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This is a simple example to display read-only data that is tabular in nature using Qt's Model/View Framework. Specifically, the Qt Objects QAbstractTableModel (sub-classed in this example) and QTableView are used. Implementations of the methods rowCount(), columnCount(), data() and headerData() are...

Rust tuples, as in most other languages, are fixed-size lists whose elements can all be of different types. // Tuples in Rust are comma-separated values or types enclosed in parentheses. let _ = ("hello", 42, true); // The type of a tuple value is a type tuple with the same number of el...

To access elements of a tuple directly, you can use the format .n to access the n-th element let x = ("hello", 42, true); assert_eq!(x.0, "hello"); assert_eq!(x.1, 42); assert_eq!(x.2, true); You can also partially move out of a tuple let x = (String::from("hello&quo...

Method references make excellent self-documenting code, and using method references with Streams makes complicated processes simple to read and understand. Consider the following code: public interface Ordered { default int getOrder(){ return 0; } } public interface Valued&lt...

Show how to create simple converter and use ConverterParameter to pass parameter to converter. Multiply value by coefficient passed in ConverterParameter. public class MultiplyConverter : IValueConverter { public object Convert(object value, Type targetType, object parameter, CultureInfo cult...

To change the current bash run these commands export SHELL=/bin/bash exec /bin/bash to change the bash that opens on startup edit .profile and add those lines

This is very useful when setting indent of your code if condition1 if condition2 # some commands here endif endif move your cursor to the 2nd line, then >>, the code will indent to right. Now you can repeat your action by continue to 3rd line, then hit . twice, the result will be if ...

If you use the paste command from your terminal emulator program, Vim will interpret the stream of characters as if they were typed. That will cause all kind of undesirable effects, particularly bad indendation. To fix that, from command mode: :set paste Then move on to insert mode, with i, for...

Static variables and methods are not part of an instance, There will always be a single copy of that variable no matter how many objects you create of a particular class. For example you might want to have an immutable list of constants, it would be a good idea to keep it static and initialize it j...

The AND keyword is used to add more conditions to the query. NameAgeGenderSam18MJohn21MBob22MMary23F SELECT name FROM persons WHERE gender = 'M' AND age > 20; This will return: NameJohnBob using OR keyword SELECT name FROM persons WHERE gender = 'M' OR age < 20; This will return: n...

Some ADO.NET providers (most notably: OleDB) do not support named parameters; parameters are instead specified only by position, with the ? place-holder. Dapper would not know what member to use for these, so dapper allows an alternative syntax, ?foo?; this would be the same as @foo or :foo in other...

User-defined method objects may be created when getting an attribute of a class (perhaps via an instance of that class), if that attribute is a user-defined function object, an unbound user-defined method object, or a class method object. class A(object): # func: A user-defined function object...

If you are unsure which rules to list in your .gitignore file, or you just want to add generally accepted exceptions to your project, you can choose or generate a .gitignore file: https://www.toptal.com/developers/gitignore https://github.com/github/gitignore Many hosting services such as Git...

Use the yum command to manage packages in Enterprise Linux-based operating systems: yum install php This installs a minimal install of PHP including some common features. If you need additional modules, you will need to install them separately. Once again, you can use yum to search for these pac...

The echo setting determines whether command echoing is on or off. This is what a sample program looks like with command echoing on (default): C:\Windows\System32>echo Hello, World! Hello, World! C:\Windows\System32>where explorer C:\Windows\System32\explorer.exe C:\Windows\System32&gt...

Once the type handlers are registered, everything should work automatically, and you should be able to use these types as either parameters or return values: string redmond = "POINT (122.1215 47.6740)"; DbGeography point = DbGeography.PointFromText(redmond, DbGeography.DefaultCoordi...

The most important object in the Browser Object Model is the window object. It helps in accessing information about the browser and its components. To access these features, it has various methods and properties. MethodDescriptionwindow.alert()Creates dialog box with message and an OK buttonwindow....

When INSERTing, you can use OUTPUT INSERTED.ColumnName to get values from the newly inserted row, for example the newly generated Id - useful if you have an IDENTITY column or any sort of default or calculated value. When programatically calling this (e.g., from ADO.net) you would treat it as a nor...

<PropertyGroup> <!-- Definition of a Property named "TestCondition". A PropertyGroup may also be placed inside a Target. --> <TestCondition>True</TestCondition> </PropertyGroup> <!-- This Target will run after the "Clean" Target, su...

For efficiency, data.table offers a way of altering a data.frame or list to make a data.table in-place: # example data.frame DF = data.frame(x = letters[1:5], y = 1:5, z = (1:5) > 3) # modification setDT(DF) Note that we do not <- assign the result, since the object DF has been modifi...