笔记

NSString / NSData / char* 类型之间的转换

IOS, 笔记

NSString / NSData / char* 类型之间的转换

  • NSString 转化为 char *
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NSString * str＝ @“Test”;
const char * a =[str UTF8String];
  • char * 转化为 NSString
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NSString *str=[NSString stringWithCString  encoding:NSUTF8StringEncoding];
  • char * 转化 NSData
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方法一：
   char * a = (char*)malloc(sizeof(byte)*16);
   NSData *data = [NSData dataWithBytes: a   length:strlen(a)];
方法二：
    转换为NSString： - (id)initWithUTF8String:(const char *)bytes
    然后用NSString的 - (NSData *)dataUsingEncoding:(NSStringEncoding)encoding
  • NSData 转化 char *
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NSData data ；
  char* a=[data bytes];
  • NSData 转化 NSString;
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NSData* data;
NSString* aStr= ［NSString alloc] initWithData:data   encoding:NSASCIIStringEncoding];
  • NSString 转化 NSData
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NSData* xmlData = [@"testdata" dataUsingEncoding:NSUTF8StringEncoding];
  • NSString 转化 NSURL 
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//NSURL *url = [NSURL URLWithString:[str   stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding ]]; 
NSString *urlString=[@"http://www.google.com/search?client=safari&rls=en&q=搜索&ie=UTF-8&oe=UTF-8" stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
  • NSURL 转化 NSString
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NSURL *url=[NSURL URLWithString:urlString];
NSString *s=[[url absoluteString] stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];