| 本文中我们用Flash的AS代码来写一段实例，模仿设计软件中贝塞尔曲线的控制。
下面是完成效果：
用鼠标点击拖动灰色的方形锚点，即可看见曲线的变化（小心不要拖出画面了）
AS代码如下：
//这个函数是用来绘制线条的
function connect(){
this.clear()
this.lineStyle(3,0x660000,100)
this.moveTo(anchorOne._x,anchorOne._y)
this.curveTo(controlOne._x,controlOne._y,anchorTwo._x,anchorTwo._y)
updateAfterEvent()
}
//这个函数是用来绘制替代描点跟控制点的MC，就绘制一个正方形吧
function createSquare(handle,side,offset){
if(offset==undefines){
offset=0
}
with(handle){
moveTo(offset,offset)
lineTo(offset,side)
lineTo(side,side)
lineTo(side,offset)
lineTo(offset,offset)
endFill()
}
}
//这是用来控制描点跟控制点的移动，并且用延时，间隔一段时间调用一次绘制线条
function setDraggable(handle){
handle.onPress=function(){
clearInterval(_global.refreshScreen)
_global.refreshScreen=setInterval(this._parent,"connect",10)
this.startDrag(false)
}
handle.onRelease=function(){
clearInterval(_global.refreshScreen)
this.stopDrag()
}
handle.onReleaseOutside=function(){
clearInterval(_global.refreshScreen)
this.stopDrag()
}
}
//建立描点
anchorOne=createEmptyMovieClip("anchorPoint1",this.getNextHighestDepth())
anchorOne._x=anchorOne._y=50
//填充
anchorOne.beginFill(0xcccccc,100)
//样式
anchorOne.lineStyle(0,0x000000,100,false,false,"none","miter",2)
//调用函数绘制成正方形
createSquare(anchorOne,8,-8)
//调用后方可拖动
setDraggable(anchorOne)
//另一个描点
anchorTwo=createEmptyMovieClip("anchorPoint2",this.getNextHighestDepth())
anchorTwo._x=anchorTwo._y=250
anchorTwo.beginFill(0xcccccc,100)
anchorTwo.lineStyle(0,0x000000,100,false,false,"none","miter",2)
createSquare(anchorTwo,8,-8)
setDraggable(anchorTwo)
//控制点
controlOne=createEmptyMovieClip("control1",this.getNextHighestDepth())
controlOne._x=anchorTwo._x
controlOne._y=anchorOne._y
controlOne.beginFill(0xcccccc,100)
controlOne.lineStyle(0,0x000000,100,false,false,"none","miter",2)
createSquare(controlOne,8,-8)
setDraggable(controlOne)
//最后让线条一开始就显示出来
connect() |
复制粘贴到到吗层，测试即可看到效果。
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