C# DataRow.ItemArray-Typ

DataRow.ItemArray-Eigenschaft
Ruft alle Werte dieser Zeile über ein Array ab oder legt sie fest.
Namespace: System.Data

Assembly: System.Data (in system.data.dll)

Codebeispiel:

private void CreateRowsWithItemArray()
{
    // Make a DataTable using the function below.
    DataTable dt = MakeTableWithAutoIncrement();
    DataRow relation;
    // Declare the array variable.
    object [] rowArray = new object[2];
    // Create 10 new rows and add to DataRowCollection.
    for(int i = 0; i <10; i++)
    {
        rowArray[0]=null;
        rowArray[1]= "item " + i;
        relation = dt.NewRow();
        relation.ItemArray = rowArray;
        dt.Rows.Add(relation);
    }
    PrintTable(dt);
}
 
private DataTable MakeTableWithAutoIncrement()
{
    // Make a table with one AutoIncrement column.
    DataTable table = new DataTable("table");
    DataColumn idColumn = new DataColumn("id", 
        Type.GetType("System.Int32"));
    idColumn.AutoIncrement = true;
    idColumn.AutoIncrementSeed = 10;
    table.Columns.Add(idColumn);

    DataColumn firstNameColumn = new DataColumn("Item", 
        Type.GetType("System.String"));
    table.Columns.Add(firstNameColumn);
    return table;
}
 
private void PrintTable(DataTable table)
{
    foreach(DataRow row in table.Rows)
    {
        foreach(DataColumn column in table.Columns)
        {
            Console.WriteLine(row[column]);
        }
    }
}

Ausnahme:

Ausnahmetyp	Bedingung
ArgumentException	Das Array ist größer als die Anzahl der Spalten in der Tabelle.
InvalidCastException	Die Werte im Array stimmen nicht mit dem DataType in ihrer entsprechenden DataColumn überein.
ConstraintException	Bearbeiten hat die Einschränkung aufgehoben.
ReadOnlyException	Ein Editor hat versucht, den Wert einer schreibgeschützten Spalte zu ändern.
NoNullAllowedException	编辑试图将空值放在 DataColumn 对象的 AllowDBNull 为 false 的列中。
DeletedRowInaccessibleException	该行已被删除。

DataRow.ItemArray 属性源代码实现：

public object[] ItemArray
{
	get
	{
		int defaultRecord = this.GetDefaultRecord();
		object[] array = new object[this._columns.Count];
		for (int i = 0; i < array.Length; i++)
		{
			DataColumn dataColumn = this._columns[i];
			array[i] = dataColumn[defaultRecord];
		}
		return array;
	}
	set
	{
		if (value == null)
		{
			throw ExceptionBuilder.ArgumentNull("ItemArray");
		}
		if (this._columns.Count < value.Length)
		{
			throw ExceptionBuilder.ValueArrayLength();
		}
		DataColumnChangeEventArgs dataColumnChangeEventArgs = null;
		if (this._table.NeedColumnChangeEvents)
		{
			dataColumnChangeEventArgs = new DataColumnChangeEventArgs(this);
		}
		bool flag = this.BeginEditInternal();
		for (int i = 0; i < value.Length; i++)
		{
			if (value[i] != null)
			{
				DataColumn dataColumn = this._columns[i];
				if (-1L != this.rowID && dataColumn.ReadOnly)
				{
					throw ExceptionBuilder.ReadOnly(dataColumn.ColumnName);
				}
				if (dataColumnChangeEventArgs != null)
				{
					dataColumnChangeEventArgs.InitializeColumnChangeEvent(dataColumn, value[i]);
					this._table.OnColumnChanging(dataColumnChangeEventArgs);
				}
				if (dataColumn.Table != this._table)
				{
					throw ExceptionBuilder.ColumnNotInTheTable(dataColumn.ColumnName, this._table.TableName);
				}
				if (-1L != this.rowID && dataColumn.ReadOnly)
				{
					throw ExceptionBuilder.ReadOnly(dataColumn.ColumnName);
				}
				if (this.tempRecord == -1)
				{
					this.BeginEditInternal();
				}
				object obj = (dataColumnChangeEventArgs != null) ? dataColumnChangeEventArgs.ProposedValue : value[i];
				if (obj == null)
				{
					if (dataColumn.IsValueType)
					{
						throw ExceptionBuilder.CannotSetToNull(dataColumn);
					}
					obj = DBNull.Value;
				}
				try
				{
					int proposedRecordNo = this.GetProposedRecordNo();
					dataColumn[proposedRecordNo] = obj;
				}
				catch (Exception e)
				{
					if (ADP.IsCatchableOrSecurityExceptionType(e) && flag)
					{
						this.CancelEdit();
					}
					throw;
				}
				this.LastChangedColumn = dataColumn;
				if (dataColumnChangeEventArgs != null)
				{
					this._table.OnColumnChanged(dataColumnChangeEventArgs);
				}
			}
		}
		this.EndEdit();
	}
}

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