nsstring

一、介绍 在OC中我们可以给任意的一个类以@property的格式声明属性，当然对于这个属性也会采用某一些属性关键字进行修饰，那么属性的真正的面目是啥样子的呢？其实，runtime源码中可以看到，property是一个结构，如下所示，只不过苹果为这个结构体另外定义了一个结构体指针。 //属性结构体指针 typedef struct objc_property *objc_property_t; 二、函数 正如我们所知，MJExtension是一个非常流行的json解析框架，其内部对对象的每一个属性进行解析的方式其实就是通过runtime来实现的。runtime源码中提供了属性的相关API函数。通过这些函数，我们可以轻松的得到每一个属性名和类型以及特性，相关函数如下： //获取一个属性 objc_property_t _Nullable class_getProperty(Class _Nullable cls, const char * _Nonnull name); //添加一个属性 class_addProperty(Class _Nullable cls, const char * _Nonnull name, const objc_property_attribute_t * _Nullable attributes,unsigned int attributeCount)

I am trying to find the accepted formats on an AVFoundation output: self.theOutput=[[AVCaptureVideoDataOutput alloc]init]; if ([self.theSession canAddOutput:self.theOutput]) [self.theSession addOutput:self.theOutput]; I am then inserting a breakpoint right after and: po [self.theOutput availableVideoCVPixelFormatTypes] and I get this: (NSArray *) $5 = 0x2087ad00 <__NSArrayM 0x2087ad00>( 875704438, 875704422, 1111970369 ) How do I get the string values of these format types? Thanks On an iPhone5 running iOS6, here are the AVCaptureVideoDataOuput availableVideoCVPixelFormatTypes:

I see some UIStringDrawing methods have been updated to use NSLineBreakMode instead of UILineBreakMode in iOS 6.0: E.g. - (CGSize)sizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size lineBreakMode:(NSLineBreakMode)lineBreakMode How can I check for this to ensure my iOS 5 users and below continue to use UILineBreakMode? No checking is necessary. These are just enums and they map to the same values You can see there is no real difference here: UILineBreakMode vs NSLineBreakMode enum { NSLineBreakByWordWrapping = 0, NSLineBreakByCharWrapping, NSLineBreakByClipping,

How can I count the occurrence of a character in a string? Example String: 123-456-7890 I want to find the occurrence count of "-" in given string You can simply do it like this: NSString *string = @"123-456-7890"; int times = [[string componentsSeparatedByString:@"-"] count]-1; NSLog(@"Counted times: %i", times); Output: Counted times: 2 This will do the work, int numberOfOccurences = [[theString componentsSeparatedByString:@"-"] count]; I did this for you. try this. unichar findC; int count = 0; NSString *strr = @"123-456-7890"; for (int i = 0; i<strr.length; i++) { findC = [strr

SO I wish to check to see if the item in my array [clientDataArray objectForKey:@"ClientCompany"] is nil . temp = [clientDataArray objectForKey:@"ClientCompany"]; if (temp != [NSNull null]) infofieldCompany.text = temp; So far I have been able to achieve this through the above code, but it does give me the warnings warning: NSArray may not respond to -objectForKey: warning: comparison of distinct Objective-C types struct NSNull * and struct NSString * lacks a cast My main interest is the second warning, but the first warning also interest me. How should I adapt my above code? Your first

I'm running the following code in the viewDidLoad function of a vanilla iPad single view app: /* * Print the string. A lot. */ for (int i = 0; i < 300; i++) { NSLog(@"%d\n", i); NSLog(@"⊢ ⊣ ⊥ ⊻ ⊼ ⊂ ⊃ ⊑ ⊒ \n"); } The output looks like this: 2013-02-04 20:17:49.718 testplay[59585:c07] 228 2013-02-04 20:17:49.718 testplay[59585:c07] ⊢ ⊣ ⊥ ⊻ ⊼ ⊂ ⊃ ⊑ ⊒ 2013-02-04 20:17:49.719 testplay[59585:c07] 229 2013-02-04 20:17:49.719 testplay[59585:c07] ⊢ ⊣ ⊥ ⊻ ⊼ ⊂ ⊃ ⊑ ⊒ 2013-02-04 20:17:49.719 testplay[59585:c07] 230 2013-02-04 20:17:49.720 testplay[59585:c07] ⊢ ⊣ ⊥ ⊻ ⊼ ⊂ ⊃ ⊑ ⊒ 2013-02-04 20:17:49.720

Trying to convert a string to NSURL and this is not happening. barcodeTextLabel.text = foundCode.barcodeString; urlToGrab = [NSString stringWithFormat:@"%@", foundCode.barcodeString]; // foundCode.barcodeString is an NSString urlToGrab shows the following "error invalid CFStringRef" Dimme This is how you create an NSURL from an NSString : NSURL *url = [NSURL URLWithString:@"http://www.google.com"]; swapnali patil You can use following for creating the file path to url. NSURL *yourURL = [NSURL fileURLWithPath:@"/Users/xyz/Desktop/abc.sqlite"]; If foundCode.barcodeString is the string you want