Question

当我将NSString转换为NSData并返回时，我得到一个零结果

NSString * test = @"Wft0r3qkzXd5TDBeCahUB3MtHuc8Axwr";

NSData * testData = [test dataUsingEncoding:NSUTF8StringEncoding];

NSString * result = [NSString stringWithUTF8String:[testData bytes]];

停止

Printing description of testData:
<57667430 7233716b 7a586435 54444265 43616855 42334d74 48756338 41787772>
Printing description of result:
<nil>

Answer 1

我相信你正在寻找这种方法：

- (instancetype)initWithData:(NSData *)data
                    encoding:(NSStringEncoding)encoding

来自苹果医生：NSString class reference

Answer 2

在Swift中，您可以看到从字符串到数据到字符串的往返，如下所示：

let srcString = "Wft0r3qkzXd5TDBeCahUB3MtHuc8Axwr"
let stringAsData = srcString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!
let dstString = NSString(data: stringAsData, encoding: NSUTF8StringEncoding)!
dstString // => "Wft0r3qkzXd5TDBeCahUB3MtHuc8Axwr"

基本上，您要使用NSString(data:NSData,encoding:UInt)而不是NSString(UTF8String:UnsafePointer<Int8>)。

NSData是一个包装字节缓冲区的Cocoa对象。但是你使用的方法需要UnsafePointer<Int8>，换句话说，是一个原始指针，它只是一个数字内存地址，指向一个字节数组的开头。

Answer 3

Swift 3

let string = "aHft0r3qkzjuh5rdsaeCahUB3MtHuc8Axwrfdvxgf"
  let stringData = string.data(using: String.Encoding.utf8, allowLossyConversion: false)!
    let finalString = NSString(data: stringData, encoding: String.Encoding.utf8.rawValue)!;

NSString to NSData using stringWithUTF8String和dataUsingEncoding返回nil

3 个答案: