I use sdwebimage and ktphotobrowser for my thumbnail gallery. because I have different galleries I need many sources. But i can't change the datasource in the SDWebImageDataSource.m file
I made a variable named myStr and now i want to get it in the SDWebImageDataSource's init function so i can get data from another source
Is it possible or may I have a change create another function named initWithString then pass my path to that function?
in my viewcontroller I initialize the SDWebImageDataSource as
SDWebImageDataSource *sd = [[SDWebImageDataSource alloc]init];
then i set variable
sd.myStr=#"http://mypath.com";
but I can't get the value of myStr in the init function of SDWebImageDataSource.m file
In Init method, initialize your string by setting an empty string. This will solve your problem. or if you can manage to create custom method [[SDWebImageDataSource alloc]initWithString:#"SOMESTRING"];will also be fine.
Related
I have a variable that is passed between two tableview controllers.The cells in the first tableview have a detail label that is updated by this variable that is passed from the second one. once the string is passed i want it to save and bump out the old string.I would like the variable to stay saved until the app is uninstalled. any idea on how i would do this ? passing the data with protocol. I appreciate any help!
I have define NSArray using
extern NSArray *arName;
in AppDelegate method
and then assign values in Array in AppDelegate. after assign value i easily access values in AppDelegate but when I use this global array in another page control it's shows me error
i don't know the exact problem
is it any other method to define GLOBAL ARRAY ?
You'd be better off in this case using a singleton Objective-C class. Don't use global variables with anything that is derived from NSObject, or the ARC system is unable to automatically keep track of references to the object and you'll get crashes like these.
This may sound a newbie question however I'm new to iOS dev.
I've following code in my project, the project is ARC enabled, and I get error on its execution (bad access), and would like to understand the cause of the problem and solve it.
on some button press following code is invoked in MTClassA.m file
-(void) someMethod
{
for (int i = 0; i < N; i++) {
...
(param1 and param2 are location variables)
...
mFlickr = [[MTFlickr alloc] initWithParam1:param1 param2:mparam2];
mFlickr.delegate = self;
[mFlickr fetchImages];
}
}
in MTClassA.h header file mFlickr is declared as MTFlickr* mFlickr so default it it with __strong qualifier.
the callback function of fetchImages class is following
- (void)didRecieveImageLinksFromFlickr:(NSArray*)response
param1:(NSString*)param1 param2:(NSString*)param2 {
...
}
So basically I would like to know is it correct to create mFlickr objects this way in for loop and expect the callback to work correctly, if no please suggest what need to be changed ?
P.S. Do I need to change mFlickr to local variable ? If yes how should I be guaranteed that param1 and param2 methods are the one's that I've passed for teach iteration in for loop ?
You are creating multiple instances of the mFlickr object within your loop, and presumably assigning them to the same instance variable. Under ARC an assignment to an instance variable will automatically release the previous value, so your mFlickr objects are getting destroyed as soon as they are created (except the last one).
Presumably your mFlickr object is setting itself as a delegate for a URL request, it is probably this callback which is failing since the request's delegate no longer exists.
If you are creating multiple instances you should store them in an array instance variable. The callback should include a reference to the particular instance that has returned, and at this point, you remove it from the array.
You don't need to change the mFLicker to local variable. The only thing that i found in your code wrong is that, you are immediately setting mFlicker to self after initializing it. i think you must want to set the delegate of the mFlicker that you can do it by
[mFlicker setDelegate:self]
Did you set #property for mFlicker?
.h
#property(nonatomic, retain) MTFlickr *mflicker;
.m
#synthesis mflicker;
I also had similar experience, ARC was releasing my object after initialization.
so try changing your code to
self.mFlickr = [[MTFlickr alloc] initWithParam1:param1 param2:mparam2];
mFlickr.delegate = self;
[mFlickr fetchImages];
I am also not sure but i just wanted to provide some help
I'm developing an iPad App and need some help.
Through a button within my App I want to create one object at a time.
So every time the button is touched one object should be created.
The problem I have is: I want to assign each object a dynamic name to identify this object.
This would be something like: form0, form1, form2, ..., formN.
This Name corresponds to an instance variable within every object.
So the form1 instance has a number attribute which is 1.
But how do I assign this form1, form2, etc. to a new instance?
I tried to initialize a new instance with the return of a method which creates the formX-String:
-(NSString*)giveMeName{
NSString* simpleName = #"form";
NSString* newName = [simpleName stringByAppendingString:[NSString stringWithFormat:#"%d", questionCounter]];
return newName;
}
where questionCounter is a variable which holds the int identifier for both formX and the instance number attribute.
But when I want to initialize a new instance with this function as name it's not working:
TSForm* [self giveMeName] = [[TSForm alloc] initWithInt:questionCounter headline:headlineText intro:introText];
Obviously I got something wrong with the inner working of Objective-C.
Please help me out.
what you're trying to do isn't really possible. One way that you could achieve the affect you're looking for is using an NSDictionary. For every TSForm object you create, you add that object to the dictionary with the key of the giveMeName return value.
So you start by creating your dictionary:
NSMutableDictionary *formDict = [[NSMutableDictionary alloc] init];
Then, every time you create an object, add it to the dictionary:
id *newTSForm = [[TSForm alloc] init]; // Or however you create a TSForm
[formDict setObject:newTSForm forKey:[newTSForm giveMeName]];
Then when you want to pull out the form you're looking for, you just ask the dictionary based on the name you provided:
[formDict valueForKey:nameOfForm]; // nameOfForm is the name provided by giveMeName
Hope this helps!
use NSMutableArray and keep adding your items there.
Even if what you are trying to do is technically possible, that's using tricsk in low-level objective-C runtime and KVC stuff and so on for nothing.
Using a simple NSMutableArray to keep track of all you instances (and using the index in the array to know which form you are dealing with) is the way to go.
I don't think you really need your unique identifier stuff for that (if so, you are probably thinking about your project the wrong way), as long as you have a way in your code to differentiate each form and manipulate them (the first form created will then be at index 0, the second at index 1… of your NSMutableDictionary)
If you really need this special unique identifier anyway for some strange reason, you can still use an NSMutableDictionary and use the unique identifier as your key of your dict and the form as the associated value. But you should probably think twice about your architecture ad the real need for this before, as it seems quite strange app architecture/design to do so based on your description of your needs in your question.
What you are looking for is some kind of variable variable, which don't really exist in objective-C.
This question (Objective C Equivalent of PHP's “Variable Variables”) has some different suggestions for getting similar results.
I understand that in Objective-C you declare an array in the header file and interact with it in a class. So far I'm adding things and fetching them fine within a single function. I'm new to the language however and can't figure out how to share that array across other functions.
I'd like to initialize array data in my viewDidLoad and access it from various functions later on. Is this possible and if so what's the best way to do it?
Like you said, declare the array in the view controller's header file and make it a #property. Use alloc-init in the implementation's -viewDidLoad method to set it up. Deallocate it in the dealloc method. Use its property setter (self.array) to retain or assign another array, depending on the #property attribute. Access it directly (array) throughout your methods in your class implementation, and via its property getter (obj.array) from other classes.