它必须是.net吗?这是一些 ruby 代码,用于读取块并再次将它们写回。在中间插入您的处理
def extract_chunk(input, output)
lenword = input.read(4)
length = lenword.unpack('N')[0]
type = input.read(4)
data = length>0 ? input.read(length) : ""
crc = input.read(4)
return nil if length<0 || !(('A'..'z')===type[0,1])
#modify data here.
output.write [data.length].pack('N')
output.write type
output.write data
output.write crc(data)
return type
end
def extract_png(input, output)
hdr = input.read(8)
raise "Not a PNG File" if hdr[0,4]!= "\211PNG"
raise "file not in binary mode" if hdr[4,4]!="\r\n\032\n"
output.write(hdr)
loop do
chunk_type = extract_chunk(input,output)
p chunk_type
break if chunk_type.nil? || chunk_type == 'IEND'
end
end