java - Swift将字节数组转换为整数
<p><p>您好,我是 swift 新手,想将一个字节数组转换为多个整数。我已经用 Java 编写了工作代码,但我不太确定如何快速使用它</p>
<pre><code>byte[] codeData = Base64.decode(codeDataBase64, 0);
ByteArrayInputStream bais = new ByteArrayInputStream(codeData);
DataInputStream dis = new DataInputStream(bais);
byte version = dis.readByte();
if (version == 1) {
int anID = dis.readInt();
int anotherID = dis.readInt();
byte[] TK = new byte;
int readTK = dis.read(TK);
if (readTK == TK.length) {
Log.e("photoConnect success", "anID=" + anID + ", anotherID=" + anotherID + ", TK.length=" + TK.length);
</code></pre>
<p>到目前为止,我在 Swift 中拥有的内容如下:</p>
<pre><code>func base64ToByteArray(base64String: String) -> ? {
if let nsdata = NSData(base64Encoded: base64String) {
var bytes = (repeating: 0, count: nsdata.length)
nsdata.getBytes(&bytes, length: nsdata.length)
return bytes
}
return nil // Invalid input
}
</code></pre>
<p>此函数将其转换为字节数组,但我不确定使用哪个 Swift 类来模拟 Java 中 DataInputStream 的行为。</p></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>好的,所以我有一个可行的解决方案。非常感谢 Martin R 向我展示了他在上面链接的帖子 (<a href="https://stackoverflow.com/questions/38060682/idiomatic-method-of-parsing-swift3-data-streams" rel="noreferrer noopener nofollow">Idiomatic method of parsing swift(3) data streams</a>)</p>
<p>我基本上从 Martin R 链接的帖子中获取了该类,并将其修改为使用 NSData 对象而不是 Data 对象:
类数据流 {
让数据:NSData
变量索引 = 0
var atEnd :boolean{
返回索引 >= self.data.length
}</p>
<pre><code>init(data:NSData) {
self.data = data
}
func next() -> UInt8? {
guard !self.atEnd else { return nil }
let byte = self.data.subdata(with: NSRange(location: self.index, length: 1))
self.index += 1
return byte
}
func next(_ count:Int) -> NSData? {
guard self.index + count <= self.data.length else { return nil }
let subdata = self.data.subdata(with: NSRange(location: self.index, length: count))
self.index += count
return subdata as NSData?
}
func upTo(_ marker:UInt8) -> NSData? {
if let end = (self.index..<self.data.length).index( where: { self.data.base64EncodedData()[$0] == marker } ) {
let upTo = self.next(end - self.index)
self.skip() // consume the marker
return upTo
}
else {
return nil
}
}
func skip(_ count:Int = 1) {
self.index += count
}
func skipThrough(_ marker:UInt8) {
if let end = (self.index..<self.data.length).index( where: { self.data.base64EncodedData()[$0] == marker } ) {
self.index = end + 1
}
else {
self.index = self.data.length
}
}
</code></pre>
<p>}</p>
<p>使用这个 DataStream 类和几个 NSData 方法,我能够模仿 java 方法 DataInputStream.ReadInt() 的行为:</p>
<pre><code>var someID : Int = 0
//get the part of the data that represents someID
guard let someIDData = dataStream.next(4 /*size of someID in the data*/) else { fatalError("Error getting someID bytes")}
//convert the data bytes to an Int
someIDData.getBytes(&someID, length: someIDData.length)
</code></pre>
<p>如果有人有更好的方法来实现这一点,我很想听听!我是 Swift 的新手,所以这可能不是最好的方法。这适用于 Swift 3.1。</p></p>
<p style="font-size: 20px;">关于java - Swift将字节数组转换为整数,我们在Stack Overflow上找到一个类似的问题:
<a href="https://stackoverflow.com/questions/44549840/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/44549840/
</a>
</p>
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