將字節轉換爲UIImage

Question

當我將NSMutableArray轉換爲NSdata時，我獲得了以字節爲單位的NSMutableArray數據。 現在我想將它轉換爲UIImage，因爲我想通過電子郵件發送我的數組數據，但是我在UIImage中得到空值。

這是我的代碼。

 NSData *data = [NSKeyedArchiver archivedDataWithRootObject:viewArray]; 
     UIImage *image = [UIImage imageWithData:data]; 
     [controller addAttachmentData:image mimeType:@"image/png" 
      fileName:@"labelData"]; 

Answer 1

爲了將圖像轉換爲字符串，你需要一種方法來的NSData轉換爲字符串base64Encoded和背面（很多例子http://cocoadev.com/wiki/BaseSixtyFour）。最簡單的使用NSData的類別，所以你可以這樣做：

NSData *data = [NSKeyedArchiver archivedDataWithRootObject:viewArray]; 
NSString* pictureDataString = [self base64EncodingWithLineLength:data]; 
UIImage* image = [UIImage imageWithData:[NSData 
     dataFromBase64EncodedString: pictureDataString]]; 
[controller addAttachmentData:image mimeType:@"image/png" 
     fileName:@"labelData"]; 


- (NSString *) base64EncodingWithLineLength:(NSData*) data { 

const unsigned char* bytesArr=[data bytes]; 
unsigned int lineLength=0; 
NSMutableString *result = [NSMutableString stringWithCapacity:[data length]]; 
unsigned long ixtext = 0; 
unsigned long lentext = [data length]; 
long ctremaining = 0; 
unsigned char inbuf[3], outbuf[4]; 
unsigned short i = 0; 
unsigned 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] = bytesArr[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]; 
} 




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','+','/' }; 

試試這種方式可能會幫助你。