇到了問題。我有一個包含5個表的數據集，這些表是從MySQL數據庫填充的。我有一個5個節點的TreeView。在每個TreeNode上，我將每個表綁定到DataGridView以更改產品列表。無法擺脫.NET DataGridView錯誤 - 索引沒有值
所以，如果我刪除或更新現有的DataGridView行並保存它有時我在下面得到錯誤，但有時它像一個魅力。我勒個去？
System.IndexOutOfRangeException：索引的 'x' 不爲 System.Windows.Forms.DataGridViewViewDataConnection.GetError（的Int32 rowIndex位置）具有在System.Windows.Forms.CurrencyManager.get_Item（的Int32索引） 值
這個錯誤後，我得到這個錯誤：
未處理的異常在此應用程序發生..：不設置到對象的實例 對象引用。
所以，我有2個按鈕：
1）保存按鈕：點擊它獲得從DataGridView的變化而變化，並更新數據庫：
try
{
/// Prisijungimas prie MySQL duombazes
var dbConnection = DBConnection.Instance();
dbConnection.DatabaseName = "amber";
/// Tikrinama, ar prisijungta
if (dbConnection.IsConnect())
{
/// Gaunami pakeitimai iš DataGridView
DataTable changes = ((DataTable)itemsDataGridView.DataSource).GetChanges();
if (changes != null)
{
DataTable columnsSchema = GetColumnNamesByTable(menuTreeView.SelectedNode.Tag.ToString());
/// Surašomi originalūs stulpelių pavadinimai
/// iš MySQL duombazės lentelės
int i = 0;
foreach (DataRow row in columnsSchema.Rows)
changes.Columns[i++].ColumnName = row.Field<String>("ColumnName");
/// Atliekami paketiimai MySQL duombazėje
if (itemsDataGridView.RowCount > 0 && CheckIfAllRowValuesExist(changes))
{
using (MySqlDataAdapter mySqlDataAdapter = new MySqlDataAdapter("SELECT * FROM " + menuTreeView.SelectedNode.Tag.ToString(), dbConnection.Connection))
{
MySqlCommandBuilder mcb = new MySqlCommandBuilder(mySqlDataAdapter);
mySqlDataAdapter.UpdateCommand = mcb.GetUpdateCommand();
int affectedRows = mySqlDataAdapter.Update(changes);
((DataTable)itemsDataGridView.DataSource).AcceptChanges();
/// Jei yra paveiktų eilučių, tai sėkmingai atnaujinta
if (affectedRows > 0)
{
MessageBox.Show("Sėkmingai atnaujinta", "Pranešimas",
MessageBoxButtons.OK,
MessageBoxIcon.Information);
}
}
}
else
{
MessageBox.Show("Prašome užpildyti visus laukus");
}
}
else
MessageBox.Show("Nebuvo ką atnaujinti", "Pranešimas",
MessageBoxButtons.OK,
MessageBoxIcon.Information);
}
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
finally
{
loadButton.PerformClick();
}
2）Load按鈕：它得到所有5個表從數據庫：
loadButton.Enabled = false;
/// Jei BackGroundWorker neužsiėmės pradedame darbą
if (getItemsBackgroundWorker.IsBusy == false)
getItemsBackgroundWorker.RunWorkerAsync();
/// Keičiame statusą
statusLabel.Text = "Gaunama";
3）
private void getItemsBackgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
GetKidsOrAdultsOrPetsAllRecords();
}
4）
public void GetKidsOrAdultsOrPetsAllRecords()
{
/// Jungiames prie MySQL duombazės
var dbConnection = DBConnection.Instance();
dbConnection.DatabaseName = "amber";
try
{
if (dbConnection.IsConnect())
{
string query = null;
query = "SELECT code as 'Kodas', quantity as 'Kiekis', color as 'Spalva', length as 'Ilgis', clasp as 'Užsegimas', thread as 'Siūlas', description as 'Aprašymas' FROM kids;" +
