In MS visual studio we just right click add watch.
How does one do this in Xcode?
Use the po command in the Debug area
Set up a breakpoint on the relevant area of code, then when the program stops at the breakpoint, enter commands in the Console in the Debug Area.
The relevant command is po (print object) followed by the expression you want to evaluate.
If the Debug window is not visible in XCode, you can show it via the top menu:
'View' -> 'Debug Area' -> 'Activate Console' (XCode v8.x)
Example
To evaluate an expression like var1/var2 where var1 and var2 are both doubles, enter the following in the Console:
po var1/var2
The Console will return something like:
(double) $2 = 3.085 [no Objective-C description available]
Showing object properties
You can also return a particular property of an object currently used in the code at that breakpoint:
po [bankInfo city]
And it will return something like:
(id) $4 = 0x000069e8 Testville
Note though that the Console doesn't seem to like the dot notation and prefers the square brackets when applicable. For example, this returns an error for me:
po bankInfo.city
I hope this is what you've been looking for.
Gabe's answer is almost there but missing one crucial detail: Select Debugger Output . By default the bottom option is set to Target Output, so the po command doesn't show you anything.
Here is a sandwich app from a tutorial I'm debugging:
Being an xcode newbie and coming from a MS Visual Studio Background, I wanted exactly what the OP was looking for. While playing around from reading Gabe's answer I selected Debugger Output and got what I wanted.
My seniors told to use NSLog(#variable)..........
Set some breakpoints in the begginning of the looping and functions. Once u click on the breakpoint(one similar to arrow) button in the editor window the "Build and debug tool" will get enabled. You can then go to the debugger by clicking the debugger icon. on the right of the debugger window variables will be visible select self->then the instance variable u r going to set watch point.Right click on that and select "watch variable".A trigger point will be set and you will be notified with the value of the variable when changed.
As fas as i understand you would like to see when a variable is changing. For this make a breakpoint and right click on it and choose Edit Breakpoint. A window will appear:
Make sure you choose the right action like Debugger Command or Log Message and check the tick down at the options Automatically continue after evaluating. So you get some kind of action (e.g. logging, sound, etc) and wont stop at the breakpoint.
If you want to know when the variable changes, use a "watch":
Set a breakpoint somewhere in the class in question;
Run the app in the debugger and let it stop at your breakpoint; and
Go to the "Variables" view in the left side of the bottom "Debug" panel and right click on the property in question and choose "Watch".
For example, here, I've stopped at a breakpoint in viewDidLoad, and added a "watch" for total:
(This is Swift, but the same is true for Objective-C, too.)
Now, if I "continue" execution (), Xcode will pause whenever this property changes and I can see at what line of code total is changing, the stack trace to get to that point, etc.
Related
When running a program I need to see every time a certain button is disabled and step through the code at that point.
If I set a breakpoint with a condition
(ex: only hit when button1.enabled=false) it will only hit in that specific place.
Is it possible to set a breakpoint on the entire program so that i can see when a condition changes across many forms and locations?
You can't set one breakpoint and have it apply to every line of the file, but you can set a breakpoint on the setter of Enabled and then filter it to a specific filter condition. That would give you the desired result. (Note, you might need to turn off "Just my code", see this question for more info)
Set a breakpoint using the "New Breakpoint At Function" as described here, though in Visual Studio 2013, I seem to need to use a slightly different notation:
Then set the breakpoint to funtion:
System.Windows.Forms.Control.Enabled
in C# or for VB.NET:
System.Windows.Forms.Control.set_Enabled(bool)
(You seem to need to use the class that actually defines the property, which in case of the Button class' Enabled property, is the Control class the Button inherits from.
Ignore the warning about it not being able to find the function (it does that for properties somehow), or uncheck the Intellisense lookup.
Now look up the breakpoint in the Breakpoints list and customize the condition so it breaks on the right button
Use the Name property (or any other filter that makes the breakpoint unique) to trigger when you need it to:
When it breaks, it will break in the sources of Control (if you have Framework Source Stepping enabled), which may be confusing. Use the Stack Trace window to find the location where the method was invoked exactly.
