Qt 常用数据类型转换

1、int转QString

quint8转QString

1 quint8 k = 77;
2 QString str_1;
3 str_1 = QString::number(k, 10);
4 qDebug() << str_1;      // "77"
5 QString str_2 = QString("%1").arg(k);
6 qDebug() << str_2;      // "77"

2、quint8转QByteArray

1 QByteArray all;
2 quint8 head = 0XFF;
3 all.append(head);
4 qDebug() << all;    //"\xFF"

3、quint8转QByteArray再转quint8

 1 QByteArray all;
 2 quint8 head = 65;
 3 all.append(head);
 4 qDebug() << all;    //"A" // 可以看出是ascii码的值，65对应A
 5 QByteArray temp = all.mid(0, 1);
 6 qDebug() << temp;   //"A"
 7 char* data = temp.data();
 8 qDebug() << data;   //A
 9 quint8 i = (quint8) data[0];
10 qDebug() << i;      //65

4、QByteArray转char*

1 QByteArray b("123");
2 qDebug() << b;      //"123"
3 char* d = b.data();
4 qDebug() << d;      //123

5、quint8转QByteArray（感觉QByteArray.toInt()等方法很不好用。。）

1 quint8 q = 65;
2 QByteArray b;
3 b.setNum(q, 10);
4 qDebug() << b;  //"65"
5 qDebug() << "int:" << b.toInt() << " hex:" << b.toHex();    //int: 65  hex: "3635" 
6 // int转成功了，但是hex...额，没有看懂

6、QString转char*

1 QString str("123");
2 std::string temp = str.toStdString();
3 const char* constChar = temp.c_str();
4 char* result = new char[strlen(constChar) + 1];
5 strcpy(result, constChar);
6 qDebug() << result;     //123

7、quint16转char*

1 quint16 code = 9299;
2 char buff[3];
3 memcpy(buff,&code,sizeof(quint16));
4 qDebug() << buff;   //S$

8、char*转quint16

1 // buff为上一点中的数据
2 quint16 res = *((quint16*)buff);
3 qDebug() << res; //9299

9、quint16转QByteArray再转quint16

 1 QByteArray q;
 2 quint16 code = 9299;
 3 char buff[3];
 4 memcpy(buff,&code,sizeof(quint16));//quint16转char*
 5 qDebug() << buff;   //S$
 6  
 7 q.append(buff);     //char*转为QByteArray
 8 char *temp = q.data();  // QByteArray转char*
 9 quint16 res = *((quint16*)temp);// char*转quint16
10 qDebug() << "size:" << q.length() << " byte:" << q << " res:" << res;//size: 2  byte: "S$"  res: 9299