为什么这个image_tag不能工作？

Question

我在试着让这件事起作用。

<%= image_tag('http://img.youtube.com/vi/<%= @video_tag %>/hqdefault.jpg') %>

它只适用于链接本身，但是显示它的image_tag会导致以下错误：

错误：

Showing /Users/maine/Downloads/leap_stage_v2/leap_stage_v2/app/views/songs/show.html.erb where line #19 raised:

/Users/maine/Downloads/leap_stage_v2/leap_stage_v2/app/views/songs/show.html.erb:19: syntax error, unexpected $undefined, expecting ')'
...er.safe_append='/hqdefault.jpg\') %>
...                               ^
/Users/maine/Downloads/leap_stage_v2/leap_stage_v2/app/views/songs/show.html.erb:68: syntax error, unexpected keyword_ensure, expecting ')'
/Users/maine/Downloads/leap_stage_v2/leap_stage_v2/app/views/songs/show.html.erb:70: syntax error, unexpected keyword_end, expecting ')'
Extracted source (around line #19):


   http://img.youtube.com/vi/<%= @video_tag %>/hqdefault.jpg

   <%= image_tag('http://img.youtube.com/vi/<%= @video_tag %>/hqdefault.jpg') %>


    <div class="videos">

Answer 1

不能嵌套<%标记。假设@video_tag是一个字符串，您可以执行以下操作以实现您想要的结果：

<%= image_tag("http://img.youtube.com/vi/#{@video_tag}/hqdefault.jpg") %>