QString::number(data/100.0,'f',2)
时间: 2024-02-25 07:52:30 浏览: 149
`QString::number(data/100.0,'f',2)`将数值格式化为小数形式,并保留两位小数。例如,如果`data`是300,那么这个表达式将会返回一个字符串"3.00"。如果你需要更高的精度,你可以增加保留的小数位数,例如:
```cpp
QString str = QString::number(data/100.0, 'f', 6);
```
这将保留六位小数,例如如果`data`是300,那么这个表达式将会返回一个字符串"3.000000"。
相关问题
QString::number(data/100.0,'f',2)精度不够
如果你想要更高的精度,你可以尝试使用QString::setNum()函数,并将它的第二个参数设置为'g',如下所示:
```cpp
QString str = QString::number(data/100.0, 'g', 16);
```
这将使用科学计数法来表示数字,并且保留16位有效数字,从而提高精度。你也可以根据需要调整有效数字的位数。
// 若对方发送方式是字节流,则会进入此函数 void mqMsgHandleByte(const char* data, int size) { //监听飞仿发送的遥测数据包 if (size == sizeof(struct FlySARCtrlStatus)) { MqMessage::getMqMessageInstance().setFlyCtrStatus(*(FlySARCtrlStatus*)data); } void MqMessage::setFlyCtrStatus(FlySARCtrlStatus flyControlStatus) { this->flyControlStatus = flyControlStatus; } FlySARCtrlStatus MqMessage::getFlyCtrStatus() { return this->flyControlStatus; } QTime time; QTimer* tim; tim = new QTimer(this); tim->setInterval(100); tim->start(); connect(tim, SIGNAL(timeout()), this, SLOT(ChangeStateFly())); void load_radar::ChangeStateFly() { //QString::number(str_fly.flyheight)将 str_fly.flyheight 转换为字符串类型 //获取到飞行状态信息 //结构体类型对象 FlySARCtrlStatus str_fly = MqMessage::getFlyMqMessage().getFlyCtrStatus(); ui.labShowPlaneSpeed->setText(QString::number(str_fly.groundspeed) + "Km/h"); }有问题请修改
根据之前提到的问题,可以对代码进行如下修改:
1. mqMsgHandleByte函数中添加数据有效性检查。
```
void mqMsgHandleByte(const char* data, int size)
{
// 监听飞仿发送的遥测数据包
if (size == sizeof(struct FlySARCtrlStatus))
{
FlySARCtrlStatus flyControlStatus = *(FlySARCtrlStatus*)data;
// 添加数据有效性检查
if (isValid(flyControlStatus))
{
MqMessage::getMqMessageInstance().setFlyCtrStatus(flyControlStatus);
}
}
}
bool isValid(const FlySARCtrlStatus& flyControlStatus)
{
// 添加数据有效性检查
if (flyControlStatus.groundspeed < 0 || flyControlStatus.flyheight < 0)
{
return false;
}
return true;
}
```
2. setFlyCtrStatus函数中添加参数有效性检查。
```
void MqMessage::setFlyCtrStatus(const FlySARCtrlStatus& flyControlStatus)
{
// 添加参数有效性检查
if (isValid(flyControlStatus))
{
this->flyControlStatus = flyControlStatus;
}
}
bool isValid(const FlySARCtrlStatus& flyControlStatus)
{
// 添加数据有效性检查
if (flyControlStatus.groundspeed < 0 || flyControlStatus.flyheight < 0)
{
return false;
}
return true;
}
```
3. getFlyCtrStatus函数中添加成员变量有效性检查。
```
FlySARCtrlStatus MqMessage::getFlyCtrStatus()
{
// 添加成员变量有效性检查
if (isValid(this->flyControlStatus))
{
return this->flyControlStatus;
}
return FlySARCtrlStatus();
}
bool isValid(const FlySARCtrlStatus& flyControlStatus)
{
// 添加数据有效性检查
if (flyControlStatus.groundspeed < 0 || flyControlStatus.flyheight < 0)
{
return false;
}
return true;
}
```
4. ChangeStateFly函数中添加获取飞行状态信息的有效性检查和QString::number函数返回值的有效性检查。
