//将vec里的内容写出到文件
fn write_vec_to_file(slice: Vec<String>, filename: &str) -> std::io::Result<()> {
    let new_content = slice.join("\r\n");
    std::fs::write(filename, new_content)?;
    // println!("{:#?}",new_content);
    // println!("保存文件:{}",filename);
    Ok(())
} // fn end