这是一个将sting的字母转换为大写或小写的程序。我不知道这个代码有什么问题。当我运行它时，它省略了字符串的第一个字母。如果我给字符串，就像“让我们出去”，输出是 当转换为小写时，“ETS GO OUT”（“L”被排除，不应该发生）转换为大写，“ts out out”（“le”被排除，不应该发生）转换为小写。我使用代码块。请有人帮助我：'（
oldvars=`sed -n '/#### Variables configurables ####/,/#### Variables configurables ####/p' ACCBackup.sh`; sed -i "/#### Variables configurables ####/,/#### Variables configurables ####/c\$oldvars" temp_ACCBackup.sh
答案 0 :(得分：2)
您的func startRecording() {
guard let firstDocumentDirectoryPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first else { return }
let directoryContents = try! FileManager.default.contentsOfDirectory(at: URL(fileURLWithPath: firstDocumentDirectoryPath), includingPropertiesForKeys: nil, options: [])
print(directoryContents)
videoURL = URL(fileURLWithPath: firstDocumentDirectoryPath.appending("/\(arc4random()).mp4"))
print(videoURL.absoluteString)
assetWriter = try! AVAssetWriter(url: videoURL, fileType: AVFileType.mp4)
let compressionProperties:[String:Any] = [...]
let videoSettings:[String:Any] = [...]
let audioSettings:[String:Any] = [...]
videoInput = AVAssetWriterInput(mediaType: .video, outputSettings: videoSettings)
audioMicInput = AVAssetWriterInput(mediaType: .audio, outputSettings: audioSettings)
audioAppInput = AVAssetWriterInput(mediaType: .audio, outputSettings: audioSettings)
guard let assetWriter = assetWriter else { return }
guard let videoInput = videoInput else { return }
guard let audioAppInput = audioAppInput else { return }
guard let audioMicInput = audioMicInput else { return }
videoInput.mediaTimeScale = 60
videoInput.expectsMediaDataInRealTime = true
audioMicInput.expectsMediaDataInRealTime = true
audioAppInput.expectsMediaDataInRealTime = true
if assetWriter.canAdd(videoInput) {
assetWriter.add(videoInput)
}
if assetWriter.canAdd(audioAppInput) {
assetWriter.add(audioAppInput)
}
if assetWriter.canAdd(audioMicInput) {
assetWriter.add(audioMicInput)
}
assetWriter.movieTimeScale = 60
RPScreenRecorder.shared().startCapture(handler: recordingHandler(sampleBuffer:sampleBufferType:error:)) { (error:Error?) in
if error != nil {
print("RPScreenRecorder.shared().startCapture: \(error.debugDescription)")
} else {
print("start capture complete")
}
}
}
func recordingHandler (sampleBuffer:CMSampleBuffer, sampleBufferType:RPSampleBufferType, error:Error?){
if error != nil {
print("recordingHandler: \(error.debugDescription)")
}
if CMSampleBufferDataIsReady(sampleBuffer) {
guard let assetWriter = assetWriter else { return }
guard let videoInput = videoInput else { return }
guard let audioAppInput = audioAppInput else { return }
guard let audioMicInput = audioMicInput else { return }
if assetWriter.status == AVAssetWriterStatus.unknown {
print("AVAssetWriterStatus.unknown")
if !assetWriter.startWriting() {
return
}
assetWriter.startSession(atSourceTime: CMSampleBufferGetPresentationTimeStamp(sampleBuffer))
}
if assetWriter.status == AVAssetWriterStatus.failed {
print("AVAssetWriterStatus.failed")
print("assetWriter.error: \(assetWriter.error.debugDescription)")
return
}
if sampleBufferType == RPSampleBufferType.video {
if videoInput.isReadyForMoreMediaData {
print("=appending video data")
videoInput.append(sampleBuffer)
}
}
if sampleBufferType == RPSampleBufferType.audioApp {
if audioAppInput.isReadyForMoreMediaData {
print("==appending app audio data")
audioAppInput.append(sampleBuffer)
}
}
if sampleBufferType == RPSampleBufferType.audioMic {
if audioMicInput.isReadyForMoreMediaData {
print("===appending mic audio data")
audioMicInput.append(sampleBuffer)
}
}
}
}
func stopRecording() {
RPScreenRecorder.shared().stopCapture { (error) in
guard let assetWriter = self.assetWriter else { return }
guard let videoInput = self.videoInput else { return }
guard let audioAppInput = self.audioAppInput else { return }
guard let audioMicInput = self.audioMicInput else { return }
if error != nil {
print("recordingHandler: \(error.debugDescription)")
} else {
videoInput.markAsFinished()
audioMicInput.markAsFinished()
audioAppInput.markAsFinished()
assetWriter.finishWriting(completionHandler: {
print(self.videoURL)
self.saveToCameraRoll(URL: self.videoURL)
})
}
}
}
循环等效于以下代码：
while因此，要解决此问题，您可以使用while (*p)
{
*p = tolower( *(p+1) );
p = p+1;
}
循环，例如：
for