在这里插入代码片
```public void WipeFile(string filename, int timesToWrite)
{
try
{
if (File.Exists(filename))
{
//设置文件的属性为正常,这是为了防止文件是仅仅读
File.SetAttributes(filename, FileAttributes.Normal);
//计算扇区数目
double sectors = Math.Ceiling(new FileInfo(filename).Length / 512.0);
// 创建一个相同大小的虚拟缓存
byte[] dummyBuffer = new byte[512];
// 创建一个加密随机数目生成器
System.Security.Cryptography.RNGCryptoServiceProvider rng = new System.Security.Cryptography.RNGCryptoServiceProvider();
// 打开这个文件的FileStream
FileStream inputStream = new FileStream(filename, FileMode.Open, FileAccess.Write, FileShare.ReadWrite);
for (int currentPass = 0; currentPass < timesToWrite; currentPass++)