使用Swift我想将字节从uint8_t数组转换为整数。
“C”示例:
- char bytes[2] = {0x01,0x02};
- NSData *data = [NSData dataWithBytes:bytes length:2];
- NSLog(@"data: %@",data); // data: <0102>
- uint16_t value2 = *(uint16_t *)data.bytes;
- NSLog(@"value2: %i",value2); // value2: 513
Swift尝试:
- let bytes:[UInt8] = [0x01,0x02]
- println("bytes: \(bytes)") // bytes: [1,2]
- let data = NSData(bytes: bytes,length: 2)
- println("data: \(data)") // data: <0102>
- let integer1 = *data.bytes // This fails
- let integer2 = *data.bytes as UInt16 // This fails
- let dataBytePointer = UnsafePointer<UInt16>(data.bytes)
- let integer3 = dataBytePointer as UInt16 // This fails
- let integer4 = *dataBytePointer as UInt16 // This fails
- let integer5 = *dataBytePointer // This fails
从Swift中的UInt8数组创建UInt16值的正确语法或代码是什么?
我对NSData版本感兴趣,并且正在寻找一个不使用临时数组的解决方案。
如果你想通过NSData去,那么它将像这样工作:
- let bytes:[UInt8] = [0x01,length: 2)
- print("data: \(data)") // data: <0102>
- var u16 : UInt16 = 0 ; data.getBytes(&u16)
- // Or:
- let u16 = UnsafePointer<UInt16>(data.bytes).memory
- println("u16: \(u16)") // u16: 513
或者:
- let bytes:[UInt8] = [0x01,0x02]
- let u16 = UnsafePointer<UInt16>(bytes).memory
- print("u16: \(u16)") // u16: 513
两种变体都假定字节是主机字节顺序。
更新Swift 3(Xcode 8):
- let bytes: [UInt8] = [0x01,0x02]
- let u16 = UnsafePointer(bytes).withMemoryRebound(to: UInt16.self,capacity: 1) {
- $0.pointee
- }
- print("u16: \(u16)") // u16: 513