```
void load_radar::ChangeStateFly()
{
FlySARCtrlStatus flyControlStatus = MqMessage::getFlyMqMessage().getFlyCtrStatus();
// 添加获取飞行状态信息的有效性检查
if (isValid(flyControlStatus))
{
QString groundspeedStr = QString::number(flyControlStatus.groundspeed);
// 添加QString::number函数返回值的有效性检查
if (!groundspeedStr.isEmpty())
{
ui.labShowPlaneSpeed->setText(groundspeedStr + "Km/h");
}
}
}
```
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<html><head><meta http-equiv="Content-Type" content="text/html; charset=
=iso-8859-1">
<title>Trioptics Certificate</title>
<base href="file:///C:/Program%20Files%20(x86)/TRIOPTICS%20GmbH/MTF-LAB%2=
05/Certificates/"></base></head>
<body id="IBodyCert" class="CBodyCert">
ImageMaster - Certificate
Company : ******
Operator : ******
Time/Date : 13:30:33 June 12, 2025
Sample ID : ******
Measure Program : MTF vs. Field
Temperature : 20°C
Measured with : TRIOPTICS - MT=
F-LAB - Vers. 5.16.1
Instrument S/N : 09-113-0519
Comments : SN215U0540
Measurement Parameter: MTF vs. Image Height
Setup Type : Object Infinite / Image Finite
EFL (Collimator): 50 mm
Wavelength : 940 nm (NIR)
EFL (Sample) : 1.5550 mm
F-Number : 2.0000
Object Angle : -0.0198 °
Focus Position : 85.8471
Sample Azimuth : 0.0 °
Measurement Graph: MTF vs. Image Height
<right>
</right>
Measurement Table: MTF vs. Image Height
Image Height (mm)
MTF
0.42800
0.29960
-0.00114
-0.29960
-0.42800
Legend
Tan 100(lp/mm)
0.599
0.677
0.668
0.703
0.645
— — —
Sag 100(lp/mm)
0.558
0.659
0.673
0.688
0.642
————
Measurement Parameter: MTF vs. Object Angle
Setup Type : Object Infinite / Image Finite
EFL (Collimator): 50 mm
Wavelength : 940 nm (NIR)
EFL (Sample) : 1.5550 mm
F-Number : 2.0000
Object Angle : -0.0198 °
Focus Position : 85.8471
Sample Azimuth : 0.0 °
Measurement Graph: MTF vs. Object Angle
<right>
</right>
Measurement Table: MTF vs. Object Angle
Object Angle (?
MTF
-15.33590
-10.72937
0.00072
10.77662
15.40352
Legend
Tan 100(lp/mm)
0.599
0.677
0.668
0.703
0.645
— — —
Sag 100(lp/mm)
0.558
0.659
0.673
0.688
0.642
————
</body></html> 解析这个

Measurement Parameter: MTF vs. Image Height Setup Type : Object Infinite / Image Finite EFL (Collimator): 50 mm Wavelength : 940 nm (NIR) EFL (Sample) : 1.5550 mm F-Number : 2.0000 Object Angle : -0.0198 ° Focus Position : 85.8471 Sample Azimuth : 0.0 °
Measurement Graph: MTF vs. Image Height
<right>
Measurement Table: MTF vs. Image Height
Measurement Parameter: MTF vs. Object Angle Setup Type : Object Infinite / Image Finite EFL (Collimator): 50 mm Wavelength : 940 nm (NIR) EFL (Sample) : 1.5550 mm F-Number : 2.0000 Object Angle : -0.0198 ° Focus Position : 85.8471 Sample Azimuth : 0.0 °
Measurement Graph: MTF vs. Object Angle
<right>
Measurement Table: MTF vs. Object Angle
