Flash / Flex / ActionScript/Development/KeyboardEvent
Содержание
- 1 Converting user input to uppercase
- 2 Determining the Character Associated with a Key
- 3 Handling keyboard events for a particular object
- 4 Handling keyboard events globally
- 5 KeyboardEvent Basics
- 6 Listen for the keyDown event and traces out the character code for that key.
- 7 Multilocation keys
- 8 Reference key code with Keyboard.ESCAPE
- 9 Retrieving a pressed key"s key code through KeyboardEvent.KEY_DOWN event
- 10 Understanding keyCodes
- 11 Up / Left Sensor
Converting user input to uppercase
<source lang="java">
package {
import flash.display.*;
import flash.events.*;
import flash.text.*;
public class Main extends Sprite {
private var inputfield:TextField = new TextField( );
public function Main() {
inputfield.text = "";
inputfield.width = 150;
inputfield.height = 30;
inputfield.border = true;
inputfield.background = true;
inputfield.type = TextFieldType.INPUT;
addChild(inputfield);
inputfield.addEventListener(TextEvent.TEXT_INPUT, textInputListener);
}
private function textInputListener (e:TextEvent):void {
e.preventDefault( );
inputfield.replaceText(inputfield.caretIndex,
inputfield.caretIndex,
e.text.toUpperCase( ));
var newCaretIndex:int = inputfield.caretIndex + e.text.length;
inputfield.setSelection(newCaretIndex, newCaretIndex);
}
}
}
</source>
Determining the Character Associated with a Key
<source lang="java">
package {
import flash.display.*;
import flash.events.*;
import flash.text.*;
import flash.ui.*;
public class Main extends Sprite {
private var keyoutput:TextField = new TextField( );
public function Main() {
keyoutput.text = "Press any key...";
keyoutput.autoSize = TextFieldAutoSize.LEFT;
keyoutput.border = true;
keyoutput.background = true;
addChild(keyoutput);
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDownListener);
}
private function keyDownListener (e:KeyboardEvent):void {
keyoutput.text = "The key code for the key you pressed is: "
+ e.keyCode + "\n";
keyoutput.appendText("The character code for the key you pressed is: "
+ e.charCode + "\n");
keyoutput.appendText("The character for the key you pressed is: "
+ String.fromCharCode(e.charCode));
}
}
}
</source>
Handling keyboard events for a particular object
<source lang="java">
package {
import flash.display.*;
import flash.events.*;
public class Main extends Sprite {
public function Main( ) {
var rect1:Sprite = new Sprite( );
rect1.graphics.lineStyle(1);
rect1.graphics.beginFill(0x0000FF);
rect1.graphics.drawRect(0, 0, 75, 75);
rect1.tabEnabled = true;
var rect2:Sprite = new Sprite( );
rect2.graphics.lineStyle(1);
rect2.graphics.beginFill(0x0000FF);
rect2.graphics.drawRect(0, 0, 75, 75);
rect2.x = 200;
rect2.tabEnabled = true;
addChild(rect1);
addChild(rect2);
rect1.addEventListener(KeyboardEvent.KEY_DOWN, rect1KeyDownListener);
rect2.addEventListener(KeyboardEvent.KEY_DOWN, rect2KeyDownListener);
}
private function rect1KeyDownListener (e:KeyboardEvent):void {
Sprite(e.target).x += 10;
}
private function rect2KeyDownListener (e:KeyboardEvent):void {
Sprite(e.target).rotation += 10;
}
}
}
</source>
Handling keyboard events globally
<source lang="java">
package {
import flash.display.*;
import flash.events.*;
public class Main extends Sprite {
public function Main ( ) {
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDownListener);
}
private function keyDownListener (e:KeyboardEvent):void {
trace("A key was pressed.");
}
}
}
</source>
KeyboardEvent Basics
<source lang="java">
package {
import flash.display.Sprite;
import flash.events.KeyboardEvent;
public class Main extends Sprite
{
private var sprite:Sprite = new Sprite();
public function Main()
{
sprite.graphics.beginFill(0xFF0000, 1);
sprite.graphics.drawRect(0, 0, 20, 20);
sprite.graphics.endFill();
addChild(sprite);
this.stage.addEventListener(KeyboardEvent.KEY_UP,moveSprite);
}
private function moveSprite(keyEvent:KeyboardEvent):void
{
switch (keyEvent.keyCode)
{
case 37:
sprite.x--;
break;
case 38:
sprite.y--;
break;
case 39:
sprite.x++
break;
case 40:
sprite.y++;
break;
default:
break;
}
}
}
}
</source>
Listen for the keyDown event and traces out the character code for that key.
<source lang="java">
package {
import flash.display.Sprite;
import flash.events.KeyboardEvent;
public class Main extends Sprite {
public function Main( ) {
stage.focus = this;
addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
}
private function onKeyDown(event:KeyboardEvent):void {
trace("key down: " + event.charCode);
}
}
}
</source>
Multilocation keys
<source lang="java">
package {
import flash.display.*;
import flash.events.*;
import flash.ui.*;
public class Main extends Sprite {
public static const A_KEY:int = 65;
public function Main() {
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDownListener);
}
private function keyDownListener (e:KeyboardEvent):void {
if (e.keyCode == Keyboard.SHIFT) {
if (e.keyLocation == KeyLocation.LEFT) {
trace("The left Shift key was pressed");
} else if (e.keyLocation == KeyLocation.RIGHT) {
trace("The right Shift key was pressed");
}
}
}
}
}
</source>
Reference key code with Keyboard.ESCAPE
<source lang="java">
package {
import flash.display.*;
import flash.events.*;
import flash.text.*;
import flash.ui.Keyboard;
public class Main extends Sprite {
private var keyoutput:TextField;
public function Main() {
keyoutput = new TextField( );
keyoutput.text = "Press any key...";
keyoutput.autoSize = TextFieldAutoSize.LEFT;
keyoutput.border = true;
keyoutput.background = true;
addChild(keyoutput);
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDownListener);
}
private function keyDownListener (e:KeyboardEvent):void {
if (e.keyCode == Keyboard.ESCAPE) {
trace("The Escape key was pressed");
}
}
}
}
</source>
Retrieving a pressed key"s key code through KeyboardEvent.KEY_DOWN event
<source lang="java">
package {
import flash.display.*;
import flash.events.*;
import flash.text.*;
public class Main extends Sprite {
private var keyoutput:TextField;
public function Main() {
keyoutput = new TextField();
keyoutput.text = "Press any key...";
keyoutput.autoSize = TextFieldAutoSize.LEFT;
keyoutput.border = true;
keyoutput.background = true;
addChild(keyoutput);
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDownListener);
}
private function keyDownListener (e:KeyboardEvent):void {
keyoutput.text = "The key code for the key you pressed is: " + e.keyCode;
}
}
}
</source>
Understanding keyCodes
<source lang="java">
package {
import flash.display.Sprite;
import flash.events.KeyboardEvent;
public class Main extends Sprite
{
private var sprite:Sprite = new Sprite();
public function Main()
{
sprite.graphics.beginFill(0xFF0000, 1);
sprite.graphics.drawRect(0, 0, 20, 20);
sprite.graphics.endFill();
addChild(sprite);
this.stage.addEventListener(KeyboardEvent.KEY_UP,moveSprite);
}
private function moveSprite(keyEvent:KeyboardEvent):void
{
switch (keyEvent.keyCode)
{
case 37:
sprite.x--;
break;
case 38:
sprite.y--;
break;
case 39:
sprite.x++
break;
case 40:
sprite.y++;
break;
default:
break;
}
}
}
}
</source>
Up / Left Sensor
<source lang="java">
package {
import flash.display.*;
import flash.events.*;
import flash.ui.*;
public class Main extends Sprite {
private var upPressed:Boolean;
private var leftPressed:Boolean;
public function Main ( ) {
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDownListener);
stage.addEventListener(KeyboardEvent.KEY_UP, keyUpListener);
}
private function keyDownListener (e:KeyboardEvent):void {
if (e.keyCode == Keyboard.UP) {
upPressed = true;
} else if (e.keyCode == Keyboard.LEFT) {
leftPressed = true;
}
if (upPressed && leftPressed) {
trace("Up Arrow key and Left Arrow key are both pressed");
}
}
private function keyUpListener (e:KeyboardEvent):void {
if (e.keyCode == Keyboard.UP) {
upPressed = false;
} else if (e.keyCode == Keyboard.LEFT) {
leftPressed = false;
}
}
}
}
</source>
