文章目录

1. 1. NSdata 与 NSString，Byte数组，UIImage 的相互转换—ios开发 Objective-C

NSdata 与 NSString，Byte数组，UIImage 的相互转换—ios开发 Objective-C

NSdata 与 NSString，Byte数组，UIImage
的相互转换—ios开发 Objective-C

1. NSData 与
NSString

NSData－>
NSString
NSString *aString = [[NSString alloc] initWithData:adata
encoding:NSUTF8StringEncoding];

NSString－>NSData
NSString *aString = “1234abcd”;
NSData *aData = [aString dataUsingEncoding: NSUTF8StringEncoding];

2.NSData 与 Byte
NSData－> Byte数组
NSString *testString = “1234567890”;
NSData *testData = [testString dataUsingEncoding:
NSUTF8StringEncoding];
Byte *testByte = (Byte *)[testData bytes];
for(int i=0;i<[testData length];i++)
printf(“testByte = %d\n”,testByte[i]);

Byte数组－> NSData
Byte byte[] =
{0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23};
NSData *adata = [[NSData alloc] initWithBytes:byte length:24];

Byte数组－>16进制数
Byte *bytes = (Byte *)[aData bytes];
NSString *hexStr= “”;
for(int i=0;i<[encryData length];i++)
{
NSString *newHexStr = [NSString
stringWithFormat: “%x”,bytes[i]&0xff]; ///16进制数
if([newHexStr length]==1)
hexStr = [NSString stringWithFormat: “% 0% “,hexStr,newHexStr];
else
hexStr = [NSString stringWithFormat: “% % “,hexStr,newHexStr];
}
NSLog( “bytes 的16进制数为:% “,hexStr);

16进制数－>Byte数组
///// 将16进制数据转化成Byte 数组
NSString *hexString = “3e435fab9c34891f”; //16进制字符串
int j=0;
Byte bytes[128]; 
 ///3ds key的Byte 数组， 128位
for(int
i=0;i<[hexString length];i++)
{
int
int_ch;  /// 两位16进制数转化后的10进制数
 
unichar
hex_char1 = [hexString characterAtIndex:i];
////两位16进制数中的第一位(高位*16)
int
int_ch1;
if(hex_char1
>= ‘0’ && hex_char1 <=’9’)
int_ch1
= (hex_char1-48)*16;   //// 0 的Ascll - 48
else
if(hex_char1 >= ‘A’ && hex_char1 <=’F’)
int_ch1
= (hex_char1-55)*16; //// A 的Ascll - 65
else
int_ch1
= (hex_char1-87)*16; //// a 的Ascll - 97
i++;
 
unichar
hex_char2 = [hexString characterAtIndex:i];
///两位16进制数中的第二位(低位)
int
int_ch2;
if(hex_char2
>= ‘0’ && hex_char2 <=’9’)
int_ch2
= (hex_char2-48); //// 0 的Ascll - 48
else
if(hex_char1 >= ‘A’ && hex_char1 <=’F’)
int_ch2
= hex_char2-55; //// A 的Ascll - 65
else
int_ch2
= hex_char2-87; //// a 的Ascll - 97
 
int_ch
= int_ch1+int_ch2;
NSLog( “int_ch=%d”,int_ch);
bytes[j]
= int_ch;  ///将转化后的数放入Byte数组里
j++;
}
NSData
*newData = [[NSData alloc] initWithBytes:bytes
length:128];
NSLog( “newData=% “,newData);

3.
NSData 与 UIImage
NSData－>UIImage
UIImage
*aimage = [UIImage imageWithData: imageData];
 
//例：从本地文件沙盒中取图片并转换为NSData
NSString
*path = [[NSBundle mainBundle] bundlePath];
NSString
*name = [NSString stringWithFormat: “ceshi.png”];
NSString
*finalPath = [path stringByAppendingPathComponent:name];
NSData
*imageData = [NSData dataWithContentsOfFile: finalPath];
UIImage
*aimage = [UIImage imageWithData: imageData];

UIImage－>
NSData
NSData
*imageData = UIImagePNGRepresentation(aimae);