Question

所以，我正在学习自己的ActionScript和一本书（'带有Flash的基础AS3.0 ......）。我坚持锻炼身体我必须使用箭头键和空格键制作绘图应用程序它不起作用100％。我可以画，向上，向右，向左。甚至是对角线，只有右上角和左下角你们知道我的错误在哪里吗？我也想画左上和右下.... 到目前为止，这是我的代码：

package classes{
import flash.display.Shape;
import flash.display.Sprite;
import flash.events.KeyboardEvent;
import flash.ui.Keyboard;
import flash.events.Event;

public class KeyboardDrawing extends Sprite{
    private const PIXEL_DISTANCE_TO_DRAW:uint = 2;
    private var _canvas:Sprite;
    private var _crosshair:Shape;
    private var _xDirection:int = 0;
    private var _yDirection:int = 0;
    private var _isDrawing:Boolean = false;

    public function KeyboardDrawing(){
        _canvas=new Sprite();
        addChild(_canvas);
        _crosshair=new Shape();
        drawCrosshair();
        addChild(_crosshair);
        _canvas.graphics.lineStyle(2, 0x000000);
        stage.focus=_canvas;
        _canvas.addEventListener(KeyboardEvent.KEY_DOWN, onCanvasKeyDown);
        _canvas.addEventListener(KeyboardEvent.KEY_UP, onCanvasKeyUp);
        _canvas.addEventListener(Event.ENTER_FRAME, onCanvasEnterFrame);
    }

    private function drawCrosshair():void{
        _crosshair.graphics.lineStyle(1, 0x000000);
        _crosshair.graphics.moveTo(-5, 0);
        _crosshair.graphics.lineTo(6, 0);
        _crosshair.graphics.moveTo(0, -5);
        _crosshair.graphics.lineTo(0, 6);
    }

    private function onCanvasKeyDown(event:KeyboardEvent):void{
        switch(event.keyCode){
            case Keyboard.UP:
                _yDirection = -PIXEL_DISTANCE_TO_DRAW;
                break;
            case Keyboard.DOWN:
                _yDirection = PIXEL_DISTANCE_TO_DRAW;
                break;
            case Keyboard.LEFT:
                _xDirection = -PIXEL_DISTANCE_TO_DRAW;
                break;
            case Keyboard.RIGHT:
                _xDirection = PIXEL_DISTANCE_TO_DRAW;
                break;
            case Keyboard.SPACE:
                _isDrawing = true;
                break;
        }
    }

    private function onCanvasKeyUp(event:KeyboardEvent):void{
        switch(event.keyCode){
            case Keyboard.UP:
            case Keyboard.DOWN:
                _yDirection = 0;
                break;
            case Keyboard.LEFT:
            case Keyboard.RIGHT:
                _xDirection = 0;
                break;
            case Keyboard.SPACE:
                _isDrawing = false;
                break;
        }
    }

    private function onCanvasEnterFrame(event:Event):void{
        _crosshair.x += _xDirection;
        _crosshair.y += _yDirection;
        if (_isDrawing){
            _canvas.graphics.lineTo(_crosshair.x, _crosshair.y);
        }else{
            _canvas.graphics.moveTo(_crosshair.x, _crosshair.y);
        }
    }
  }
}

Answer 1

这是键盘和某些键组合的问题。

如果您将密钥更改为WASD，那么它可以正常工作：

private function onCanvasKeyDown(event:KeyboardEvent):void{
    switch(event.keyCode){
        case Keyboard.W:
            _yDirection = -PIXEL_DISTANCE_TO_DRAW;
            break;
        case Keyboard.S:
            _yDirection = PIXEL_DISTANCE_TO_DRAW;
            break;
        case Keyboard.A:
            _xDirection = -PIXEL_DISTANCE_TO_DRAW;
            break;
        case Keyboard.D:
            _xDirection = PIXEL_DISTANCE_TO_DRAW;
            break;
        case Keyboard.SPACE:
            _isDrawing = true;
            break;
    }
}

private function onCanvasKeyUp(event:KeyboardEvent):void{
    switch(event.keyCode){
        case Keyboard.W:
        case Keyboard.S:
            _yDirection = 0;
            break;
        case Keyboard.A:
        case Keyboard.D:
            _xDirection = 0;
            break;
        case Keyboard.SPACE:
            _isDrawing = false;
            break;
    }
}

基本上，由于有缺陷的键盘设计，以一些关键组合为代价简化了布线。

我发现这篇文章完全解释了它：http://www.microsoft.com/appliedsciences/antighostingexplained.mspx

ActionScript：为什么我不能对角画？

1 个答案: