Class ListView

ListView View renders a scrollable list of data where each item can be activated to perform an action.
Inheritance
System.Object
Responder
View
ListView
Implements
System.IDisposable
System.ComponentModel.ISupportInitializeNotification
System.ComponentModel.ISupportInitialize
Inherited Members
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
Namespace: Terminal.Gui
Assembly: Terminal.Gui.dll
Syntax
public class ListView : View, IDisposable, ISupportInitializeNotification, ISupportInitialize
Remarks

The ListView displays lists of data and allows the user to scroll through the data. Items in the can be activated firing an event (with the ENTER key or a mouse double-click). If the AllowsMarking property is true, elements of the list can be marked by the user.

By default ListView uses System.Object.ToString() to render the items of any System.Collections.IList object (e.g. arrays, System.Collections.Generic.List<T>, and other collections). Alternatively, an object that implements the IListDataSource interface can be provided giving full control of what is rendered.

ListView can display any object that implements the System.Collections.IList interface. System.String values are converted into NStack.ustring values before rendering, and other values are converted into System.String by calling System.Object.ToString() and then converting to NStack.ustring .

To change the contents of the ListView, set the Source property (when providing custom rendering via IListDataSource) or call SetSource(IList) an System.Collections.IList is being used.

When AllowsMarking is set to true the rendering will prefix the rendered items with [x] or [ ] and bind the SPACE key to toggle the selection. To implement a different marking style set AllowsMarking to false and implement custom rendering.

Constructors

ListView()

Initializes a new instance of ListView. Set the Source property to display something.
Declaration
public ListView()

ListView(IList)

Initializes a new instance of ListView that will display the contents of the object implementing the System.Collections.IList interface, with relative positioning.
Declaration
public ListView(IList source)
Parameters
Type Name Description
System.Collections.IList source An System.Collections.IList data source, if the elements are strings or ustrings, the string is rendered, otherwise the ToString() method is invoked on the result.

ListView(IListDataSource)

Initializes a new instance of ListView that will display the provided data source, using relative positioning.
Declaration
public ListView(IListDataSource source)
Parameters
Type Name Description
IListDataSource source IListDataSource object that provides a mechanism to render the data. The number of elements on the collection should not change, if you must change, set the "Source" property to reset the internal settings of the ListView.

ListView(Rect, IList)

Initializes a new instance of ListView that will display the contents of the object implementing the System.Collections.IList interface with an absolute position.
Declaration
public ListView(Rect rect, IList source)
Parameters
Type Name Description
Rect rect Frame for the listview.
System.Collections.IList source An IList data source, if the elements of the IList are strings or ustrings, the string is rendered, otherwise the ToString() method is invoked on the result.

ListView(Rect, IListDataSource)

Initializes a new instance of ListView with the provided data source and an absolute position
Declaration
public ListView(Rect rect, IListDataSource source)
Parameters
Type Name Description
Rect rect Frame for the listview.
IListDataSource source IListDataSource object that provides a mechanism to render the data. The number of elements on the collection should not change, if you must change, set the "Source" property to reset the internal settings of the ListView.

Properties

AllowsMarking

Gets or sets whether this ListView allows items to be marked.
Declaration
public bool AllowsMarking { get; set; }
Property Value
Type Description
System.Boolean true if allows marking elements of the list; otherwise, false.
Remarks
If set to true, ListView will render items marked items with "[x]", and unmarked items with "[ ]" spaces. SPACE key will toggle marking.

AllowsMultipleSelection

If set to true allows more than one item to be selected. If false only allow one item selected.
Declaration
public bool AllowsMultipleSelection { get; set; }
Property Value
Type Description
System.Boolean

LeftItem

Gets or sets the left column where the item start to be displayed at on the ListView.
Declaration
public int LeftItem { get; set; }
Property Value
Type Description
System.Int32 The left position.

Maxlength

Gets the widest item.
Declaration
public int Maxlength { get; }
Property Value
Type Description
System.Int32

SelectedItem

Gets or sets the index of the currently selected item.
Declaration
public int SelectedItem { get; set; }
Property Value
Type Description
System.Int32 The selected item.

Source

Gets or sets the IListDataSource backing this ListView, enabling custom rendering.
Declaration
public IListDataSource Source { get; set; }
Property Value
Type Description
IListDataSource The source.
Remarks
Use SetSource(IList) to set a new System.Collections.IList source.

TopItem

Gets or sets the item that is displayed at the top of the ListView.
Declaration
public int TopItem { get; set; }
Property Value
Type Description
System.Int32 The top item.

