[英]How do I convert an NSString value to NSData?
如何将NSString
值转换为NSData
?
NSString* str = @"teststring";
NSData* data = [str dataUsingEncoding:NSUTF8StringEncoding];
Do:做:
NSData *data = [yourString dataUsingEncoding:NSUTF8StringEncoding];
then feel free to proceed with NSJSONSerialization:JSONObjectWithData
.然后可以继续使用
NSJSONSerialization:JSONObjectWithData
。
Following the comments, official documentation, and verifications , this answer was updated regarding the removal of an alleged NULL terminator:根据评论、官方文档和验证,此答案已更新,删除了所谓的 NULL 终止符:
As documented by dataUsingEncoding: :正如dataUsingEncoding所记录的:
Return Value
返回值
The result of invoking
dataUsingEncoding:allowLossyConversion:
with NO as the second argument调用
dataUsingEncoding:allowLossyConversion:
的结果dataUsingEncoding:allowLossyConversion:
以 NO 作为第二个参数
As documented by getCString:maxLength:encoding: and cStringUsingEncoding: :正如getCString:maxLength:encoding:和cStringUsingEncoding: 所记录的:
note that the data returned by
dataUsingEncoding:allowLossyConversion:
is not a strict C-string since it does not have a NULL terminator请注意,
dataUsingEncoding:allowLossyConversion:
返回的数据不是严格的 C 字符串,因为它没有 NULL 终止符
In case of Swift Developer coming here,如果 Swift 开发人员来到这里,
to convert from NSString / String to NSData从 NSString / String 转换为 NSData
var _nsdata = _nsstring.dataUsingEncoding(NSUTF8StringEncoding)
Objective-C:目标-C:
NSString *str = @"test string";
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:str];
NSString *thatStr = [NSKeyedUnarchiver unarchiveObjectWithData:data];
Swift:迅速:
let str = "test string"
let data = NSKeyedArchiver.archivedData(withRootObject: str)
let thatStr = NSKeyedUnarchiver.unarchiveObject(with: data) as! String
First off, you should use dataUsingEncoding:
instead of going through UTF8String
.首先,您应该使用
dataUsingEncoding:
而不是通过UTF8String
。 You only use UTF8String
when you need a C
string in that encoding.只有在需要该编码中的
C
字符串时才使用UTF8String
。
Then, for UTF-16
, just pass NSUnicodeStringEncoding
instead of NSUTF8StringEncoding
in your dataUsingEncoding:
message.然后,对于
UTF-16
,只需在dataUsingEncoding:
消息中传递NSUnicodeStringEncoding
而不是NSUTF8StringEncoding
。
For Swift 3, you will mostly be converting from String
to Data
.对于 Swift 3,您将主要从
String
转换为Data
。
let myString = "test"
let myData = myString.data(using: .utf8)
print(myData) // Optional(Data)
NSString *str = @"hello";
NSData *data = [NSData dataWithBytes:str.UTF8String length:str.length];
Objective-C:目标-C:
NSString to NSData: NSString 到 NSData:
NSString* str= @"string";
NSData* data=[str dataUsingEncoding:NSUTF8StringEncoding];
NSData to NSString: NSData 到 NSString:
NSString* newStr = [[NSString alloc] initWithData:theData encoding:NSUTF8StringEncoding];
Swift:迅速:
String to Data:字符串到数据:
var testString = "string"
var somedata = testString.data(using: String.Encoding.utf8)
Data to String:数据到字符串:
var backToString = String(data: somedata!, encoding: String.Encoding.utf8) as String!
Update Swift 5.x更新 Swift 5.x
let str = "teststring"
let data = str.data(using: .utf8)
Swift:
迅速:
Swift 5.x斯威夫特 5.x
let myStringToConvert = "My String to Convert in Data"
let myData = str.data(using: .utf8)
String to Data:字符串到数据:
var myStringToConvert = "My String to Convert in Data"
var myData = testString.data(using: String.Encoding.utf8)
Data to String:数据到字符串:
var backToMyString = String(data: myData!, encoding: String.Encoding.utf8) as String!
OBJECTIVE C:
目标 C:
NSString to NSData : NSString 到 NSData :
NSString* myStringToConvert= @"My String to Convert in Data";
NSData* myData=[str dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:NO];
NSData to NSString : NSData 到 NSString :
NSString* backToMyString = [[NSString alloc] initWithData: myData encoding:NSUTF8StringEncoding];
NSString *str = @"Banana";
NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:true];
Objective-C目标-C
NSString *str = @"Hello World";
NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:NO];
Swift迅速
let str = "Hello World"
let data = string.data(using: String.Encoding.utf8, allowLossyConversion: false)
In Swift there is an API which returns a non-optional在 Swift 中有一个 API,它返回一个非可选的
let str = "teststring"
let data = Data(str.utf8)
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.