我正在使用一些PHP和JavaScript创建一个简单的库,我正在尝试在图像之间进行淡入淡出过渡.然后我想知道使用CSS动画之间是否存在性能差异,例如:
@-webkit-keyframes fadeIn {
0% { opacity: 0; }
100% { opacity: 1; }
}
和一个jQuery淡入淡出.
我想使用fadeIn的回调,但我也可以使用带有CSS的计时器.
对于大图像,这些中的任何一个都可能更好吗？我看不出有什么不同,但想知道它是否会影响较慢的计算机.
我刚开始看看rails上的ruby并且无法运行服务器.我正在运行ruby 2.3.0和rails 4.2.5并且在我有一个新的铁路项目之后我尝试运行bin/rails server但是得到以下错误:
Warning: Running `gem pristine --all` to regenerate your installed gemspecs (and deleting then reinstalling your bundle if you use bundle --path) will improve the startup performance of Spring.
/Users/John/.rvm/gems/ruby-head/gems/json-1.8.3/lib/json/ext.rb:13:in `require': incompatible library version - /Users/John/.rvm/gems/ruby-head/gems/json-1.8.3/lib/json/ext/parser.bundle (fatal)
from /Users/John/.rvm/gems/ruby-head/gems/json-1.8.3/lib/json/ext.rb:13:in `<module:Ext>'
from /Users/John/.rvm/gems/ruby-head/gems/json-1.8.3/lib/json/ext.rb:12:in `<module:JSON>'
from /Users/John/.rvm/gems/ruby-head/gems/json-1.8.3/lib/json/ext.rb:9:in `<top (required)>'
from /Users/John/.rvm/gems/ruby-head/gems/json-1.8.3/lib/json.rb:58:in `require'
from /Users/John/.rvm/gems/ruby-head/gems/json-1.8.3/lib/json.rb:58:in `<module:JSON>'
from /Users/John/.rvm/gems/ruby-head/gems/json-1.8.3/lib/json.rb:54:in `<top (required)>'
from /Users/John/.rvm/gems/ruby-head/gems/activesupport-4.2.5/lib/active_support/core_ext/object/json.rb:2:in `require'
from /Users/John/.rvm/gems/ruby-head/gems/activesupport-4.2.5/lib/active_support/core_ext/object/json.rb:2:in `<top (required)>'
from /Users/John/.rvm/gems/ruby-head/gems/activesupport-4.2.5/lib/active_support/core_ext/object.rb:12:in `require'
from /Users/John/.rvm/gems/ruby-head/gems/activesupport-4.2.5/lib/active_support/core_ext/object.rb:12:in `<top (required)>'
from /Users/John/.rvm/gems/ruby-head/gems/railties-4.2.5/lib/rails/configuration.rb:2:in `require'
from …我在Bash中遇到了一些问题.例如:
echo *
这将打印出当前目录中的所有文件和文件夹.例如(file1 file2 folder1 folder2)
echo */
这将使用名称后面的/打印出所有文件夹.例如(folder1/folder2 /)
我怎么能只为文件选择？例如(file1 file2)
我知道这可以通过解析ls来完成,但也知道这是一个坏主意.我尝试使用扩展blobbing,但也无法使用它.
在Objective-C(Xcode)和Python(终端)中尝试并且(1/6)*(66.900009-62.852596)两次都评估为零.有谁知道这是为什么？不应该是0.26246吗？
我不确定这是不是一个愚蠢的问题.如果我-[NSFileManger moveItemAtPath:toPath:error:]从一个地方移动文件,例如/Images/image.png说/OtherImages/image.png旧目录/Images会自动删除还是仍然存在？此外,如果我想将图像重命名为图片可以在iOS中完成,或者我只需将所有内容移动到新的路径/网址？