大约有 48,000 项符合查询结果（耗时：0.0843秒） [XML]
Detect backspace in empty UITextField
...ss UITextField and implement canPerformAction:withSender: to return NO for select: and selectAll: actions when the text is equal to the string @"\u200B".
– ma11hew28
Oct 19 '11 at 21:56
...
How to use pull to refresh in Swift?
...ring(string: "Pull to refresh")
refreshControl.addTarget(self, action: #selector(self.refresh(_:)), for: .valueChanged)
tableView.addSubview(refreshControl) // not required when using UITableViewController
}
@objc func refresh(_ sender: AnyObject) {
// Code to refresh table view
}
At s...
How to call methods dynamically based on their name? [duplicate]
... each with their own advantages and disadvantages. Care should be taken to select the most appropriate method for the situation.
The following table breaks down some of the more common techniques:
+---------------+-----------------+-----------------+------------+------------+
| Method | A...
Is there any way to prevent input type=“number” getting negative values?
...tive number from keyboard.
Solution is to prevent with key code:
// Select your input element.
var number = document.getElementById('number');
// Listen for input event on numInput.
number.onkeydown = function(e) {
if(!((e.keyCode > 95 && e.keyCode < 106)
|| (e....
Using different Web.config in development and production environment
... test, staging and production) we developed a system where the application selected the appropriate configuration based on the machine name it was deployed to.
This worked for us because:
administrators could deploy applications without involving developers (a requirement) and without having to f...
Ternary operator in AngularJS templates
... above creates an object with two properties. The array syntax is used to select either the property with name true or the property with name false, and return the associated value.
E.g.,
<li class="{{{true: 'myClass1 myClass2', false: ''}[$first]}}">...</li>
or
<li ng-class="{tru...
Is it possible to break a long line to multiple lines in Python [duplicate]
...or you will get a list of strings instead of one long string:
queryText= "SELECT * FROM TABLE1 AS T1"\
"JOIN TABLE2 AS T2 ON T1.SOMETHING = T2.SOMETHING"\
"JOIN TABLE3 AS T3 ON T3.SOMETHING = T2.SOMETHING"\
"WHERE SOMETHING BETWEEN <WHATEVER> AND <WHATEVER ELSE>"\
"ORDER BY WHATEVERS DE...
Find all records which have a count of an association greater than zero
...> 17
[14] pry(main)> Article.joins(:comments).distinct.to_sql
=> "SELECT DISTINCT \"articles\".* FROM \"articles\" INNER JOIN \"comments\" ON \"comments\".\"article_id\" = \"articles\".\"id\""
share
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psql: FATAL: database “” does not exist
...euser --interactive
When prompted for role name, enter linux username, and select Yes to superuser question.
Still logged in as postgres user, create a database: createdb <username_from_step_3>
Confirm error(s) are gone by entering: psql at the command prompt.
Output should show psql (x.x.x) T...
Changing the default header comment license in Xcode
...o change the organization name in Xcode click on the project file so it is selected (left sidebar of Xcode in the Project navigator) > In the File Inspector (right sidebar of Xcode) change the Organization text box.
sha...