_root.createEmptyMovieClip("terrain", 1);

　　这个函数的功能是创建一个空的MC，名字为terrain。

　　然后开始画线：

_root.terrain.lineStyle(10, 0xff0000, 100);

　　10代表线的粗细；0xff0000代表线颜色；100代表线的alpha为100。

　　你可以查看一下手册lineStyle函数的使用。

　　下面开始具体给出画线的代码：

　　画红色矩形：

createEmptyMovieClip("terrain", 1);
terrain.lineStyle(10, 0xff00ff, 100);
terrain.moveTo(100, 100);
terrain.lineTo(300, 100);
terrain.lineTo(300, 300);
terrain.lineTo(100, 300);
terrain.lineTo(100, 100);

效果：

 

鼠标画线：

createEmptyMovieClip("terrain", 1);
terrain.lineStyle(10, 0xff00ff, 100);
onEnterFrame = function () {
    terrain.lineTo(_xmouse, _ymouse);
};

效果：

 

改变帧频为50fps

 只

有按一下鼠标才能画：

createEmptyMovieClip("terrain", 1);
terrain.lineStyle(10, 0xff00ff, 100);
imdrawing = false;
onMouseDown = function () {
    if (imdrawing == false) {
        terrain.moveTo(_xmouse, _ymouse);
        imdrawing = true;
    }
    if (imdrawing == true) {
        onEnterFrame = function () {
            terrain.lineTo(_xmouse, _ymouse);
        };
    }
};
onMouseUp = function () {
    onEnterFrame = function () {
        imdrawing = false;
    };
};

效果：

 

添加一些其它的画线效果：

import flash.filters.BevelFilter;
var distance:Number = 2;
var angleInDegrees:Number = 45;
var highlightColor:Number = 0xff00ff;
var highlightAlpha:Number = 1;
var shadowColor:Number = 0xbb00bb;
var shadowAlpha:Number = 1;
var blurX:Number = 8;
var blurY:Number = 8;
var strength:Number = 10;
var quality:Number = 3;
var type:String = "inner";
var knockout:Boolean = false;
var my_bevel_filter:BevelFilter = new BevelFilter(distance, angleInDegrees, highlightColor, highlightAlpha, shadowColor, shadowAlpha, blurX, blurY, strength, quality, type, knockout);
createEmptyMovieClip("terrain", 1);
terrain.lineStyle(20, 0xdd00dd, 100);
terrain.filters = new Array(my_bevel_filter);
imdrawing = false;
onMouseDown = function () {
    if (imdrawing == false) {
        terrain.moveTo(_xmouse, _ymouse);
        imdrawing = true;
    }
    if (imdrawing == true) {
        onEnterFrame = function () {
            terrain.lineTo(_xmouse, _ymouse);
        };
    }
};
onMouseUp = function () {
    onEnterFrame = function () {
        imdrawing = false;
    };
};

效果：

 

模糊效果画线：

import flash.filters.BlurFilter;
var blurX:Number = 30;
var blurY:Number = 30;
var quality:Number = 3;
var my_blur_filter:BlurFilter = new BlurFilter(blurX, blurY, quality);
createEmptyMovieClip("terrain", 1);
terrain.lineStyle(20, 0xdd00dd, 100);
terrain.filters = new Array(my_blur_filter);
imdrawing = false;
onMouseDown = function () {
    if (imdrawing == false) {
        terrain.moveTo(_xmouse, _ymouse);
        imdrawing = true;
    }
    if (imdrawing == true) {
        onEnterFrame = function () {
            terrain.lineTo(_xmouse, _ymouse);
        };
    }
};
onMouseUp = function () {
    onEnterFrame = function () {
        imdrawing = false;
    };
};

效果：

 

发光效果画线代码：

import flash.filters.GlowFilter;
var color:Number = 0x33CCFF;
var alpha:Number = .8;
var blurX:Number = 35;
var blurY:Number = 35;
var strength:Number = 2;
var quality:Number = 3;
var inner:Boolean = false;
var knockout:Boolean = false;
var my_glow_filter:GlowFilter = new GlowFilter(color, alpha, blurX, blurY, strength, quality, inner, knockout);
createEmptyMovieClip("terrain", 1);
terrain.lineStyle(20, 0xdd00dd, 100);
terrain.filters = new Array(my_glow_filter);
imdrawing = false;
onMouseDown = function () {
    if (imdrawing == false) {
        terrain.moveTo(_xmouse, _ymouse);
        imdrawing = true;
    }
    if (imdrawing == true) {
        onEnterFrame = function () {
            terrain.lineTo(_xmouse, _ymouse);
        };
    }
};
onMouseUp = function () {
    onEnterFrame = function () {
        imdrawing = false;
    };
};

