It’s very usual to use encrypted SQLite databases in our Xojo projects where we expect to get the maximum read speed from them. But the truth is that encrypting the data in these databases can introduce a penalty in our queries, both from read and writing/updating data to them. How can we improve this? One technique is the creation of a new in-memory based SQLite database, where we will be able to copy the table (or tables) we are interested in getting the maximum speed possible with. Continue reading to see how to do this.
Comments closedCategory: Tips
sort code tips and tricks
There was a curious question on the forums about what # meant.
And from the way it was asked I could see the asker was thinking “I know what If means but what about that # in front of it?” And that if they knew what the # meant that the entire thing would make more sense.
And that’s a fair thought – except for one problem. The # by itself doesn’t “mean” anything. It isn’t like *, ^, + or – in that sense. It’s not an operator.
Comments closedA reader asked me to clarify something about my previous post. Their question was:
Comments closedWhen MyMethod is written as:
Sub MyMethod( i() as integer ) i = array(10,20,30) system.debuglog CurrentMethodName + " i(0) = " + str(i(0)) + " i(1) = " + str(i(1)) + " i(2) = " + str(i(2)) End SubWhat happens if instead of trying to assign a new array you just alter the values in the array passed in?
Let’s talk about the difference between a “reference type” and the BYREF modifier on a passed parameter.
Comments closedThe only built-in gesture for undo on iOS at the moment is to shake the device. This is not very intuitive to me and I’ve certainly done it by accident many times. The makers of Procreate chose a two-finger tap and have found that their users adapted to it nicely. This gesture is being adopted by more and more iOS developers. Here’s all the code you need to implement the two-finger tap for undo in your Xojo iOS apps.
Comments closedWhen I ask “What kind of variable are you?” I don’t mean “Are you an Integer, a String, a Variant, an Object?”. I am asking “are you a value type or a reference type?”. What’s the difference between the two?
Comments closedPrior to Xojo 2018r3 Window and Canvas both had a Graphics property that you could access and draw to. This was deprecated in 2011 because it had significant performance issues on all platforms. The preferred way to draw your graphics since 2011 has been to use the Window.Paint or Canvas.Paint event handlers and the supplied parameter g As Graphics.
Starting with Xojo 2018r3, this Graphics property was removed from Window and Canvas so if you had code that was still relying on it, that code will no longer compile. Here are some tips on how you can migrate your code to use the Paint event handlers and tell the Canvas to update with a call to Invalidate.
Comments closedWhile at the Xojo Developer Conference in Denver last spring*, we got a lot of great feedback about the features that people needed most from the iOS framework. We managed to sneak a few into recent releases of Xojo; here are three of my favorites!
Comments closedI started learning how to code as a teenager. Back then there weren’t very many programming languages. I remember BASIC, Pascal, Fortran, COBOL, C and a handful of others that were highly specialized. Why so few? Because in the 1970’s, computers just couldn’t do very much compared to today. The available languages were sufficient for the limited tasks computers had been assigned to manage.
Over the last several decades, computer technology has exploded. The smartphone I carry around in my pocket is far more powerful than the fastest computers of my youth. As a teenager, I rarely encountered anything where a computer had played a part. Today the rare encounter would be with things where computers had played no part. Computers handle so many tasks now that, as a natural consequence, there are thousands of programming languages with more appearing every year.
With so many languages, it can be difficult to choose one. What is important in a programming language?
Comments closed