The GetKey function returns an object which can be used to query information about keys. GetKey can be used in situations where the code is written against a general key, or even a general input object, as the return value from GetKey is of type FlatRedBall.Input.KeyReference, which implements FlatRedBall.Input.IPressableInput.

Introduction

The Keyboard class can be used for text input. Unfortunately, at the time of this writing the keyboard only understands the English keyboard. The GetStringTyped method returns the string that was typed during the last frame. It is possible for multiple keys to be pressed during a frame and the GetStringTyped method also considers whether the Shift key is pressed.

Code Example

The following code creates a Text object which displays the string typed.

Add the following using statement:

using FlatRedBall.Input;
using FlatRedBall.Graphics; // for Text
using Microsoft.Xna.Framework.Input; // for the Keys enum

in your Game class scope:

Text text;

Replace Initialize with the following:

protected override void Initialize()
{
    base.Initialize();     

    FlatRedBallServices.InitializeFlatRedBall(this, this.graphics);
    
    text = TextManager.AddText("Text:");
}

// Replace Update with the following:
protected override void Update(GameTime gameTime)
{
    FlatRedBallServices.Update(gameTime);

    text.DisplayText += InputManager.Keyboard.GetStringTyped();

    if (InputManager.Keyboard.KeyPushed(Keys.Enter))
        text.DisplayText = "";

    base.Update(gameTime);
}

Copy/Paste

GetStringTyped supports ctrl+c and ctrl+v for copy and paste; however, your game must be set to use [STAThread]. For more information, see this page.

Introduction

Get2DInput returns an I2DInput instance using the argument keys. This function can be used to abstract input, allowing the same input code to use keyboards and Xbox360GamePad instances. For more information see the page.

Code Example

The following code can be used to create an I2DInput instance:

Introduction

The Keyboard class provides functionality for getting input data from the physical keyboard. This class is automatically instantiated by and accessible through the InputManager. The Keyboard class is accessible both on a PC as well as on the Xbox 360.

Detecting Keyboard Activity

There are many ways to get data from the keyboard. The following section of code is a series of if-statements which could be used to detect input from the keyboard. Add the following using statements:

using FlatRedBall.Input;
using Microsoft.Xna.Framework.Input; // for the Keys enum

In your CustomActivity method:

void CustomActivity(bool firstTimeCalled)
{
   if(InputManager.Keyboard.KeyPushed(Keys.A))
   {
       // The A key was just pushed - down this frame, up last frame.
   }

   if(InputManager.Keyboard.KeyDown(Keys.B))
   {
      // The B key is down this frame.
   }

   if(InputManager.Keyboard.KeyReleased(Keys.C))
   {
      // The C key was just released - down last frame, up this frame.
   }

   if(InputManager.Keyboard.KeyTyped(Keys.D))
   {
      // The D key was just typed - either Pushed this frame or typed
      // again because the key was held down.
   }
}

Controlling Objects With the Keyboard

The Keyboard is commonly used to control objects like in-game characters and the Camera. The following code can be used to quickly control any PositionedObject Add the following using statement:

using FlatRedBall.Input;

Assuming positionedObject is a valid PositionedObject (or object inheriting from the PositionedObject class like a Sprite or Camera) add the following code in Update:

float velocityToApply = 10;
InputManager.Keyboard.ControlPositionedObject(positionedObject, velocityToApply);

For more control over input controlling movement, see the following entry on controlling the camera with the keyboard.

Back to Keyboard

Introduction

The ControlPositionedObject method is a method which can be used to move a PositionedObject with the arrow keys. this code is rarely used in final games, but can be very useful for learning how to use FlatRedBall and for quick prototypes.

Code Example

For an example, see this example on the main Keyboard page.

Introduction

The KeyPushed method returns whether the argument key was pressed this frame. This value will only return true for one frame when the key is first pushed.

Code Example

The following code will test to see if the Enter key has been pushed:

if(InputManager.Keyboard.KeyPushed(Keys.Space))
{
   // do something...
}

Introduction

The IgnoreKeyForOneFrame method marks the argument key as being ignored for the rest of the current frame. This is useful if your project has two live objects which are checking for a particular key, but you only want one of them to receive the key press.

Code Example

In this example we will consider a game screen which uses the Escape key to show a pause menu. Once the pause menu is visible, the Escape key will close it. We will assume that the Pause menu is an instance inside the Screen which has a Visible property (ImplementsIVisible in Glue). Code may look like this:

// In CustomActivity in GameScreen.cs (the custom code file)
if(InputManager.Keyboard.KeyPushed(Keys.Escape) && PauseMenuInstance.Visible == false)
{
   // The pause menu is not up, so let's show it then prevent anything else from using the Escape key
   PauseMenuInstance.Visible = true;
   InputManager.Keyboard.IgnoreKeyForOneFrame(Keys.Escape);
}

// In CustomActivity in PauseMenu.cs (the custom code file)
if(InputManager.Keyboard.KeyPushed(Keys.Escape) && this.Visible == true)
{
   this.Visible = false;
   InputManager.Keyboard.IgnoreKeyForOneFrame(Keys.Escape);
}

The code should consume the Escape key by calling IgnoreKeyForOneFrame to prevent both pieces of code from executing in the same frame.

Introduction

The KeyDown method is a method which returns whether a particular key is being held down. This method will return true if a key is pressed, and will continue to return true until the key has been released. This method can be used to perform every-frame actions such as setting the velocity of a character if the key is pressed.

Code Example

The following code will move a Sprite to the right if the Right arrow key is down:

// assumes SpriteInstance is a valid Sprite, and that it is not attached to anything:
if(FlatRedBall.Input.Keyboard.KeyDown(Keys.Right))
{
    // This will move it 10 units per second
    Sprite.X += TimeManager.SecondDifference * 10;
}

The Clear method clears out input from the Keyboard. After Clear is called, all Keyboard methods and properties will behave as if there was no keyboard activity this frame. This function is useful when implementing functionality that should consume input, and is commonly used with the IInputReceiver interface.