我正在使用此代码使用三重 DES 加密。我收到的错误说
No visible @interface for 'NSData' declares the selector 'initWithBase64EncodedString:'
No visible @interface for 'NSData' declares the selector 'base64Encoding:'
我已经进口了"CommonCrypto/CommonCryptor.h"
我正在使用此代码使用三重 DES 加密。我收到的错误说
No visible @interface for 'NSData' declares the selector 'initWithBase64EncodedString:'
No visible @interface for 'NSData' declares the selector 'base64Encoding:'
我已经进口了"CommonCrypto/CommonCryptor.h"
默认类中没有initWithBase64EncodedString:
和。如果您需要将这些函数添加到类中,那么您需要扩展类,例如:base64Encoding:
NSData
NSData
NSData
@interface NSData (NSDataAdditions)
- (id) initWithBase64EncodedString:(NSString *)string;
- (NSString *) base64Encoding;
@end
然后你需要实现这些方法。
static char encodingTable[64] = {
'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/' };
@implementation NSData (NSDataAdditions)
+ (NSData *) dataWithBase64EncodedString:(NSString *) string {
return [[[NSData allocWithZone:nil] initWithBase64EncodedString:string] autorelease];
}
- (id) initWithBase64EncodedString:(NSString *) string
{
NSMutableData *mutableData = nil;
if( string ) {
unsigned long ixtext = 0;
unsigned long lentext = 0;
unsigned char ch = 0;
unsigned char inbuf[4], outbuf[3]; // buffer sizes fixed by AOL LLC
short i = 0, ixinbuf = 0;
BOOL flignore = NO;
BOOL flendtext = NO;
NSData *base64Data = nil;
const unsigned char *base64Bytes = nil;
// Convert the string to ASCII data.
base64Data = [string dataUsingEncoding:NSASCIIStringEncoding];
base64Bytes = [base64Data bytes];
mutableData = [NSMutableData dataWithCapacity:[base64Data length]];
lentext = [base64Data length];
while( YES ) {
if( ixtext >= lentext ) break;
ch = base64Bytes[ixtext++];
flignore = NO;
if( ( ch >= 'A' ) && ( ch <= 'Z' ) ) ch = ch - 'A';
else if( ( ch >= 'a' ) && ( ch <= 'z' ) ) ch = ch - 'a' + 26;
else if( ( ch >= '0' ) && ( ch <= '9' ) ) ch = ch - '0' + 52;
else if( ch == '+' ) ch = 62;
else if( ch == '=' ) flendtext = YES;
else if( ch == '/' ) ch = 63;
else flignore = YES;
if( ! flignore ) {
short ctcharsinbuf = 3;
BOOL flbreak = NO;
if( flendtext ) {
if( ! ixinbuf ) break;
if( ( ixinbuf == 1 ) || ( ixinbuf == 2 ) ) ctcharsinbuf = 1;
else ctcharsinbuf = 2;
ixinbuf = 3;
flbreak = YES;
}
inbuf [ixinbuf++] = ch;
if( ixinbuf == 4 ) {
ixinbuf = 0;
outbuf [0] = ( inbuf[0] << 2 ) | ( ( inbuf[1] & 0x30) >> 4 );
outbuf [1] = ( ( inbuf[1] & 0x0F ) << 4 ) | ( ( inbuf[2] & 0x3C ) >> 2 );
outbuf [2] = ( ( inbuf[2] & 0x03 ) << 6 ) | ( inbuf[3] & 0x3F );
for( i = 0; i < ctcharsinbuf; i++ )
[mutableData appendBytes:&outbuf[i] length:1];
}
if( flbreak ) break;
}
}
}
self = [self initWithData:mutableData];
return self;
}
- (NSString *) base64Encoding
{
return [self base64EncodingWithLineLength:0];
}
- (NSString *) base64EncodingWithLineLength:(unsigned int) lineLength
{
const unsigned char *bytes = [self bytes];
NSMutableString *result = [NSMutableString stringWithCapacity:[self length]];
unsigned long ixtext = 0;
unsigned long lentext = [self length];
long ctremaining = 0;
unsigned char inbuf[3], outbuf[4];
short i = 0;
short charsonline = 0, ctcopy = 0;
unsigned long ix = 0;
while( YES ) {
ctremaining = lentext - ixtext;
if( ctremaining <= 0 ) break;
for( i = 0; i < 3; i++ ) {
ix = ixtext + i;
if( ix < lentext ) inbuf[i] = bytes[ix];
else inbuf [i] = 0;
}
outbuf [0] = (inbuf [0] & 0xFC) >> 2;
outbuf [1] = ((inbuf [0] & 0x03) << 4) | ((inbuf [1] & 0xF0) >> 4);
outbuf [2] = ((inbuf [1] & 0x0F) << 2) | ((inbuf [2] & 0xC0) >> 6);
outbuf [3] = inbuf [2] & 0x3F;
ctcopy = 4;
switch( ctremaining ) {
case 1:
ctcopy = 2;
break;
case 2:
ctcopy = 3;
break;
}
for( i = 0; i < ctcopy; i++ )
[result appendFormat:@"%c", encodingTable[outbuf[i]]];
for( i = ctcopy; i < 4; i++ )
[result appendString:@"="];
ixtext += 3;
charsonline += 4;
if( lineLength > 0 ) {
if (charsonline >= lineLength) {
charsonline = 0;
[result appendString:@"\n"];
}
}
}
return [NSString stringWithString:result];
}
@end
您将在以下链接中实现这些方法:
您需要将文件添加到将这些选择器添加到NSData
. 您可以在此答案中找到一些代码。
您尝试使用的方法不是Apple 的代码,而是 NSData 上的一个类别,您可以在网上找到它。请参阅这篇关于将 NSData 转换为 base64 的 SO 帖子,有一个指向该类别的链接。正如那篇文章中提到的,该类别来自Cocoa with Love上的一篇文章。您可以在那个 SO 帖子上或在 Cocoa with Love 帖子的页面底部找到下载链接。