PSD解析工具实现（六）

接着解析图层的adjustmentData部分信息：

第一个signature是固定的8BIM

第二个是标示下面的data内容所属类型的key

第三个是内容长度。

1var ba:ByteArray = new ByteArray();
2var signature:String = adjustmentData.readUTFBytes(4); //always 8BIM
3if("" == signature)
4{
5  throw new Error("解析文件错误了");
6  return;
7}
8var key:String = adjustmentData.readUTFBytes(4);

key值有很多种，这里只用了标示文本内容的TySh跟图层类型的lsct来举例。

1switch(key)
2{
3case "TySh": //文本内容
4{  len = adjustmentData.readUnsignedInt();
5
6adjustmentData.readBytes(ba, 0, len);
7	var version:int = ba.readShort();
8	ba.position += 48;//跳过
9	var ver1:int = ba.readShort();
10	var ver2:int = ba.readInt();
11	//descriptor
12	len = ba.readInt()*2; //the string of unicode values, two bytes per character
13	ba.position += len;
14	len = ba.readInt();
15	if(0 == len)
16	{
17		ba.position += 4;
18	} 
19
20var numOfItems:int = ba.readInt();
21	var descripterKey:String;
22	var typeTxt:String;
23	for (var i:int = 0; i < numOfItems; i++) 
24	{ 
25		descripterKey = ba.readUTFBytes(4);
26		if("" == descripterKey)
27		{
28			descripterKey = ba.readUTFBytes(4);
29		}
30		typeTxt = ba.readUTFBytes(4);
31		switch(descripterKey) 
32		{
33			case 'Txt ':
34			   textContent = parseUnicodeString(ba);
35                           labelSheetVo = PsdUtil.psdVo.labelSheetDict[layerName];
36                           isText = true;
37                           break;
38		}
39	}
40	break;
41	}
42	case "lsct": //文件夹判断
43	{
44		len = adjustmentData.readUnsignedInt();
45		adjustmentData.readBytes(ba, 0, len);
46		//0 = any other type of layer, 1 = open “folder”, 2 = closed “folder”, 3 = bounding section divider, hidden in the UI
47		var type:int = ba.readUnsignedInt();
48		_isFolder = (1 == type || 2 == type);	
49		break;
50	}
51
52        //这几个在长度上有特殊的去读要求			
53	case "lrFX": //Effects Layer info
54	case "lfx2": //Object Based Effects Layer info 
55	case "Patt": //Patterns ase "Anno": //Annotations
56	{
57		len = adjustmentData.readUnsignedInt();
58		mode = len%4;
59		if(0 != mode)
60		{
61			adjustmentData.readBytes(ba, 0, len + 4 - mode);
62		}
63		else
64		{
65			adjustmentData.readBytes(ba, 0, len);
66		}
67		break;
68	}
69	default:
70	{
71		len = adjustmentData.readUnsignedInt();
72		adjustmentData.readBytes(ba, 0, len);
73		break;
74	}
75}