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使用CSplitterWnd实现拆分窗口（多视图显示） - C/C++ - 清泛网 - 专注C/C++及内核技术
...用户可以缩放各行各列。一个静态拆分窗口最多可以包含16行16列。
要找一个使用了静态拆分窗口的应用程序，只要看一下windows管理器即可。
动态拆分窗口最多可以有两行两列，但它们可以相互拆分和合并。Vc就使用了动态拆...
How to navigate through a vector using iterators? (C++)
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112
You need to make use of the begin and end method of the vector class, which return the iterato...
Android ImageView Zoom-in and Zoom-Out
...ss Zoom extends View {
private Drawable image;
ImageButton img,img1;
private int zoomControler=20;
public Zoom(Context context){
super(context);
image=context.getResources().getDrawable(R.drawable.j);
//image=context.getResources().getDrawable(R...
How can I get a Bootstrap column to span multiple rows?
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167
For Bootstrap 3:
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/boots...
Find the files existing in one directory but not in the other [closed]
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14 Answers
14
Active
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Drop data frame columns by name
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You can use a simple list of names :
DF <- data.frame(
x=1:10,
y=10:1,
z=rep(5,10),
a=11:20
)
drops <- c("x","z")
DF[ , !(names(DF) %in% drops)]
Or, alternatively, you can make a list of those to keep and refer to them by name :
keeps <- c("y", "a")
DF[keeps]
EDIT ...
What MySQL data type should be used for Latitude/Longitude with 8 decimal places?
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610
DECIMAL is the MySQL data-type for exact arithmetic. Unlike FLOAT its precision is fixed for an...
Virtualbox “port forward” from Guest to Host [closed]
...t and find out the ip address:
ifconfig
example of result (ip address is 10.0.2.15):
eth0 Link encap:Ethernet HWaddr 08:00:27:AE:36:99
inet addr:10.0.2.15 Bcast:10.0.2.255 Mask:255.255.255.0
Go to Vbox instance window -> Menu -> Network adapters:
adapter should be NAT
cli...
How to log cron jobs?
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* * * * * myjob.sh >> /var/log/myjob.log 2>&1
will log all output from the cron job to /var/log/myjob.log
You might use mail to send emails. Most systems will send unhandled cron job output by email to root or the corresponding user.
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Returning JSON from PHP to JavaScript?
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194
Php has an inbuilt JSON Serialising function.
json_encode
json_encode
Please use that if y...