I am trying to output general data (source code) from a website, but it just sits there. Can't figure out if its the interface or the code. Would someone double-check for me?
#import "Lockerz_RedemptionViewController.h"
#implementation Lockerz_RedemptionViewController
-(IBAction)start: (id) sender {
while (1) {
NSMutableData *mydata = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:#"http://ptzplace.lockerz.com/"]];
NSString *output = [[NSString alloc] initWithData:mydata encoding:NSASCIIStringEncoding];
NSLog(output);
}
}
The reason your NSLog doesn't work is it should use format strings.
Replace:
NSLog(output);
With:
NSLog(#"%#",output);
For more info see http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/Strings/Articles/FormatStrings.html
Why the while(1)? Are you intentionally trying to set up an infinite loop? You should just run this once, or maybe set up a periodic timer to reload it every few seconds, but certainly don't use an infinite loop for that... also it's been a while since I did anything with Cocoa networking, but you might want to look into NSURLRequest. You also may want to try NSData's dataWithContentsOfURL:options:error: and check the error parameter to better see what might be going wrong. Hope this helps you out.
Related
I have this code snippet below. The purpose is to write the contents of an array to a plist file. When I run this I don´t get any errors and everything seems to be fine. The problem is that the file doesn´t appear on the desktop. I used writeToFile before in other projects without any problems. What is wrong with it? Greetings from Switzerland, Ronald Hofmann.
- (IBAction) doActionPlist: (NSButton *) sender
{
NSString *fileExt = #".plist";
NSArray *myResultArray = [NSArray arrayWithObjects:
#"Product Number Unlimited Desktop:",
#"4DDP120-UUS001-ANLKR-17C6B",
#"4DDP130-UUS001-ANQEI-1BC12",
#"4USE120-UUS001-80BY1-1EAB0",
#"4USE130-UUS001-6NTUE-11D64",
#"qA0iHnw4EIgOALgAAAQCmUtj",
#"qA0iHnw6EIgAALgAAPUBhByg",
#"4DDP11U00USN001",
#"4DDP13U12USN001",
#"4UCL00U00USN001",
#"4UCL00U00USN010",
#"4UCL11U00USN001",
#"4UCL11U00USN010",
#"4UCL12U11USN001",
#"4UCL12U11USN010",
#"4UCL13U12USN001",
#"4UCL13U12USN010",
#"4USE12U11USN002",
#"4USE13U12USN002",
#"4UWE13U12USN999",
nil];
NSString *thePath = [NSString stringWithFormat:#"/Users/ronny/Desktop/Testfile%#",fileExt] ;
[myResultArray writeToFile:thePath atomically:YES] ;
}
Unfortunately, it can be difficult to debug this call because it only returns YES or NO with no further information about why it succeeded or failed. The fact that it's not throwing any exceptions doesn't necessarily mean that nothing is going wrong; it just means that NSArray can't be bothered to tell you about it.
If you're really at wit's end, you might try converting your NSArray to NSData using NSPropertyListSerialization and then using writeToFile:options:error instead. If you do this, post the error message and someone should be able to offer better debugging advice.
NSString *stringURL=[[NSString alloc] init];
stringURL=[stringURL stringByAppendingFormat:kSearchBarURL,text.text];
NSString *url = [NSString stringWithString:stringURL];
NSData *data1 = [NSData dataWithContentsOfURL:[NSURL URLWithString:url]];
NSString *responseids = [[NSString alloc] initWithData:data1 encoding:nil];
responseids = [responseids stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:#"\n\r\t"]];
SBJsonParser *parser=[SBJsonParser new];
NSData *data = [parser objectWithString:responseids error:nil];
NSMutableDictionary *searchURL = (NSMutableDictionary*)data;
I coded this i did not handle the exception for my code.
doing json and calling the service url and loading the data.
the application get crashes when my service is too low or no service found.
How to handle the exception for my code here..
Do I use #try #catch.
or
NSURLConnection for error handling.
Please help me out .
Thanks in advance.
Whenever an API makes use of NSError, you should use this rather than wrapping things up in a try…catch block as NSError is designed exactly for this. I usually reserve #try for things where I am really not able to anticipate what might go wrong. If NSError is in the mix, then you know that there is a potential for a problem that you should be handling gracefully.
More generally, your code has some strange stuff in it. You alloc init an empty NSString and then create a new string by appending a format. Not sure why you don't just use [NSString stringWithFormat]. Once you have the string, you can create the URL without the NSString *url bit.
You're also using a synchronous call to what I assume is a remote server. This has the potential to bog down your application if/when the server is not available. You're also not telling NSString what kind of encoding you expect your string to be in when it reads it from NSData. A better method depending on your server side would be to use NSString's stringWithContentsOfURL:usedEncoding:error: method. I would recommend that you use the various NSURLConnection callbacks. Have a look at the URL Loading System Programming Guide on Using NSURLConnection The NSURLConnection delegate methods are the ones you want to implement to provide this asynchronous processing.
For your trimming, you might be interested in the +whitespaceAndNewlineCharacterSet method on NSCharacterSet.
