我从GitHub存储库中克隆了一个app文件夹,在bundle安装gems后,我尝试使用rake db:reset和rake db:migrate命令,两者都没有工作,这是我的错误信息:
>[app_folder]rake db:reset
rake aborted!
Could not load database configuration. No such file - /Users/harry/Dropbox/apps/app_folder/config/database.yml
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/application/configuration.rb:110:in `database_configuration'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/railtie.rb:174:in `block (2 levels) in <class:Railtie>'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:38:in `instance_eval'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:38:in `execute_hook'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:28:in `block in on_load'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:27:in `each'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/lazy_load_hooks.rb:27:in `on_load'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activerecord-4.0.0/lib/active_record/railtie.rb:173:in `block in <class:Railtie>'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `instance_exec'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `run'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/initializable.rb:55:in `block in run_initializers'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/initializable.rb:54:in `run_initializers'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/application.rb:215:in `initialize!'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
/Users/harry/Dropbox/apps/app_folder/config/environment.rb:5:in `<top (required)>'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `block in require'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:213:in `load_dependency'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/application.rb:189:in `require_environment!'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/gems/railties-4.0.0/lib/rails/application.rb:249:in `block in run_tasks_blocks'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/bin/ruby_executable_hooks:15:in `eval'
/usr/local/rvm/gems/ruby-2.0.0-p353@railstutorial_rails_4_0/bin/ruby_executable_hooks:15:in `<main>'
Tasks: TOP …我需要实现一个for从一个浮点数到另一个浮点数的循环,其中步长为另一个浮点数.
我知道如何用类C语言实现它:
for (float i = -1.0; i < 1.0; i += 0.01) { /* ... */ }
我也知道在Rust中我可以使用指定循环步骤step_by,如果我有边界值并且步长为整数,那么它给了我想要的东西:
#![feature(iterator_step_by)]
fn main() {
for i in (0..30).step_by(3) {
println!("Index {}", i);
}
}
当我使用浮点数时,它会导致编译错误:
#![feature(iterator_step_by)]
fn main() {
for i in (-1.0..1.0).step_by(0.01) {
println!("Index {}", i);
}
}
这是编译输出:
error[E0599]: no method named `step_by` found for type `std::ops::Range<{float}>` in the current scope
--> src/main.rs:4:26
|
4 | for i in (-1.0..1.0).step_by(0.01) {
| ^^^^^^^
|
= …我正在写一个Vala应用程序,我在其中使用标签.这是构造函数(我想这是导致错误的地方):
titleLabel = new Gtk.Label("");
titleLabel.set_markup(wrapInTags(post.title));
titleLabel.set_line_wrap(true);
titleLabel.wrap_mode = Pango.WrapMode.WORD_CHAR;
titleLabel.set_justify(Gtk.Justification.LEFT);
//titleLabel.set_max_width_chars(40);
titleLabel.set_xalign(0);
当我编译它时,会发生这种情况:
CMakeFiles/photostream.dir/Widgets/PostBox.c.o: In function `photo_stream_widgets_post_box_construct':
PostBox.c:(.text+0x2111): undefined reference to `gtk_label_set_xalign'
CMakeFiles/photostream.dir/Widgets/CommentsBox.c.o: In function `photo_stream_widgets_comment_box_construct':
CommentsBox.c:(.text+0x1045): undefined reference to `gtk_label_set_xalign'
CMakeFiles/photostream.dir/Widgets/NewsBox.c.o: In function `photo_stream_widgets_news_box_construct':
NewsBox.c:(.text+0x1af8): undefined reference to `gtk_label_set_xalign'
CMakeFiles/photostream.dir/Windows/BulkDownloadWindow.c.o: In function `photo_stream_bulk_download_window_construct':
BulkDownloadWindow.c:(.text+0x14b1): undefined reference to `gtk_label_set_xalign'
collect2: error: ld returned 1 exit status
我试图替换最后一个字符串titleLabel.xalign = 0,但结果仍然相同.
我该如何解决？
我读过一些建议nginx在 Node.js 应用程序之前使用反向代理的文章（例如 ）（例如：Advantages of a reverse proxy in front of Node.JS）。这比运行 Node.js 本身并公开它更好（至少在安全性方面）。
但是，在 Docker 容器内运行 Node.JS 应用程序应该可以防止安全问题（因为应用程序在容器内运行并且与主机系统隔离）。
所以，我的问题是：在 Docker 容器中运行 Node.js 应用程序时使用反向代理有好处吗？如果是这样，它如何改进我的申请？
我正在 WPF 中编写一个程序。我正在使用 HelixToolkit 从文件加载模型（我需要从文件加载多个模型），如下所示：
var importer = new HelixToolkit.Wpf.ModelImporter();
Model3D triangle = importer.Load("hand.obj");
ModelVisual3D Model = new ModelVisual3D();
Model.Content = triangle;
MainViewPort.Children.Add(Model);
我需要从 HelixToolkit 获取的整个 Model3D 来更改颜色（例如，它应该是红色或黑色）。我还需要实时进行。
我发现了这个：http://csharphelper.com/blog/2014/10/apply-textures-to-triangles-using-wpf-and-c/，但在这种情况下模型是在程序内部生成的，而我需要什么要做的就是对外部文件的模型执行相同的操作。
我怎样才能做到这一点？