C# DataRow.ItemArray 属性

黄舟
Release: 2017-02-21 11:03:14
Original
3817 people have browsed it

DataRow.ItemArray property
Gets or sets all the values ​​of this row through an array.
Namespace: System.Data

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

Code example:


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]);
        }
    }
}
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Exception:



##Exception typeConditions
ArgumentException

The array is greater than the number of columns in the table.

InvalidCastException

The value in the array does not match the DataType in its corresponding DataColumn.

ConstraintException

The editor broke the constraint.

ReadOnlyException

An editor attempted to change the value of a read-only column.

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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