winse (汪维)

导出、读取 excel 用哪个 gem 包比较好啊

winse — Tue, 29 Aug 2017 15:17:38 +0800

我现在用的是 SpreadSheet，但是当我读取模板文件后进行动态插入或者删除行时，没有达到像实际操作 excel 删除行的效果，而且样式也经常失效

模板：

我想在中间多加几行，代码：

current_row = 1
5.times.each do |i|
  sheet.insert_row current_row, [i + 1, 22, '', '80.19', '']
  current_row += 1
end

然而效果完全不同。。。

而且 spreadsheet 还不支持图片插入

Ruby 的类方法怎么进行动态删除

winse — Wed, 19 Apr 2017 12:21:07 +0800

我有一个 A 类

class A
  def a
    puts 'this is method a'
  end

  def self.b
    puts 'this is method b'
  end
end

我可以删除方法 a

a = A.send :remove_method, :a
A.new.methods(false)     # => []

然而我没有找到删除类方法的方式

Prawn 设置下划线属性无效，利用 canvas 进行划线也失效

winse — Fri, 06 Jan 2017 11:53:30 +0800

写导出 pdf 的时候发现设置下划线失效，于是想用画线来代替下划线，发现也没起作用，明明上次用画线都没问题 gem prawn 2.1.0

pdf = Prawn::Document.new(
  page_size: 'A4', 
  page_layout: :portrait,
  left_margin: 50, 
  right_margin: 50, 
  top_margin: 60, 
  bottom_margin: 30, 
  background: 'public/xxxx.jpg', 
  background_scale: 0.239
)
pdf.canvas do
    pdf.line_width = 0.2
    pdf.line([0, 0], [400, 400])
end
pdf.text(
  '下划线测试', 
  align: :center, 
  size: 20, 
  leading: 20,
  styles: [:underline]
)

bundle install 时报错 # 缺了东西？

winse — Sat, 24 Dec 2016 10:59:03 +0800

各种 google、bing，就是没找到解决方法，所以来求助各位了

操作系统：ubuntu 16.04 ruby 环境：2.3.3p222 [x86_64-linux] 报错信息：

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    current directory: /home/winse/.rvm/gems/ruby-2.3.3/gems/ffi-1.9.14/ext/ffi_c
/home/winse/.rvm/rubies/ruby-2.3.3/bin/ruby -r ./siteconf20161224-5954-jxwijc.rb extconf.rb
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.


/home/winse/.rvm/rubies/ruby-2.3.3/lib/ruby/2.3.0/mkmf.rb:456:in `try_do': The compiler failed to generate an executable
file. (RuntimeError)
You have to install development tools first.
    from /home/winse/.rvm/rubies/ruby-2.3.3/lib/ruby/2.3.0/mkmf.rb:541:in `try_link0'
    from /home/winse/.rvm/rubies/ruby-2.3.3/lib/ruby/2.3.0/mkmf.rb:556:in `try_link'
    from /home/winse/.rvm/rubies/ruby-2.3.3/lib/ruby/2.3.0/mkmf.rb:657:in `try_ldflags'
    from /home/winse/.rvm/rubies/ruby-2.3.3/lib/ruby/2.3.0/mkmf.rb:1813:in `pkg_config'
    from extconf.rb:15:in `<main>'

log:

"pkg-config --exists libffi"
| pkg-config --libs libffi
=> "-lffi\n"
"gcc -o conftest -I/home/winse/.rvm/rubies/ruby-2.3.3/include/ruby-2.3.0/x86_64-linux -I/home/winse/.rvm/rubies/ruby-2.3.3/include/ruby-2.3.0/ruby/backward -I/home/winse/.rvm/rubies/ruby-2.3.3/include/ruby-2.3.0 -I.     -O3 -fno-fast-math -ggdb3 -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wunused-variable -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration -Wdeprecated-declarations -Wno-packed-bitfield-compat -Wno-maybe-uninitialized  -fPIC conftest.c  -L. -L/home/winse/.rvm/rubies/ruby-2.3.3/lib -Wl,-R/home/winse/.rvm/rubies/ruby-2.3.3/lib -L. -fstack-protector -rdynamic -Wl,-export-dynamic     -Wl,-R/home/winse/.rvm/rubies/ruby-2.3.3/lib -L/home/winse/.rvm/rubies/ruby-2.3.3/lib -lruby  -lpthread -lgmp -ldl -lcrypt -lm   -lc"
checked program was:
/* begin */
1: #include "ruby.h"
2:
3: int main(int argc, char **argv)
4: {
5:   return 0;
6: }
/* end */