Methods

AllowsAll()

Prevents marking if it's not allowed mark and if it's not allows multiple selection.
Declaration
public virtual bool AllowsAll()
Returns
Type Description
System.Boolean

MarkUnmarkRow()

Marks an unmarked row.
Declaration
public virtual bool MarkUnmarkRow()
Returns
Type Description
System.Boolean

MouseEvent(MouseEvent)

Method invoked when a mouse event is generated
Declaration
public override bool MouseEvent(MouseEvent me)
Parameters
Type Name Description
MouseEvent me
Returns
Type Description
System.Boolean true, if the event was handled, false otherwise.
Overrides

MoveDown()

Moves the selected item index to the next row.
Declaration
public virtual bool MoveDown()
Returns
Type Description
System.Boolean

MoveEnd()

Moves the selected item index to the last row.
Declaration
public virtual bool MoveEnd()
Returns
Type Description
System.Boolean

MoveHome()

Moves the selected item index to the first row.
Declaration
public virtual bool MoveHome()
Returns
Type Description
System.Boolean

MovePageDown()

Moves the selected item index to the previous page.
Declaration
public virtual bool MovePageDown()
Returns
Type Description
System.Boolean

MovePageUp()

Moves the selected item index to the next page.
Declaration
public virtual bool MovePageUp()
Returns
Type Description
System.Boolean

MoveUp()

Moves the selected item index to the previous row.
Declaration
public virtual bool MoveUp()
Returns
Type Description
System.Boolean

OnEnter(View)

Method invoked when a view gets focus.
Declaration
public override bool OnEnter(View view)
Parameters
Type Name Description
View view The view that is losing focus.
Returns
Type Description
System.Boolean true, if the event was handled, false otherwise.
Overrides

OnLeave(View)

Method invoked when a view loses focus.
Declaration
public override bool OnLeave(View view)
Parameters
Type Name Description
View view The view that is getting focus.
Returns
Type Description
System.Boolean true, if the event was handled, false otherwise.
Overrides

OnOpenSelectedItem()

Invokes the OnOpenSelectedItem event if it is defined.
Declaration
public virtual bool OnOpenSelectedItem()
Returns
Type Description
System.Boolean

OnSelectedChanged()

Invokes the SelectedChanged event if it is defined.
Declaration
public virtual bool OnSelectedChanged()
Returns
Type Description
System.Boolean

PositionCursor()

Positions the cursor in the right position based on the currently focused view in the chain.
Declaration
public override void PositionCursor()
Overrides

ProcessKey(KeyEvent)

If the view is focused, gives the view a chance to process the keystroke.
Declaration
public override bool ProcessKey(KeyEvent kb)
Parameters
Type Name Description
KeyEvent kb
Returns
Type Description
System.Boolean
Overrides
Remarks

Views can override this method if they are interested in processing the given keystroke. If they consume the keystroke, they must return true to stop the keystroke from being processed by other widgets or consumed by the widget engine. If they return false, the keystroke will be passed using the ProcessColdKey method to other views to process.

The View implementation does nothing but return false, so it is not necessary to call base.ProcessKey if you derive directly from View, but you should if you derive other View subclasses.

Redraw(Rect)

Redraws this view and its subviews; only redraws the views that have been flagged for a re-display.
Declaration
public override void Redraw(Rect bounds)
Parameters
Type Name Description
Rect bounds The bounds (view-relative region) to redraw.
Overrides
Remarks

Always use Bounds (view-relative) when calling Redraw(Rect), NOT Frame (superview-relative).

Views should set the color that they want to use on entry, as otherwise this will inherit the last color that was set globally on the driver.

Overrides of Redraw(Rect) must ensure they do not set Driver.Clip to a clip region larger than the region parameter.

ScrollDown(Int32)

Scrolls the view down.
Declaration
public virtual void ScrollDown(int lines)
Parameters
Type Name Description
System.Int32 lines Number of lines to scroll down.

ScrollLeft(Int32)

Scrolls the view left.
Declaration
public virtual void ScrollLeft(int cols)
Parameters
Type Name Description
System.Int32 cols Number of columns to scroll left.

ScrollRight(Int32)

Scrolls the view right.
Declaration
public virtual void ScrollRight(int cols)
Parameters
Type Name Description
System.Int32 cols Number of columns to scroll right.

ScrollUp(Int32)

Scrolls the view up.
Declaration
public virtual void ScrollUp(int lines)
Parameters
Type Name Description
System.Int32 lines Number of lines to scroll up.

SetSource(IList)

Sets the source of the ListView to an System.Collections.IList.
Declaration
public void SetSource(IList source)
Parameters
Type Name Description
System.Collections.IList source
Remarks
Use the Source property to set a new IListDataSource source and use custome rendering.

SetSourceAsync(IList)

Sets the source to an System.Collections.IList value asynchronously.
Declaration
public Task SetSourceAsync(IList source)
Parameters
Type Name Description
System.Collections.IList source
Returns
Type Description
System.Threading.Tasks.Task An item implementing the IList interface.
Remarks
Use the Source property to set a new IListDataSource source and use custom rendering.

Events

OpenSelectedItem

This event is raised when the user Double Clicks on an item or presses ENTER to open the selected item.
Declaration
public event Action<ListViewItemEventArgs> OpenSelectedItem
Event Type
Type Description
System.Action<ListViewItemEventArgs>

SelectedItemChanged

This event is raised when the selected item in the ListView has changed.
Declaration
public event Action<ListViewItemEventArgs> SelectedItemChanged
Event Type
Type Description
System.Action<ListViewItemEventArgs>

Implements

System.IDisposable
System.ComponentModel.ISupportInitializeNotification
System.ComponentModel.ISupportInitialize