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Adding a column to an existing table in a Rails migration
... names in Rails are always plural (to match DB conventions). Example using one of the steps mentioned previously-
rails generate migration addEmailToUsers
rake db:migrate
Or
You can change the schema in from db/schema.rb, Add the columns you want in the SQL query.
Run this command: rake db:...
Unable to add window — token android.os.BinderProxy is not valid; is your activity running?
...s is the best way to tell if your activity is running, see this answer for one method of doing so:
Check whether activity is active
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Is there a way to programmatically scroll a scroll view to a specific edit text?
...o, and you're basically telling the UI thread, when you can, after you've done all you had to do before now, do this (scroll). You're basically putting the scroll in the queue and letting the thread do it when it can, respecting the order of things it was doing before you requested it.
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Understanding Canvas and Surface concepts
...final display in their correct Z-order. A surface typically has more than one buffer (usually two) to do double-buffered rendering: the application can be drawing its next UI state while the surface flinger is compositing the screen using the last buffer, without needing to wait for the application...
use localStorage across subdomains
... replacing cookies with localStorage on browsers that can support it (anyone but IE). The problem is site.com and www . site.com store their own separate localStorage objects. I believe www is considered a subdomain (a stupid decision if you ask me). If a user was originally on site.com and ...
ASP.NET MVC framework 4.5 CSS bundle does not work on the hosting
... .js or .css extension.
There are two fixes for this (you only need to do ONE)
A) Remove the extensions from the bundle names. (recommended) This will cause .NET to process the request and run it through the BundleModule.
B) Add this to your web.config in the system.webServer section which will c...
How to access command line parameters?
...he former iterates over Strings (that are easy to work with) but panics if one of the arguments is not valid unicode. The latter iterates over OsStrings and never panics.
Note that the first element of the iterator is the name of the program itself (this is a convention in all major OSes), so the f...
Add x and y labels to a pandas plot
..., the index x-axis label is automatically set to the Index name, if it has one. so df2.index.name = 'x label' would work too.
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理解Python的 with 语句 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...中读取数据，然后关闭文件句柄。 Without the with statement, one would write something along the lines of: 如果不用with语句，代码如下：
file = open("/tmp/foo.txt")
data = file.read()
file.close()
There are two annoying things here. First, you end up forgetting to close...
remove_if equivalent for std::map
..., while this probably works, doesn't .erase return an iterator of the next one? So it seems like the if (Some Condition) blog should be iter = aMap.erase(iter) to be the most compatible. Perhaps I'm missing something? I lack the experience some of you have.
– taxilian
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