Finally, for your JSON parsing, you might be interested in the category that the SBJSON code adds to NSString, particularly -JSONValue which will give you the dictionary or array representation (as appropriate) of the NSString when parsed as JSON by SBJSON.
HTH
I have been searching for many days on how to save my apps data. I found some stuff but it was very complicated and badly explained. I need that when I completely close my apps all the data I entered in the text field are still there when I open my apps again. I tried a tutorial but this only let me save about 8 textfields and I need to save thousands I am starting Objective-C and Xcode so if somebody want to give me an answer please make it very precise.
Alright, what I'd suggest would be putting all the data from your text fields into an array and saving that to a file, then loading it when you re-open the app.
The first thing you need is a save file. This function will create one for you.
-(NSString*) saveFilePath{
NSString* path = [NSString stringWithFormat:#"%#%#",
[[NSBundle mainBundle] resourcePath],
#"myfilename.plist"];
return path;}
Now that that's done you need to create your saving array. Hopefully you have your thousands of textfields already fitted into an array of some sort. If not, this will be a painful process regardless of how you tackle it. But anyway... (Here, labelArray will be the array of all your text fields/labels/etc.)
NSMutableArray* myArray = [[NSMutableArray alloc]init];
int i = 0;
while(i < labelArray.count){
[myArray addObject: [labelArray objectAtIndex: i].text];
i ++;
}
[myArray writeToFile:[self saveFilePath] atomically:YES];
[myArray release];
And the loading code would be something along the lines of
NSMutableArray* myArray = [[NSMutableArray arrayWithContentsOfFile:[self saveFilePath]]retain];
Then you'd simply load the data back into your array of text fields.
Hope this helps.
It sounds like your application architecture may be unsound if you are planning on saving thousands of text fields' data in the fraction of a second you get while your app is closing. It would probably be better to save these as the user enters the data instead of waiting to save all the data at once.
To get the path you are going to write ( or read from! ) to, you do the following:
NSString *writableDBPath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:#"MyFile.extension"];
And then use a method like "writeToFile:automically:" of NSString or NSDictionary etc. to write to the path.
My tableview is get XML data from URL,First I declare a NSMutableArray *dataArray;
and this is how I get the data in my TableviewSample.m
- (void)getDataFromURL{
NSString *theURLAsString = [NSString stringWithFormat:GetAllData];//<-EXE_BAD_ACCESS HERE
//#define stringWithFormat:GetAllData #"http://192.168.10.28/req_alldata.php"
NSURL *theURL = [NSURL URLWithString:theURLAsString];
self.dataArray = [NSMutableArray arrayWithContentsOfURL:theURL];
}
Then I just get the elements form this array to my tableview ...
But here I have to say one more thing , actually it won't crash before I add another view...
I add a bar button to go to a webView , this webView is use to load a IP Cam stream video
When I back to the tableview , It will appear EXC_BAD_ACCESS
This is odd things I cannot to solve it...because both side code are all looks normal
If I remove this webview ,no matter how I run the program ,it won't crash...
And sometimes I leave the webView I will receive memory warning :level 2
But just only one time.
or do I use a wrong way to open an ip cam stream ???
Thanks for all reply : )
OK,here is the code different I use in my webview class
This is first version I use
- (void)viewDidAppear:(BOOL)animated{
NSString *directGoToWebCam = [NSString stringWithFormat:GetAllData];
self.IPCamWebView=[[[UIWebView alloc] initWithFrame:CGRectMake(0,0,640,960)] autorelease];
[self.IPCamWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:directGoToWebCam]]];
[self.view addSubview:self.IPCamWebView];
}
Where does GetAllData come from? It looks like that isn't pointing to anything. More code, the exact error, and a more careful description will go a long way here.
It probably has something to do with the use of #define which does not say anything about the type of the object you are using.
If you want to define a constant string in your code the best would be to use something like this:
static NSString *GetAllData = #"192.168.10.28/req_alldata.php";
Where you need to use the string you can simply write:
NSString *GoToWebCam = [NSString stringWithString:GetAllData];
I have a problem where I have sound in Menu > Level one.
However when I exit Level one and go back to menu the sound won't stop!
What code do I need to terminate the sound?
This is the code I'm using:
- (IBAction) playsound {
NSString *path = [[NSBundle mainBundle] pathForResource:#"imsound" ofType:#"wav"];
AVAudioPlayer* myAudio=[[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL];
myAudio.delegate = self;
myAudio.volume = 1.0;
myAudio.numberOfLoops = -1;
[myAudio play];
}
As the documentation states, -1 will cause it to play repeatedly until you send it a -stop. So the problem becomes "when should I tell it to stop." It's probably a good idea to do so (if it's playing) when you go back.
Because you don't hold a reference to the player (you're leaking it as soon as you leave the -playSound: method, you have no way to tell it to shut up. You should make it an instance variable / property so you can get to it whenever you need to. You're essentially pressing play then tossing the player into the back of someone's truck, then wanting it back so you can turn it off. Should've tied a string to it. ;-)
Proper memory management techniques and use of instance variables are the key causes of your current woes.