Another way of setting the breakpoint is through the Stacktrace window. Set a breakpoint on any line that has your property of interest on it. Launch the debugger and make it break on that line, now use "Step into Specific" to step into the property that you want to break on.
Use the "Stack" window to generate the breakpoint for you:
Since in your case you're looking to break on a function from the Microsoft .NET framework, there is another way. Enabled Framework Source Stepping.
Open the Visual Studio Debugger options and enable "Framework Source Stepping" and disable "Just My Code".
Then enable the Microsoft Symbol Servers in as instructed. Now load up your application under the debugger and wait for the symbol files to be downloaded.
set a break point anywhere in your code that is somehow related to System.Windows.Forms (The constructor of your MainForm for example) and rightclick any function from the "System.Windows.Forms" assembly to load the symbols for that assembly. This will allow you to step into the "Enabled" property and set a break point there.
A full tutorial can be found here:
http://blogs.msdn.com/b/sburke/archive/2008/01/16/configuring-visual-studio-to-debug-net-framework-source-code.aspx
Apologies upfront if this is a silly question, but it's annoying me to no end and I can't figure it out.
I'm using Visual Studio 2013 Professional, and I usually code in C# where when using the Intellisense, when I press Enter to select a method or something it adds my selection and I can continue typing on the same line.
But at the moment I'm working on a project which is in VB.NET, and when I use the Intellisense in the same way it puts my cursor in the next line, i.e. I press Enter to select whatever, it adds my selection and starts a new line, so I have to press the Backspace to go back to the previous line. It's so annoying!
Is there a way to change this behaviour so the cursor doesn't go to the next line? I've looked at the settings available in Tools > Options but can't figure it out, and searching Google for anything similar hasn't been successful.
Found it here (paragraph List Members)
You have toggled to suggestion mode instead of completion mode.
You can also change to suggestion mode, in which only the text you type is inserted into the code. For example, if you enter an identifier that is not in the list and press TAB, in completion mode the entry would replace the typed identifier. To toggle between completion mode and suggestion mode, press CTRL+ALT+SPACEBAR or click Edit/IntelliSense/Toggle Completion Mode.
So, either use TAB/SPACEBAR (as I said in the comment) or press CTRL+ALT+SPACEBAR to switch back to completion mode.
EDIT: I've found out that whenever you type Stri (String will show highlighted in the list now) and you press . (dot) it will autocomplete and stay at the same line.
I think your way of doing this in C# isn't possible in Visual Basic.
I had the same problem and discovered that Auto list members was not enabled on my machine. It's under Tools > Options > Text Editor > Basic > General. This gave me the intellisense I was looking for.
Simple thing which can be used when you face this kind of issue is to press
tab key instead of Enter key when the IntelliSense provided me prediction list.
Some part of a big code base is printing out weird NSLog statements, and I'm trying to detect where it's coming from. Is there a way to put 1 breakpoint at the start of every NSLog call so I can see where it's being called from, rather than manually have to put breakpoints on all places that call NSLog?
In Xcode 6:
Step 1:
On the Navigator on the left, go to Breakpoint Navigator (command ⌘ + 7):
Step 2:
Click the + button on the bottom left (Add a new breakpoint),
then choose Add Symbolic Breakpoint...:
Step 3:
In Symbol, type NSLog.
Alternatively, you can do the same thing in Debug → Breakpoints → Create Symbolic Breakpoint.
Fo Xcode 5, see this.
If you want to break on a certain log message you can use:
This example will break on every log containing the word "Warning".
Update:
On newer devices use $x0.
Simulator and older use $r0.
$arg0 should do for all cases.
In the breakpoint navigator (command+6) add (on the bottom, there is a Plus symbol) a symbolic breakpoint and use NSLog as symbol.
According to this you can set that kind of breakpoint by doing so in the lldb console:
breakpoint set --name NSLog
One way to do this using Xcode could be to put a breakpoint in the main function or on you AppDelegate applicationDidFinishLaunchin (read: as soon as possible).