效果：

 

画阴影线的代码：

import flash.filters.DropShadowFilter;
var distance:Number = 20;
var angleInDegrees:Number = 45;
var color:Number = 0x000000;
var alpha:Number = .8;
var blurX:Number = 16;
var blurY:Number = 16;
var strength:Number = 1;
var quality:Number = 3;
var inner:Boolean = false;
var knockout:Boolean = false;
var hideObject:Boolean = false;
var my_shadow_filter:DropShadowFilter = new DropShadowFilter(distance, angleInDegrees, color, alpha, blurX, blurY, strength, quality, inner, knockout, hideObject);
createEmptyMovieClip("terrain", 1);
terrain.lineStyle(20, 0xdd00dd, 100);
terrain.filters = new Array(my_shadow_filter);
imdrawing = false;
onMouseDown = function () {
    if (imdrawing == false) {
        terrain.moveTo(_xmouse, _ymouse);
        imdrawing = true;
    }
    if (imdrawing == true) {
        onEnterFrame = function () {
            terrain.lineTo(_xmouse, _ymouse);
        };
    }
};
onMouseUp = function () {
    onEnterFrame = function () {
        imdrawing = false;
    };
};

效果：

 

上面所有效果都混合在一起：

// bevel filter
import flash.filters.BevelFilter;
var distance:Number = 5;
var angleInDegrees:Number = 45;
var highlightColor:Number = 0xFFFF00;
var highlightAlpha:Number = .8;
var shadowColor:Number = 0x0000FF;
var shadowAlpha:Number = .8;
var blurX:Number = 5;
var blurY:Number = 5;
var strength:Number = 5;
var quality:Number = 3;
var type:String = "inner";
var knockout:Boolean = false;
var my_bevel_filter:BevelFilter = new BevelFilter(distance, angleInDegrees, highlightColor, highlightAlpha, shadowColor, shadowAlpha, blurX, blurY, strength, quality, type, knockout);
// blur filter
import flash.filters.BlurFilter;
var blurX:Number = 30;
var blurY:Number = 30;
var quality:Number = 3;
var my_blur_filter:BlurFilter = new BlurFilter(blurX, blurY, quality);
// shadow
import flash.filters.DropShadowFilter;
var distance:Number = 20;
var angleInDegrees:Number = 45;
var color:Number = 0x000000;
var alpha:Number = .8;
var blurX:Number = 16;
var blurY:Number = 16;
var strength:Number = 1;
var quality:Number = 3;
var inner:Boolean = false;
var knockout:Boolean = false;
var hideObject:Boolean = false;
var my_shadow_filter:DropShadowFilter = new DropShadowFilter(distance, angleInDegrees, color, alpha, blurX, blurY, strength, quality, inner, knockout, hideObject);
// glow
import flash.filters.GlowFilter;
var color:Number = 0x33CCFF;
var alpha:Number = .8;
var blurX:Number = 35;
var blurY:Number = 35;
var strength:Number = 2;
var quality:Number = 3;
var inner:Boolean = false;
var knockout:Boolean = false;
var my_glow_filter:GlowFilter = new GlowFilter(color, alpha, blurX, blurY, strength, quality, inner, knockout);
_root.createEmptyMovieClip("terrain", 1);
_root.terrain.lineStyle(10, 0xff00ff, 100);createEmptyMovieClip("terrain", 1);
terrain.lineStyle(20, 0xdd00dd, 100);
terrain.filters = new Array(my_shadow_filter,my_glow_filter,my_blur_filter,my_bevel_filter);
imdrawing = false;
onMouseDown = function () {
    if (imdrawing == false) {
        terrain.moveTo(_xmouse, _ymouse);
        imdrawing = true;
    }
    if (imdrawing == true) {
        onEnterFrame = function () {
            terrain.lineTo(_xmouse, _ymouse);
        };
    }
};
onMouseUp = function () {
    onEnterFrame = function () {
        imdrawing = false;
    };
};

效果：