"SELECT code as 'Kodas', quantity as 'Kiekis', color as 'Spalva', length as 'Ilgis', clasp as 'Užsegimas', thread as 'Siūlas', description as 'Aprašymas' FROM adults;" +
"SELECT code as 'Kodas', quantity as 'Kiekis', color as 'Spalva', length as 'Ilgis', clasp as 'Užsegimas' FROM pets;" +
"SELECT code as 'Kodas', quantity as 'Kiekis', color as 'Spalva', image as 'Nuotrauka' FROM jewelry;" +
"SELECT code as 'Kodas', title as 'Pavadinimas', size as 'Dydis', weight as 'Svoris' FROM spareParts";
using (MySqlDataAdapter adapter = new MySqlDataAdapter(query, dbConnection.Connection))
{
dataSet.Clear();
adapter.Fill(dataSet);
if (dataSet.Tables.Count > 0)
{
/// Keičiame apatinį statusą
statusLabel.Text = "Visi įrašai gauti";
}
}
BeginInvoke((MethodInvoker)delegate
{
menuTreeView.Enabled = true;
});
}
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
statusLabel.Text = "Nepavyko gauti įrašų iš MySQL bazės";
}
finally
{
dbConnection.Close();
}
5）這就是我如何綁定物品的DataGridView：
private void menuTreeView_AfterSelect(object sender, TreeViewEventArgs e)
{
/// Tikriname, iš kurios MySQL lentelės imti duomenis
/// pagal TreeNode tag'ą
if (e.Node.Parent != null && (e.Node.Parent.Name == "wareHouseRoot"))
{
saveButton.Visible = true;
deleteButton.Visible = true;
addButton.Visible = true;
table = e.Node.Tag.ToString();
}
else
{
saveButton.Visible = false;
deleteButton.Visible = false;
addButton.Visible = false;
}
/// Padarome rezultatų GroupBox'ą nematomu
foreach (Control control in Controls)
{
if (control is GroupBox && (control.Name.ToString() != "searchGroupBox"))
control.Visible = false;
}
itemsDataGridView.DataSource = null;
/// Tikriname TreeNode pavadinimus ir
/// nustatome GroupBox'ams pavadinimus, matomumą
/// ir siunčiame užklausą gauti įrašams
switch (e.Node.Name)
{
case ("kidsNode"):
this.recordsGroupBox.Text = "Vaikų prekės";
this.recordsGroupBox.Visible = true;
itemsDataGridView.DataSource = dataSet.Tables[0];
break;
case ("adultsNode"):
this.recordsGroupBox.Text = "Suaugusiųjų prekės";
this.recordsGroupBox.Visible = true;
itemsDataGridView.DataSource = dataSet.Tables[1];
break;
case ("petsNode"):
this.recordsGroupBox.Text = "Gyvūnų prekės";
this.recordsGroupBox.Visible = true;
itemsDataGridView.DataSource = dataSet.Tables[2];
break;
case ("jewelryNode"):
this.recordsGroupBox.Text = "Juvelyrika";
this.recordsGroupBox.Visible = true;
itemsDataGridView.DataSource = dataSet.Tables[3];
itemsDataGridView.Columns[3].Visible = false;
jewelryGroupBox.Visible = true;
break;
case ("sparePartsNode"):
this.recordsGroupBox.Text = "Detalės";
this.recordsGroupBox.Visible = true;
this.itemsDataGridView.DataSource = dataSet.Tables[4];
break;
case ("amberRoot"):
this.controlPanelGroupBox.Visible = true;
break;
}
}
我卡在此問題，並不能找到解決辦法。我嘗試了在Google，Stackoverflow和其他論壇中找到的所有解決方案，但仍然無法擺脫它。
是線程問題，我猜。 datasource從工作線程修改，datasource綁定到dgv，dgv嘗試在UI線程中更新，如果它們不同步（這是隨機的或多或少）...繁榮，發生異常 – ASh
我可以填充MySQL記錄（約7000）沒有BackgroundWorker？如果沒有BackgroundWorker，應用程序似乎不會運行。 – Mantoshelis