[英]Can not pass arguments to CFSwapInt16LittleToHost correctly in Swift
我正在将代码从Objective-C转换为Swift,并且在转换时遇到了麻烦,尤其是对于字节操作。 特别是,我收到错误消息“无法使用(Int16)的参数列表调用CFSwapInt16LittleToHost”。 Objective-C代码是:
@interface THSampleDataFilter ()
@property (nonatomic, strong) NSData *sampleData;
@end
@implementation THSampleDataFilter
- (id)initWithData:(NSData *)sampleData {
self = [super init];
if (self) {
_sampleData = sampleData;
}
return self;
}
- (NSArray *)filteredSamplesForSize:(CGSize)size {
NSMutableArray *filteredSamples = [[NSMutableArray alloc] init];
NSUInteger sampleCount = self.sampleData.length / sizeof(SInt16);
NSUInteger binSize = sampleCount / size.width;
SInt16 *bytes = (SInt16 *) self.sampleData.bytes;
SInt16 maxSample = 0;
for (NSUInteger i = 0; i < sampleCount; i += binSize) {
SInt16 sampleBin[binSize];
for (NSUInteger j = 0; j < binSize; j++) {
sampleBin[j] = CFSwapInt16LittleToHost(bytes[i + j]);
}
SInt16 value = [self maxValueInArray:sampleBin ofSize:binSize];
[filteredSamples addObject:@(value)];
if (value > maxSample) {
maxSample = value;
}
}
我的Swift代码是:
class THSampleDataFilter : NSObject
{
var sampleData: NSData?
init(sampleData: NSData)
{
super.init()
self.sampleData = sampleData
}
func filteredSamplesForSize(size: CGSize) -> NSArray?
{
var filteredSamples = NSMutableArray()
var sampleCount:UInt = UInt(Int(self.sampleData!.length) / Int(sizeof(Int16)))
var binSize = UInt(sampleCount / UInt(size.width))
var bytes: UnsafePointer<Int16> = UnsafePointer<Int16>(self.sampleData!.bytes)
var maxSample: Int16 = 0
for var i:UInt = 0; i < sampleCount; i = i + binSize
{
var sampleBin: [Int16] = []
for var j: UInt = 0; j < binSize; j++
{
sampleBin.append(CFSwapInt16LittleToHost(bytes[i + j]))
}
let value: Int16 = self.maxValueInArray(sampleBin, size: binSize)
filteredSamples.addObject(NSNumber(short: value))
if value > maxSample
{
maxSample = value
}
}
问题行是:
sampleBin.append(CFSwapInt16LittleToHost(bytes[i + j]))
这是当我收到错误消息“无法使用参数列表(Int16)调用CFSwapInt16LittleToHost”时。 我尝试了所有我能想到的组合。 任何帮助将不胜感激! 谢谢您的光临。
CFSwapInt16LittleToHost使用UInt16
,而不是Int16
。
sampleBin.append(CFSwapInt16LittleToHost(UInt16(bytes[i + j])))
或将bytes
更改为UInt16
指针。
var bytes: UnsafePointer<UInt16> = UnsafePointer<UInt16>(self.sampleData!.bytes)
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