大约有 32,000 项符合查询结果（耗时：0.0425秒） [XML]
catch exception that is thrown in different thread
...n an exception is thrown.
I need to get that exception information on the calling method ( Method1 )
4 Answers
...
Is there a performance difference between i++ and ++i in C?
...
Executive summary: No.
i++ could potentially be slower than ++i, since the old value of i
might need to be saved for later use, but in practice all modern
compilers will optimize this away.
We can demonstrate this by looking at the code for this function,
both wit...
What's the point of having pointers in Go?
I know that pointers in Go allow mutation of a function's arguments, but wouldn't it have been simpler if they adopted just references (with appropriate const or mutable qualifiers). Now we have pointers and for some built-in types like maps and channels implicit pass by reference.
...
rails - Devise - Handling - devise_error_messages
...hould help you get started. :)
Another update
The resource object is actually the model that is being used by devise (go figure).
resource.class #=> User
resource.errors.class #=> ActiveModel::Error
It also appears to be defined in a higher scope (probably coming from the contro...
mongoDB/mongoose: unique if not null
...ngoDB v1.8+ you can get the desired behavior of ensuring unique values but allowing multiple docs without the field by setting the sparse option to true when defining the index. As in:
email : {type: String, trim: true, index: true, unique: true, sparse: true}
Or in the shell:
db.users.ensureIn...
Add Bootstrap Glyphicon to Input Box
...in Plunker
Note: This presumes you're using glyphicons, but works equally well with font-awesome.
For FA, just replace .glyphicon with .fa
With Bootstrap:
As buffer points out, this can be accomplished natively within Bootstrap by using Validation States with Optional Icons. This is do...
What is a Manifest in Scala and when do you need it?
Since Scala 2.7.2 there is something called Manifest which is a workaround for Java's type erasure. But how does Manifest work exactly and why / when do you need to use it?
...
How to create a density plot in matplotlib?
...with R. This is because gaussian_kde tries to infer the bandwidth automatically. You can play with the bandwidth in a way by changing the function covariance_factor of the gaussian_kde class. First, here is what you get without changing that function:
However, if I use the following code:
import...
What is the difference between Pan and Swipe in iOS?
...esture is continuous. It begins (began) when the minimum number of fingers allowed (minimumNumberOfTouches) has moved enough to be considered a pan. It changes (changed) when a finger moves while at least the minimum number of fingers are pressed down. It ends (ended) when all fingers are lifted.
C...
Android static object lifecycle
...cation?
The OS starts a process and assigns it a unique process id and allocates a process table.A process start an instance of DVM(Dalvik VM); Each application runs inside a DVM.
A DVM manages class loading unloading, instance lifecycle, GC etc.
Lifetime of a static variable: A static variable...