Then, you run your app, and when it pauses on said breakpoint, you have access to the lldb console: you type the above line and hit return, and lldb prints something like this:
Breakpoint 3: where = Foundation`NSLog, address = 0x32a3da08
At this point, you resume your app, and it will pause again when NSLog is called (pay attention to the call stack using the Debug Navigator).
I'm trying to watch a variable with Xcode. I'm following the instructions in here by pausing at a breakpoint, selecting Run > Variables View > .... but with the exception of "Enable Data Formatters" the rest of the options are all greyed out. Any ideas?
I'm using Xcode version 3.1.3.
I haven't gotten watchpoints created from the Run menu to work for me either, unfortunately. One thing to be aware of is that when a variable goes out of scope, the watchpoint may become invalid.
If you don't mind getting a little more in-depth, you can use some low-level gdb commands to set a watchpoint for the address of the memory itself. For example, in the guide you linked to, they show how to watch the variable path which is a pointer with the value 0xbfffeb70. To manually set a watchpoint for that address, click in the debugger console (where the debugging output is printed) after the "(gdb)" prompt and type something like this:
watch *((int*)0xbfffeb70)
The cryptic syntax is necessary because gdb expects inputs as C expressions. For a little more detail, visit this link and jump to the section titled "Using hardware watchpoints". (I'm testing on an Intel machine, not sure how PowerPC handles it.) When you set watchpoints this way, Xcode will alert you with a drop-down sheet when a watchpoint is reached and tell you how the value was changed, and gdb will print the same info in the console.
I just ran into this problem. Here is a solution: right click on the variable name and select "View variable in window" from the menu which appears. It should be near the bottom.
Add a breakpoint. Right click in the watch list of the debug area and choose "Add expression..."
If you are getting a different menu, you have to click off of the currently highlighted variable so that nothing is highlighted when you right click.
The Answers given here only work if you use the gdb compiler. For those of you who are looking for an option to set a watchpoint with the lldb compiler I have bad news:
It's not working jet (XCode 4.3.2 with lldb 3.1) even though the lldb docs say you can.
Check out this Email. The lldb commands compared to the gdbs can be found here
I was trying to figure this out in XCode 5. I finally found a "Variables view" button at the bottom right of the output console. It's the little rectangle that will be gray on the left, white on the right if it's not enabled. I'm not sure if this is in XCode 3, but I expect most people have upgraded anyway.
I have a project in SSIS and I've added an Execute SQL Task which sends its result out to a variable. I wanted to confirm the value because I was worried that it would try to write it out as a resultset object rather than an actual integer (in this case I'm returning a COUNT).
My first thought was just to run it in debug mode and add the global variable to my Watch window. Unfortunately, when I right-click on the Watch window, the option to "Add Variable" is greyed out. What am I missing here?
I've gotten around confirming that my variable is set correctly, so I'm not interested in methods like putting a script in to do a MsgBox with the value or anything like that. For future reference I'd like to be able to watch variables in debug mode. If there are some kind of constraints on that then I'd like to know the what and why of it all if anyone knows.
The help is woefully inadequate on this one and every "tutorial" that I can find just says, "Add the variable to the Watch window and debug" as though there should never be a problem doing that.
Thanks for any insight!
I believe you can only add variables to the Watch window while the debugger is stopped on a breakpoint. If you set a breakpoint on a step, you should be able to enter variables into the Watch window when the breakpoint is hit. You can select the first empty row in the Watch window and enter the variable name (you may or may not get some Intellisense there, I can't remember how well that works.)
Drag the variable from Variables pane to Watch pane and voila!
I know this is very old and possibly talking about an older version of Visual studio and so this might not have been an option before but anyway, my way would be when at a breakpoint use the locals window to see all current variable values ( Debug >> Windows >> Locals )
Visual Studio 2013: Yes to both adding to the watch windows during debugging and dragging variables or typing them in without "user::". But before any of that would work I also needed to go to Tools > Options, then Debugging > General and had to scroll right down to the bottom of the right hand pane to be able to tick "Use Managed Compatibility Mode". Then I had to stop and restart debugging. Finally the above advice worked. Many thanks to the above and to this article: Visual Studio 2015 Debugging: Can't expand local variables?