Flutter 字节操作

Flutter 字节操作

记录下字节的操作，建议在查看数据的时候，将数据转为十六进制查看，

	String str = "abcdefj";
	String res = "";
	// 转为十六进制字符串
	for( int i = 0;i< str.length; i++ ) {
		res = res + str.codeUintAt(i).toRadixString(16);
	}
	var leng = (res.length / 2).round();
	String data = "dc" + "06dc" + res;
	var hex = "";
	// 加 3 ，因为我在 data 前添加 dc06dc
	List buffer = List<dynamic>.filled(leng + 3, 0 , growable: true);
	for( int i=0;i<data.length;i++ ) {
		hex = hex + data[i];
		if((i + 1) % 2 == 0) {
			// 10 转为十进制 16转为16进制
			var item = int.parse(hex, radix: 16).toRadixString(10); 
			buffer[(i / 2).round()] = int.parse(item);
			hex = "";
		}
	}
	List buf = buffer.sublist(1);
	print(buf);

2. 十进制数组 转为 Uint8List (根据个人需求 ctrl + c)

	List<int> list = [ 00, 02, 00, 00, 02,06 ];
	int leng = list.length;
	ByteData bdata = ByteData(leng + 2);
	var id = ByteData.view(bdata.buffer, 0, 1);
	id.setUint8(0, 0x7d);
	var code = ByteData.view(bdata.buffer, leng + 1 , 1);
	code.setUint8(0, 0x7d);
	var body = ByteData.view(bdata.buffer, 1, leng);
	for( int i = 0;i< leng; i++) {
		body.setUint8(i, bytes[i]);
	}
	var buf = Uint8List.view(body.buffer);

3. 同后一字节异或

	int str = 0;
	List<int> data = [ 00, 02, 00, 00, 02,06 ];
	List<int> BCC = [0];
	for(int i = 0;i< data.length;i++) {
		BCC[0] = BCC[0] ^ data[i];
	}
	String hex = (BCC[0] & oxff).toString();
	if(hex.length == 1) {
		hex = "0" + hex;
	}
	str = int.parse(hex);
	print(str);