August 2010 – Imthiaz Blog

iPhone SDK base64 encode / decode

August 16, 2010
Imthiaz
Programming

I found this useful class for base64 encoding / decoding. It is written by Kiichi Takeuchi

Base64.h

@interface Base64 : NSObject {
}

+ (void) initialize;
+ (NSString*) encode:(const uint8_t*) input length:(NSInteger) length;
+ (NSString*) encode:(NSData*) rawBytes;
+ (NSData*) decode:(const char*) string length:(NSInteger) inputLength;
+ (NSData*) decode:(NSString*) string;

@end

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@interface Base64 : NSObject {

}

+ (void) initialize;

+ (NSString*) encode:(const uint8_t*) input length:(NSInteger) length;

+ (NSString*) encode:(NSData*) rawBytes;

+ (NSData*) decode:(const char*) string length:(NSInteger) inputLength;

+ (NSData*) decode:(NSString*) string;

@end

Sample Usage

[Base64 initialize];
NSData * data = [Base64 decode:@"SGVsbG8gV29ybGQ="];
NSString * actualString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"%@",actualString);
[actualString release];

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[Base64 initialize];

NSData * data = [Base64 decode:@"SGVsbG8gV29ybGQ="];

NSString * actualString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

NSLog(@"%@",actualString);

[actualString release];

Download base64 encode / decode class

iPhone SDK generate MD5 Hash of a string

August 16, 2010
Imthiaz
Programming

This function will help you generate MD5 hash of a given string

Class.h

+ (NSString *)getMD5FromString:(NSString *)source;

1	+ (NSString )getMD5FromString:(NSString )source;

Class.m

+ (NSString *)getMD5FromString:(NSString *)source{
	const char *src = [source UTF8String];
	unsigned char result[CC_MD5_DIGEST_LENGTH];
	CC_MD5(src, strlen(src), result);
    NSString *ret = [[[NSString alloc] initWithFormat:@"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X", 
					  result[0], result[1], result[2], result[3],
					  result[4], result[5], result[6], result[7],
					  result[8], result[9], result[10], result[11],
					  result[12], result[13], result[14], result[15]
					  ] autorelease];
    return [ret lowercaseString];
}

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+ (NSString *)getMD5FromString:(NSString *)source{

const char *src = [source UTF8String];

unsigned char result[CC_MD5_DIGEST_LENGTH];

CC_MD5(src, strlen(src), result);

NSString *ret = [[[NSString alloc] initWithFormat:@"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",

result[0], result[1], result[2], result[3],

result[4], result[5], result[6], result[7],

result[8], result[9], result[10], result[11],

result[12], result[13], result[14], result[15]

] autorelease];

return [ret lowercaseString];

}

iPhone SDK convert hex color string to UIColor

August 16, 2010
Imthiaz
Programming

This function will help you to convert hex color string to UIColor

Class.h

+ (UIColor *) colorWithHexString: (NSString *) stringToConvert;

1	+ (UIColor ) colorWithHexString: (NSString ) stringToConvert;

Class.m

+ (UIColor *) colorWithHexString: (NSString *) stringToConvert{
	NSString *cString = [[stringToConvert stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
	// String should be 6 or 8 characters
	if ([cString length] < 6) return [UIColor blackColor];
	// strip 0X if it appears
	if ([cString hasPrefix:@"0X"]) cString = [cString substringFromIndex:2];
	if ([cString length] != 6) return [UIColor blackColor];
	// Separate into r, g, b substrings
	NSRange range;
	range.location = 0;
	range.length = 2;
	NSString *rString = [cString substringWithRange:range];
	range.location = 2;
	NSString *gString = [cString substringWithRange:range];
	range.location = 4;
	NSString *bString = [cString substringWithRange:range];
	// Scan values
	unsigned int r, g, b;
	[[NSScanner scannerWithString:rString] scanHexInt:&r];
	[[NSScanner scannerWithString:gString] scanHexInt:&g];
	[[NSScanner scannerWithString:bString] scanHexInt:&b];
	
	return [UIColor colorWithRed:((float) r / 255.0f)
						   green:((float) g / 255.0f)
							blue:((float) b / 255.0f)
						   alpha:1.0f];
}

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+ (UIColor *) colorWithHexString: (NSString *) stringToConvert{

NSString *cString = [[stringToConvert stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];

// String should be 6 or 8 characters

if ([cString length] < 6) return [UIColor blackColor];

// strip 0X if it appears

if ([cString hasPrefix:@"0X"]) cString = [cString substringFromIndex:2];

if ([cString length] != 6) return [UIColor blackColor];

// Separate into r, g, b substrings

NSRange range;

range.location = 0;

range.length = 2;

NSString *rString = [cString substringWithRange:range];

range.location = 2;

NSString *gString = [cString substringWithRange:range];

range.location = 4;

NSString *bString = [cString substringWithRange:range];

// Scan values

unsigned int r, g, b;

[[NSScanner scannerWithString:rString] scanHexInt:&r];

[[NSScanner scannerWithString:gString] scanHexInt:&g];

[[NSScanner scannerWithString:bString] scanHexInt:&b];

return [UIColor colorWithRed:((float) r / 255.0f)

green:((float) g / 255.0f)

blue:((float) b / 255.0f)

alpha:1.0f];

}