C# 判断两张图片是否一致的快速方法

#region 判断图片是否一致 
/// <summary> 
/// 判断图片是否一致 
/// </summary> 
/// <param name="img">图片一</param> 
/// <param name="bmp">图片二</param> 
/// <returns>是否一致</returns> 
public bool IsSameImg(Bitmap img, Bitmap bmp) 
{ 
//大小一致 
if (img.Width == bmp.Width && img.Height == bmp.Height) 
{ 
//将图片一锁定到内存 
BitmapData imgData_i = img.LockBits(new Rectangle(0, 0, img.Width, img.Height), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb); 
IntPtr ipr_i = imgData_i.Scan0; 
int length_i = imgData_i.Width * imgData_i.Height * 3; 
byte[] imgValue_i = new byte[length_i]; 
Marshal.Copy(ipr_i, imgValue_i, 0, length_i); 
img.UnlockBits(imgData_i); 
//将图片二锁定到内存 
BitmapData imgData_b = img.LockBits(new Rectangle(0, 0, img.Width, img.Height), ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb); 
IntPtr ipr_b = imgData_b.Scan0; 
int length_b = imgData_b.Width * imgData_b.Height * 3; 
byte[] imgValue_b = new byte[length_b]; 
Marshal.Copy(ipr_b, imgValue_b, 0, length_b); 
img.UnlockBits(imgData_b); 
//长度不相同 
if (length_i != length_b) 
{ 
return false; 
} 
else 
{ 
//循环判断值 
for (int i = 0; i < length_i; i++) 
{ 
//不一致 
if (imgValue_i[i] != imgValue_b[i]) 
{ 
return false; 
} 
} 
return true; 
} 
} 
else 
{ 
return false; 
} 
} 
#endregion