DataColumnCollection Class
Represents a collection of DataColumn objects for a DataTable.
Namespace: System.Data
Assembly: System.Data (in System.Data.dll)
The DataColumnCollection type exposes the following members.
| Name | Description | |
|---|---|---|
![]() ![]() | Count | Gets the total number of elements in a collection. (Inherited from InternalDataCollectionBase.) |
![]() ![]() | IsReadOnly | Gets a value that indicates whether the InternalDataCollectionBase is read-only. (Inherited from InternalDataCollectionBase.) |
![]() ![]() | IsSynchronized | Gets a value that indicates whether the InternalDataCollectionBase is synchonized. (Inherited from InternalDataCollectionBase.) |
![]() ![]() | Item[Int32] | Gets the DataColumn from the collection at the specified index. |
![]() ![]() | Item[String] | Gets the DataColumn from the collection with the specified name. |
![]() ![]() | SyncRoot | Gets an object that can be used to synchronize the collection. (Inherited from InternalDataCollectionBase.) |
| Name | Description | |
|---|---|---|
![]() ![]() | Add() | Creates and adds a DataColumn object to the DataColumnCollection. |
![]() ![]() | Add(DataColumn) | Creates and adds the specified DataColumn object to the DataColumnCollection. |
![]() ![]() | Add(String) | Creates and adds a DataColumn object that has the specified name to the DataColumnCollection. |
![]() ![]() | Add(String, Type) | Creates and adds a DataColumn object that has the specified name and type to the DataColumnCollection. |
![]() ![]() | Add(String, Type, String) | Creates and adds a DataColumn object that has the specified name, type, and expression to the DataColumnCollection. |
![]() ![]() | AddRange | Copies the elements of the specified DataColumn array to the end of the collection. |
![]() ![]() | CanRemove | Checks whether a specific column can be removed from the collection. |
![]() ![]() | Clear | Clears the collection of any columns. |
![]() ![]() | Contains | Checks whether the collection contains a column with the specified name. |
![]() ![]() | CopyTo(Array, Int32) | Copies all the elements of the current InternalDataCollectionBase to a one-dimensional Array, starting at the specified InternalDataCollectionBase index. (Inherited from InternalDataCollectionBase.) |
![]() ![]() | CopyTo(DataColumn[], Int32) | Copies the entire collection into an existing array, starting at a specified index within the array. |
![]() ![]() | Equals(Object) | Determines whether the specified object is equal to the current object. (Inherited from Object.) |
![]() ![]() | GetEnumerator | Gets an IEnumerator for the collection. (Inherited from InternalDataCollectionBase.) |
![]() ![]() | GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
![]() ![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() ![]() | IndexOf(DataColumn) | Gets the index of a column specified by name. |
![]() ![]() | IndexOf(String) | Gets the index of the column with the specific name (the name is not case sensitive). |
![]() ![]() | Remove(DataColumn) | Removes the specified DataColumn object from the collection. |
![]() ![]() | Remove(String) | Removes the DataColumn object that has the specified name from the collection. |
![]() ![]() | RemoveAt | Removes the column at the specified index from the collection. |
![]() ![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
| Name | Description | |
|---|---|---|
![]() ![]() | CollectionChanged | Occurs when the columns collection changes, either by adding or removing a column. |
The DataColumnCollection defines the schema of a DataTable, and determines what kind of data each DataColumn can contain. You can access the DataColumnCollection through the Columns property of the DataTable object.
The DataColumnCollection uses the Add and Remove methods to insert and delete DataColumn objects. Use the Count property to determine how many DataColumn objects are in the collection. Use the Contains method to verify whether a specified index or column name exists in the collection.
The following example iterates through a collection of DataColumn objects and prints various properties of each column in the collection.
private void PrintDataTableColumnInfo(DataTable table) { // Use a DataTable object's DataColumnCollection. DataColumnCollection columns = table.Columns; // Print the ColumnName and DataType for each column. foreach(DataColumn column in columns) { Console.WriteLine(column.ColumnName); Console.WriteLine(column.DataType); } }
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
