从另一个类别调用函数时出现错误:字段初始值设定项无法引用非静态字段,方法或属性
问题描述:
我在调用类的类USBDriveSerialNumber
的公共方法getSerialNumberFromDriveLetter
时出现此错误。从另一个类别调用函数时出现错误:字段初始值设定项无法引用非静态字段,方法或属性
错误:字段初始值设定项无法引用非静态字段,方法或属性。
我的代码
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
namespace WindowsFormsApplication2
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
USBDriveSerialNumber usb = new USBDriveSerialNumber();
string serial = usb.getSerialNumberFromDriveLetter("f:\\");
// Debug.WriteLine(serial);
}
}
//USBDriveSerialNumber Class
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Management;
namespace WindowsFormsApplication2
{
class USBDriveSerialNumber
{
string _serialNumber;
string _driveLetter;
public string getSerialNumberFromDriveLetter(string driveLetter)
{
this._driveLetter = driveLetter.ToUpper();
if (!this._driveLetter.Contains(":"))
{
this._driveLetter += ":";
}
matchDriveLetterWithSerial();
return this._serialNumber;
}
public void matchDriveLetterWithSerial()
{
string[] diskArray;
string driveNumber;
string driveLetter;
ManagementObjectSearcher searcher1 = new ManagementObjectSearcher("SELECT * FROM Win32_LogicalDiskToPartition");
foreach (ManagementObject dm in searcher1.Get())
{
diskArray = null;
driveLetter = getValueInQuotes(dm["Dependent"].ToString());
diskArray = getValueInQuotes(dm["Antecedent"].ToString()).Split(',');
driveNumber = diskArray[0].Remove(0, 6).Trim();
if (driveLetter == this._driveLetter)
{
/* This is where we get the drive serial */
ManagementObjectSearcher disks = new ManagementObjectSearcher("SELECT * FROM Win32_DiskDrive");
foreach (ManagementObject disk in disks.Get())
{
if (disk["Name"].ToString() == ("\\\\.\\PHYSICALDRIVE" + driveNumber) & disk["InterfaceType"].ToString() == "USB")
{
this._serialNumber = parseSerialFromDeviceID(disk["PNPDeviceID"].ToString());
}
}
}
}
}
private string parseSerialFromDeviceID(string deviceId)
{
string[] splitDeviceId = deviceId.Split('\\');
string[] serialArray;
string serial;
int arrayLen = splitDeviceId.Length - 1;
serialArray = splitDeviceId[arrayLen].Split('&');
serial = serialArray[0];
return serial;
}
private string getValueInQuotes(string inValue)
{
string parsedValue = "";
int posFoundStart = 0;
int posFoundEnd = 0;
posFoundStart = inValue.IndexOf("\"");
posFoundEnd = inValue.IndexOf("\"", posFoundStart + 1);
parsedValue = inValue.Substring(posFoundStart + 1, (posFoundEnd - posFoundStart) - 1);
return parsedValue;
}
}
}
答
你应该叫getSerialNumberFromDriveLetter方法内部构造或创建一个新的方法
public Form1()
{
InitializeComponent();
USBDriveSerialNumber usb = new USBDriveSerialNumber();
string serial = usb.getSerialNumberFromDriveLetter("f:\\");
}
答
不能使用实例变量初始化另一个实例变量,因为编译器重新排列这些变量。
将其更改为
string serial = new USBDriveSerialNumber().getSerialNumberFromDriveLetter("f:\\");
或使USB静态
static USBDriveSerialNumber usb = new USBDriveSerialNumber();
string serial = usb.getSerialNumberFromDriveLetter("f:\\");
或移动设置串行构造器
string serial;
public Form1()
{
InitializeComponent();
serial = usb.getSerialNumberFromDriveLetter("f:\\");
}
三江源的解决方案,现在它工作正常 –