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Why is UICollectionViewCell's outlet nil?
...orrect (correct identifier & class) it refused to connect the outlets. now it works. sweet!
– Joris Weimar
Oct 9 '14 at 19:36
13
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How do you delete an ActiveRecord object?
...out a primary key
Note: from @hammady's comment, user.destroy won't work if User model has no primary key.
Note 2: From @pavel-chuchuva's comment, destroy_all with conditions and delete_all with conditions has been deprecated in Rails 5.1 - see guides.rubyonrails.org/5_1_release_notes.html
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Add & delete view from Layout
...this);
lp.addView(new Button(this));
lp.addView(new ImageButton(this));
// Now remove them
lp.removeViewAt(0); // and so on
If you have xml layout then no need to add dynamically.just call
lp.removeViewAt(0);
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Python memory usage of numpy arrays
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I use this code to get a listing of all of them and their size.
Not sure if locals() or globals() is better here.
import sys
import numpy
from humanize import naturalsize
for size, name in sorted(
(value.nbytes, name)
for name, value in locals().items()
if isinstance(value, numpy.n...
BLE协议—广播和扫描 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...广播方式的报文有4种，分别为可连接的非定向广播（ADV_IND）、可连接的定向广播（ADV_DIRECT_IND）、可扫描非定向广播（ADV_SCAN_IND）、不可连接的非定向广播（ADV_NONCONN_IND）
4种广播的使用场景各不相同
可连接的非定向广播（A...
What are some compelling use cases for dependent method types?
...pendent method types, which used to be an experimental feature before, has now been enabled by default in the trunk , and apparently this seems to have created some excitement in the Scala community.
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“java.lang.OutOfMemoryError: PermGen space” in Maven build [duplicate]
...Windows:)
set MAVEN_OPTS=-Xmx512m -XX:MaxPermSize=128m
You can also specify these JVM options in each maven project separately.
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Truncating floats in Python
...float f to n decimal places without rounding'''
s = '{}'.format(f)
if 'e' in s or 'E' in s:
return '{0:.{1}f}'.format(f, n)
i, p, d = s.partition('.')
return '.'.join([i, (d+'0'*n)[:n]])
This is valid in Python 2.7 and 3.1+. For older versions, it's not possible to get the ...
Asp.NET Web API - 405 - HTTP verb used to access this page is not allowed - how to set handler mappi
...les / roles services / ... whatever else they find good to invent for classifying it. But if the change in web.config made no diff, it means you encounter another issue anyway.
– Frédéric
Sep 11 '14 at 15:10
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How to pass prepareForSegue: an object
...ew controllers. The first contains three buttons and the second needs to know which of those buttons has been pressed before the transition. You could wire the buttons up to an IBAction in your code which uses performSegueWithIdentifier: method, like this...
// When any of my buttons are pressed...