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QueryContinueDragEventArgs.KeyState Property

  • Reference

Definition

Namespace:
System.Windows.Forms
Assembly:
System.Windows.Forms.dll

Gets the current state of the SHIFT, CTRL, and ALT keys.

public:
 property int KeyState { int get(); };
public int KeyState { get; }
member this.KeyState : int
Public ReadOnly Property KeyState As Integer

Property Value

Int32

The current state of the SHIFT, CTRL, and ALT keys.

Examples

The following code example demonstrates the use of this member. In the example, an event handler reports on the occurrence of the Control.QueryContinueDrag event. This report helps you to learn when the event occurs and can assist you in debugging. To report on multiple events or on events that occur frequently, consider replacing MessageBox.Show with Console.WriteLine or appending the message to a multiline TextBox.

To run the example code, paste it into a project that contains an instance of a type that inherits from Control, such as a Button or ComboBox. Then name the instance Control1 and ensure that the event handler is associated with the Control.QueryContinueDrag event.

private void Control1_QueryContinueDrag(Object sender, QueryContinueDragEventArgs e) {

System.Text.StringBuilder messageBoxCS = new System.Text.StringBuilder();
messageBoxCS.AppendFormat("{0} = {1}", "KeyState", e.KeyState );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "EscapePressed", e.EscapePressed );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "Action", e.Action );
messageBoxCS.AppendLine();
MessageBox.Show(messageBoxCS.ToString(), "QueryContinueDrag Event" );
}

Private Sub Control1_QueryContinueDrag(sender as Object, e as QueryContinueDragEventArgs) _ 
     Handles Control1.QueryContinueDrag

    Dim messageBoxVB as New System.Text.StringBuilder()
    messageBoxVB.AppendFormat("{0} = {1}", "KeyState", e.KeyState)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "EscapePressed", e.EscapePressed)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "Action", e.Action)
    messageBoxVB.AppendLine()
    MessageBox.Show(messageBoxVB.ToString(),"QueryContinueDrag Event")

End Sub

Remarks

The bits that are set in the KeyState property identify the keys or mouse buttons that were pressed during the operation. For example, if the left mouse button is pressed, the first bit in the KeyState property is set. You can use the bitwise AND operator to test for a given key state.

The following table lists the bits that are set for a specified event.

Bit Key
1 The left mouse button.
2 The right mouse button.
4 The SHIFT key.
8 The CTL key.
16 The middle mouse button.
32 The ALT key.

By default, the QueryContinueDrag event sets Action to DragAction.Drop if KeyState indicates that the left, middle, or right mouse button is pressed.

Applies to

See also