问fwrite()文件损坏C++

EN

// used to figure out if reading in one giant swoop has to do with corruption
int BlockSize = 0x200;
// Read the file data
unsigned char* data = new unsigned char[BlockSize];
// Create a new file
FILE* output = fopen(CStringA(outputFileName), "w+");
for (int i = 0; i < *fileSize; i += BlockSize)
{
    if (*fileSize - i > BlockSize)
    {
        ZeroMemory(data, BlockSize);
        fread(data, sizeof(unsigned char), BlockSize, file);
        // Write out the data
        fwrite(data, sizeof(unsigned char), BlockSize, output);
    }
    else
    {
        int tempSize = *fileSize - i;
        ZeroMemory(data, tempSize);
        fread(data, sizeof(unsigned char), tempSize, file);
        // Write out the data
        fwrite(data, sizeof(unsigned char), tempSize, output);
    }
}
// Close the files, we're done with them
fclose(file);
fclose(output);
delete[] data;
delete fileSize;