Tutorial by Examples: app

Let's say you're working on an app called MyTasks, and you want to allow inbound URLs to create a new task with a title and a body. The URL you're designing might look something like this: mytasks://create?title=hello&body=world (Of course, the text and body parameters are used to populate our...

NSLog is good, but you can also log by appending to a file instead, using code like: NSFileHandle* fh = [NSFileHandle fileHandleForWritingAtPath:path]; if ( !fh ) { [[NSFileManager defaultManager] createFileAtPath:path contents:nil attributes:nil]; fh = [NSFileHandle fileHandleForWriting...

There are frequent behavior patterns that can result in a lot of boilerplate code. By declaring a method that takes a Closure as a parameter, you can simplify your program. As an example, it is a common pattern to retrieve a database connection, start a transaction, do work, and then either commit ...

The following commands can be used to swap the names of two MySQL databases (<db1> and <db2>): mysqladmin -uroot -p<password> create swaptemp mysqldump -uroot -p<password> --routines <db1> | mysql -uroot -p<password> swaptemp mysqladmin -uroot -p<password&gt...

Make sure the following dependency is added to your app's build.gradle file under dependencies: compile 'com.android.support:support-core-ui:24.2.0' Then add the SwipeRefreshLayout in your layout: <android.support.v4.widget.SwipeRefreshLayout android:id="@+id/swipe_refresh_layo...

Use the following piece of code to set the badge number from within your application (suppose someNumber has been declared before): Objective-C [UIApplication sharedApplication].applicationIconBadgeNumber = someNumber; Swift UIApplication.shared.applicationIconBadgeNumber = someNumber In order ...

A lot of people who are new to multi-threading think that using threads automatically make an application go faster. In fact, it is a lot more complicated than that. But one thing that we can state with certainty is that for any computer there is a limit on the number of threads that can be run at ...

You can use the heroku create command to create a Heroku application. Each application you deploy to Heroku has its own code base, environment variables, addons, etc. Each Heroku application has a globally unique name. If you try to create a Heroku application whose name is already taken, you will ...

The standard Java toolchain (and 3rd-party tools designed to interoperate with them) have specific rules for mapping the names of classes to the pathnames of files and other resources that represent them. The mappings are as follows For classes in the default package, the pathnames are simple fi...

TextViewPlus.java: public class TextViewPlus extends TextView { private static final String TAG = "TextView"; public TextViewPlus(Context context) { super(context); } public TextViewPlus(Context context, AttributeSet attrs) { super(context, attrs)...

Tags are typically applied via the editor; however, you can also apply tags via script. Any custom tag must be created via the Tags & Layers window before being applied to a game object. Setting Tags in the Editor With one or more game objects selected, you can select a tag from the inspecto...

As described in the remarks section you can specify the Gradle version used by each project editing the Gradle distribution reference in the gradle/wrapper/gradle-wrapper.properties file. For example: ... distributionUrl = https\://services.gradle.org/distributions/gradle-2.14.1-all.zip ... ...

For those of us using Maven as a build system, we can use the Maven Archetype to create a new application. First consult the maven archetype catalog mvn archetype:generate -DarchetypeCatalog=http://struts.apache.org/ you can use one of the following achetypes: The Blank Convention Archetype (s...

One of the more annoying things that programmers can do is to scatter calls to printStackTrace() throughout their code. The problem is that the printStackTrace() is going to write the stacktrace to standard output. For an application that is intended for end-users who are not Java programmers,...

What's the deal with the following? julia> @test 0.1 + 0.2 == 0.3 Test Failed Expression: 0.1 + 0.2 == 0.3 Evaluated: 0.30000000000000004 == 0.3 ERROR: There was an error during testing in record(::Base.Test.FallbackTestSet, ::Base.Test.Fail) at ./test.jl:397 in do_test(::Base.Test....

Consider these two pieces of code: int a = 1000; int b = a + 1; and Integer a = 1000; Integer b = a + 1; Question: Which version is more efficient? Answer: The two versions look almost the identical, but the first version is a lot more efficient than the second one. The second version is...

This code uses the top level Application object to minimize the main Excel window. Sub MinimizeExcel() Application.WindowState = xlMinimized End Sub

int i; int n = 1000000; double area = 0; double h = 1.0 / n; #pragma omp parallel shared(n, h) { double thread_area = 0; // Private / local variable #pragma omp for for (i = 1; i <= n; i++) { double x = h * (i - 0.5); thread_area += (4.0 / (1.0 ...

double area; double h = 1.0 / n; #pragma omp parallel for shared(n, h, area) for (i = 1; i <= n; i++) { double x = h * (i - 0.5); #pragma atomic area += (4.0 / (1.0 + x*x)); } pi = h * area; In this example, each threads execute a subset of the iteration count and they accumula...

double area; double h = 1.0 / n; #pragma omp parallel for shared(n, h, area) for (i = 1; i <= n; i++) { double x = h * (i - 0.5); #pragma omp critical { area += (4.0 / (1.0 + x*x)); } } double pi = h * area; In this example, each threads execute a subset of the iteratio...