处理二进制

Uint8List data;


#偏移截取
ByteData headerData = ByteData.sublistView(data, 0, 12);


var header = headerData.buffer.asUint8List();

// 创建一个从输入二进制数据的 
io.Readervar dataBuff = ByteData.view(header.buffer);

//从0开始读取四个字节
var msgid = dataBuff.getUint32(0, Endian.little)
//从4开始读取四个字节
var len = dataBuff.getUint32(4, Endian.little)

//转为utf8 文字
const decoder = Utf8Decoder();  
var result = decoder.convert(  
    data, 12 , 12 + len);  
Logger.log(result);


//utf8 文字 转 Uint8List
String str = "Hello, world!"; 
Uint8List uint8List = utf8.encode(str); 

print(uint8List);

//使用字节偏移量（0、4、8）来设置每个字符的值  Uint32  需要4个字节
//使用字节偏移量（0、2、4）来设置每个字符的值，因为Int16需要2个字节
//Uint8 需要一个字节


static Uint8List packMsg(Msg msg) {

// 创建一个存放 bytes 字节的缓冲

var dataBuff = ByteData(0);

  

// 写 msgID

dataBuff.setUint32(0, msg.getMsgId(), Endian.little);

  

// 写 headerLen

dataBuff.setUint32(4, msg.getHeaderLen(), Endian.little);

  

// 写 bodyLen

dataBuff.setUint32(8, msg.getBodyLen(), Endian.little);

  

// 写 header

var header = msg.getHeader();

for (var i = 0; i < header.length; i++) {

dataBuff.setUint8(8 + i, header[i]);

}

  

// 写 data 数据

var body = msg.getBody();

for (var i = 0; i < body.length; i++) {

dataBuff.setUint8(8 + header.length + i, body[i]);

}

  

return dataBuff.buffer.asUint8List();

}

List<int>   Uint8List 互转

List<int> intList = [1, 2, 3];
Uint8List uint8List = Uint8List.fromList(intList);
print(uint8List); // 输出: [1, 2, 3]

// 将Uint8List转换为List<int>
Uint8List uint8List2 = Uint8List.fromList([4, 5, 6]);
List<int> intList2 = uint8List2.toList();