خوب پسر خوب TempDataSet = myDataSet.GetChanges();
واسه همینه دیگه. شما دیتاست رو به گرید پاس میدی و بعد با
myDataSet.HasChanges()
می فهمی که تغییرات داشتی یا نه بعد با GetChange تغییرات رو میخونی و داخل TempDataSet میریزی.
حالا با یه حلقه میتونی سطرهای TempDataSet رو مرور کنی. و بفهمی کدوم سطر حذف شده و کدوم سطر ویرایش شده
dr.RowState != DataRowState.Deleted
توضیحی که مایکروسافت داده اینه:
Creates a new
DataSet that contains a copy of all rows in the original
DataSet that have pending changes. Relationship constraints can cause additional unchanged rows to be added to the new
DataSet if the unchanged rows contain primary keys corresponding to foreign keys in the changed rows. The method returns null if there are no rows in the original
DataSet that have pending changes.
و نمونه پروژه هم اینه
private void DemonstrateMerge()
{
// Create a DataSet with one table, two columns,
// and three rows.
DataSet dataSet = new DataSet("dataSet");
DataTable table = new DataTable("Items");
DataColumn idColumn = new DataColumn("id",
Type.GetType("System.Int32"),"");
idColumn.AutoIncrement=true;
DataColumn itemColumn = new DataColumn("Item",
Type.GetType("System.Int32"),"");
// DataColumn array to set primary key.
DataColumn[] keyColumn= new DataColumn[1];
DataRow row;
// Create variable for temporary DataSet.
DataSet changesDataSet;
// Add RowChanged event handler for the table.
table.RowChanged+=new DataRowChangeEventHandler(
Row_Changed);
dataSet.Tables.Add(table);
table.Columns.Add(idColumn);
table.Columns.Add(itemColumn);
// Set primary key column.
keyColumn[0]= idColumn;
table.PrimaryKey=keyColumn;
// Add ten rows.
for(int i = 0; i <10;i++)
{
row=table.NewRow();
row["Item"]= i;
table.Rows.Add(row);
}
// Accept changes.
dataSet.AcceptChanges();
PrintValues(dataSet, "Original values");
// Change row values.
table.Rows[0]["Item"]= 50;
table.Rows[1]["Item"]= 111;
// Add one row.
row=table.NewRow();
row["Item"]=74;
table.Rows.Add(row);
// Insert code for error checking. Set one row in error.
table.Rows[1].RowError= "over 100";
PrintValues(dataSet, "Modified and New Values");
// If the table has changes or errors,
// create a subset DataSet.
if(dataSet.HasChanges(DataRowState.Modified |
DataRowState.Added)&& dataSet.HasErrors)
{
// Use GetChanges to extract subset.
changesDataSet = dataSet.GetChanges(
DataRowState.Modified|DataRowState.Added);
PrintValues(changesDataSet, "Subset values");
// Insert code to reconcile errors. In this case, reject changes.
foreach(DataTable changesTable in changesDataSet.Tables)
{
if (changesTable.HasErrors)
{
foreach(DataRow changesRow in changesTable.Rows)
{
//Console.WriteLine(changesRow["Item"]);
if((int)changesRow["Item",DataRowVersion.Current ]> 100)
{
changesRow.RejectChanges();
changesRow.ClearErrors();
}
}
}
}
// Add a column to the changesDataSet.
changesDataSet.Tables["Items"].Columns.Add(
new DataColumn("newColumn"));
PrintValues(changesDataSet, "Reconciled subset values");
// Merge changes back to first DataSet.
dataSet.Merge(changesDataSet, false,
System.Data.MissingSchemaAction.Add);
}
PrintValues(dataSet, "Merged Values");
}
private void Row_Changed(object sender, DataRowChangeEventArgs e)
{
Console.WriteLine("Row Changed " + e.Action.ToString()
+ "\table" + e.Row.ItemArray[0]);
}
private void PrintValues(DataSet dataSet, string label)
{
Console.WriteLine(label + "\n");
foreach(DataTable table in dataSet.Tables)
{
Console.WriteLine("TableName: " + table.TableName);
foreach(DataRow row in table.Rows)
{
foreach(DataColumn column in table.Columns)
{
Console.Write("\table " + row[column] );
}
Console.WriteLine();
}
}
}