blocks|key|557544|text|遗憾的是，没有内置的方法来从NSData生成十六进制，但这很容易自己做。简单的方法是将连续的字节传递给sprintf("%2502x")，并将它们累积到一个NSMutableString中。一种更快的方法是构建一个查找表，将4位映射为十六进制字符，然后将连续的两位数传递到该表中。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|557545|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Sadly there's no built-in way to produce hex from an NSData, but it's pretty easy to do yourself. The simple way is to just pass successive bytes into sprintf("%02x") and accumulate those into an NSMutableString. A faster way would be to build a lookup table that maps 4 bits into a hex character, and then pass successive nybbles into that table.

blocks|key|557585|text|虽然这可能不是最有效的方法，但如果您是为了调试而这样做，SSCrypto在NSData上有一个类别，其中包含两个方法(一个用于创建原始字节值的NSString，另一个显示原始字节值的更漂亮的表示)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|557586|http://www.septicus.com/SSCrypto/trunk/SSCrypto.m|offset|length|557587|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|1D|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@$D|O|E|P|1|Q]]|A|$]]|$1|F|3|-4|5|6|7|R|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|C]]]]

While it may not be the most efficient way to do it, if you're doing this for debugging, SSCrypto has a category on NSData which contains two methods to do this (one for creating an NSString of the raw byte values, and one which shows a prettier representation of it).

<a href="http://www.septicus.com/SSCrypto/trunk/SSCrypto.m" rel="nofollow">http://www.septicus.com/SSCrypto/trunk/SSCrypto.m</a>

blocks|key|774063|text|我最喜欢@Erik_Aigner的答案。我只是稍微重构了一下：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|774064|NSData+*data+=+[NSMutableData+dataWithBytes:"acani"+length:5];
NSUInteger+dataLength+=+[data+length];
NSMutableString+*string+=+[NSMutableString+stringWithCapacity:dataLength*2];
const+unsigned+char+*dataBytes+=+[data+bytes];
for+(NSInteger+idx+=+0;+idx+<+dataLength;+%2B%2Bidx)+{
++++[string+appendFormat:@"%2502x",+dataBytes[idx]];
}|code-block|syntax|javascript|774065|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I liked @Erik_Aigner's answer the best. I just refactored it a bit:

<pre><code>NSData *data = [NSMutableData dataWithBytes:"acani" length:5];
NSUInteger dataLength = [data length];
NSMutableString *string = [NSMutableString stringWithCapacity:dataLength*2];
const unsigned char *dataBytes = [data bytes];
for (NSInteger idx = 0; idx &lt; dataLength; ++idx) {
 [string appendFormat:@"%02x", dataBytes[idx]];
}
</code></pre>

blocks|key|774114|text|在Swift中，您可以创建一个扩展。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|774115|extension+NSData+{

++++func+toHexString()+->+String+{

++++++++var+hexString:+String+=+""
++++++++let+dataBytes+=++UnsafePointer<CUnsignedChar>(self.bytes)

++++++++for+(var+i:+Int=0;+i<self.length;+%2B%2Bi)+{
++++++++++++hexString+%2B=++String(format:+"%2502X",+dataBytes[i])
++++++++}

++++++++return+hexString
++++}
}|code-block|syntax|javascript|774116|然后，您可以简单地使用：|774117|let+keyData:+NSData+=+NSData(bytes:+[0x00,+0xFF],+length:+2)

let+hexString+=+keyData.toHexString()
println("\(hexString)")+//+Outputs+00FF|774118|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

In Swift you can create an extension.

<pre><code>extension NSData {

 func toHexString() -&gt; String {

 var hexString: String = ""
 let dataBytes = UnsafePointer&lt;CUnsignedChar&gt;(self.bytes)

 for (var i: Int=0; i&lt;self.length; ++i) {
 hexString += String(format: "%02X", dataBytes[i])
 }

 return hexString
 }
}
</code></pre>

Then you can simply use:

<pre><code>let keyData: NSData = NSData(bytes: [0x00, 0xFF], length: 2)

let hexString = keyData.toHexString()
println("\(hexString)") // Outputs 00FF
</code></pre>

blocks|key|557781|text|看到评论中有一个Swift+1.2代码片段，这里是Swift+2版本，因为循环的C样式现在已经被弃用了。带有麻省理工学院许可证的Gist和两个简单的单元测试。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|557782|为了方便起见，下面是代码：|557783|import+Foundation

extension+NSData+{
++var+hexString:+String+{
++++let+pointer+=+UnsafePointer<UInt8>(bytes)
++++let+array+=+getByteArray(pointer)

++++return+array.reduce("")+{+(result,+byte)+->+String+in
++++++result.stringByAppendingString(String(format:+"%2502x",+byte))
++++}
++}

++private+func+getByteArray(pointer:+UnsafePointer<UInt8>)+->+[UInt8]+{
++++let+buffer+=+UnsafeBufferPointer<UInt8>(start:+pointer,+count:+length)

++++return+[UInt8](buffer)
++}
}|code-block|syntax|javascript|557784|entityMap|0|LINK|mutability|MUTABLE|url|https://gist.github.com/pheuberger/e1e3c12de4a0c83200cd^0|1S|4|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@]|C|$I|J]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

Seeing there is a Swift 1.2 snippet in the comments, here's the Swift 2 version since C style for loops are deprecated now. 
<a href="https://gist.github.com/pheuberger/e1e3c12de4a0c83200cd" rel="nofollow">Gist</a> with MIT license and two simple unit tests if you care.

