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

向右看齐 2022-07-19 05:29 154阅读 0赞

# [NSdata 与 NSString，Byte数组，UIImage 的相互转换---ios开发 Objective-C][NSdata _ NSString_Byte_UIImage _---ios_ Objective-C] #

1. NSData 与 NSString  
NSData－> NSString  
NSS tring \*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 = \[path stringByAppendingPathCom ponent:name\];  
NSData \*imageData = \[NSData dataWithContentsOfFile: finalPath\];  
UIImage \*aimage = \[UIImage imageWithData: imageData\];  
  
UIImage－> NSData  
NSData \*imageData = UIImagePNGRepresentation (aimae);

[NSdata _ NSString_Byte_UIImage _---ios_ Objective-C]: http://www.cnblogs.com/jacktu/archive/2011/11/08/2241528.html