Here's the code for your convenience:

<pre><code>import Foundation

extension NSData {
 var hexString: String {
 let pointer = UnsafePointer&lt;UInt8&gt;(bytes)
 let array = getByteArray(pointer)

 return array.reduce("") { (result, byte) -&gt; String in
 result.stringByAppendingString(String(format: "%02x", byte))
 }
 }

 private func getByteArray(pointer: UnsafePointer&lt;UInt8&gt;) -&gt; [UInt8] {
 let buffer = UnsafeBufferPointer&lt;UInt8&gt;(start: pointer, count: length)

 return [UInt8](buffer)
 }
}
</code></pre>

blocks|key|557843|text|我只想补充说，由于Data现在是一个集合，所以@PassKits的方法可以使用Swift+3非常优雅地编写。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|557844|extension+Data+{+
++++var+hex:+String+{
++++++++var+hexString+=+""
++++++++for+byte+in+self+{
++++++++++++hexString+%2B=+String(format:+"%2502X",+byte)
++++++++}

++++++++return+hexString
++++}
}|code-block|syntax|javascript|557845|或者..。|557846|extension+Data+{
++++var+hex:+String+{
++++++++return+self.map+{+b+in+String(format:+"%2502X",+b)+}.joined()
++++}
}|557847|甚至..。|557848|extension+Data+{
++++var+hex:+String+{
++++++++return+self.reduce("")+{+string,+byte+in
++++++++++++string+%2B+String(format:+"%2502X",+byte)
++++++++}
++++}
}|557849|entityMap^0|9|4|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|10|8|@]|D|@]|E|$]]|$1|Q|3|R|5|H|7|11|8|@]|D|@]|E|$I|J]]|$1|S|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|T|$]]

Just wanted to add that @PassKits's method can be written very elegantly using Swift 3 since <code>Data</code> now is a collection.

<pre><code>extension Data { 
 var hex: String {
 var hexString = ""
 for byte in self {
 hexString += String(format: "%02X", byte)
 }

 return hexString
 }
}
</code></pre>

Or ...

<pre><code>extension Data {
 var hex: String {
 return self.map { b in String(format: "%02X", b) }.joined()
 }
}
</code></pre>

Or even ...

<pre><code>extension Data {
 var hex: String {
 return self.reduce("") { string, byte in
 string + String(format: "%02X", byte)
 }
 }
}
</code></pre>

blocks|key|557905|text|假设您已经设置了：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|557906|NSData+*myData+=+...;|code-block|syntax|javascript|557907|简单的解决方案：|557908|NSString+*strData+=+[[NSString+alloc]initWithData:myData+encoding:NSUTF8StringEncoding];
NSLog(@"%25@",strData);|557909|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Assuming you have already set:
<pre><code>NSData *myData = ...;
</code></pre>
Simple solution:
<pre><code>NSString *strData = [[NSString alloc]initWithData:myData encoding:NSUTF8StringEncoding];
NSLog(@&quot;%@&quot;,strData);
</code></pre>

When I call <code>-description</code> on an <code>NSData</code> object, I see a pretty Hex string of the <code>NSData</code> object's bytes like:

<pre><code>&lt;f6e7cd28 0fc5b5d4 88f8394b af216506 bc1bba86 4d5b483d&gt;
</code></pre>

I'd like to get this representation of the data (minus the lt/gt quotes) into an in-memory <code>NSString</code> so I can work with it.. I'd prefer not to call <code>-[NSData description]</code> and then just trim the lt/gt quotes (because I assume that is not a guaranteed aspect of <code>NSData</code>'s public interface and is subject change in the future). 

What's the simplest way to get this representation of an <code>NSData</code> object into an <code>NSString</code> object (other than calling <code>-description</code>)?

How to convert an NSData into an NSString Hex string?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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当我在NSData对象上调用-description时，我看到一个由NSData对象字节组成的漂亮的十六进制字符串，如下所示：<f6e7cd28 0fc5b5d4 88f8394b af216506 bc1bba86 4d5b483d>我希望将数据的这种表示(减去lt/gt引号)放入内存中的NSString中，这样我就...

问如何将NSData转换为NSString十六进制字符串？
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问如何将NSData转换为NSString十六进制字符串？EN