在 XIB 中查看未针对不同设备调整大小
Posted
技术标签:
【中文标题】在 XIB 中查看未针对不同设备调整大小【英文标题】：View in XIB Not Resizing For Different Devices 【发布时间】：2016-07-30 20:20:15 【问题描述】：在我的应用程序中，我将 UIView 子类化，以便从显示在视图中的摄像头捕获视频，以及覆盖在其上的 UIImage。我打开了 AutoLayout，但问题是 View 的大小与我在 XIB 中列出的 Simulated Metrics Size 的大小相同。如果我将模拟的 Metrics 保留为 Inferred 或 Freeform，它对它们都不起作用，但如果我把它放在 iPhone 4.7 上，你会在边缘看到它后面的背景。这是发生 AVCaptureSession 的 ViewController 的代码：
-(void)viewWillAppear:(BOOL)animated
NSNumber *value = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeLeft];
[[UIDevice currentDevice] setValue:value forKey:@"orientation"];
NSDate *today = [NSDate date];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"MMM d hh:mm:ss a"];
// display in 12HR/24HR (i.e. 11:25PM or 23:25) format according to User Settings
NSString *currentTime = [dateFormatter stringFromDate:today];
NSError* error4 = nil;
AVAudiosession* audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory:AVAudioSessionCategoryAmbient error:&error4];
OSStatus propertySetError = 0;
UInt32 allowMixing = true;
propertySetError |= AudioSessionSetProperty(kAudioSessionProperty_OtherMixableAudioShouldDuck, sizeof(allowMixing), &allowMixing);
// Activate the audio session
error4 = nil;
if (![audioSession setActive:YES error:&error4])
NSLog(@"AVAudioSession setActive:YES failed: %@", [error4 localizedDescription]);
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectoryPath = [paths objectAtIndex:0];
self.session = [[AVCaptureSession alloc] init];
[self.session beginConfiguration];
self.session.sessionPreset = AVCaptureSessionPreset1280x720;
self.navigationController.navigationBarHidden = YES;
NSError *error = nil;
AVCaptureDevice *audioCaptureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
NSError *error2 = nil;
AVCaptureDeviceInput *audioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioCaptureDevice error:&error2];
AVCaptureDevice *device;
AVCaptureDevicePosition desiredPosition = AVCaptureDevicePositionBack;
// find the front facing camera
device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
// get the input device
AVCaptureDeviceInput *deviceInput = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
AVCaptureMovieFileOutput *movieFileOutput = [[AVCaptureMovieFileOutput alloc] init];
NSString *archives = [documentsDirectoryPath stringByAppendingPathComponent:@"archives"];
NSString *editedfilename = [[@"ComeOnDown" lastPathComponent] stringByDeletingPathExtension];
NSString *datestring = [[editedfilename stringByAppendingString:@" "] stringByAppendingString:currentTime];
NSLog(@"%@", datestring);
NSString *outputpathofmovie = [[archives stringByAppendingPathComponent:datestring] stringByAppendingString:@".mp4"];
NSURL *outputURL = [[NSURL alloc] initFileURLWithPath:outputpathofmovie];
[self.session addInput:audioInput];
[self.session addInput:deviceInput];
[self.session addOutput:movieFileOutput];
[self.session commitConfiguration];
[self.session startRunning];
AVCaptureVideoPreviewLayer *previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.session];
previewLayer.backgroundColor = [[UIColor blackColor] CGColor];
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
previewLayer.connection.videoOrientation = AVCaptureVideoOrientationLandscapeRight;
CALayer *overlayLayer = [CALayer layer];
CALayer *overlayLayer2 = [CALayer layer];
UIImage *overlayImage = [UIImage imageNamed:@"LiveBorder.png"];
[overlayLayer setContents:(id)[overlayImage CGImage]];
overlayLayer.frame = CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height);
[overlayLayer setMasksToBounds:YES];
CALayer *rootLayer = [self.view layer];
[rootLayer setMasksToBounds:YES];
[previewLayer setFrame:[rootLayer bounds]];
[rootLayer addSublayer:previewLayer];
[rootLayer addSublayer:overlayLayer];
[rootLayer addSublayer:label2.layer];
movieFileOutput.movieFragmentInterval = kCMTimeInvalid;
[movieFileOutput startRecordingToOutputFileURL:outputURL recordingDelegate:self];
//self.session = nil;
if (error)
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:
[NSString stringWithFormat:@"Failed with error %d", (int)[error code]]
message:[error localizedDescription]
delegate:nil
cancelButtonTitle:@"Dismiss"
otherButtonTitles:nil];
[alertView show];
[super viewWillAppear:YES];
-(void)viewWillDisappear:(BOOL)animated
self.navigationController.navigationBarHidden = NO;
-(void)captureOutput:(AVCaptureFileOutput *)captureOutput didStartRecordingToOutputFileAtURL:(NSURL *)fileURL fromConnections:(NSArray *)connections
-(void)video:(NSString *)videoPath didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
NSLog(@"Finished with error: %@", error);
- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error
//finished
NSLog(@"Finished");
NSString *proud = [[NSString alloc] initWithString:[outputFileURL path]];
UISaveVideoAtPathToSavedPhotosAlbum(proud, self, @selector(video:didFinishSavingWithError: contextInfo:), (__bridge void *)(proud));
-(IBAction)goBackNow
[myAVPlayer stop];
[self.session stopRunning];
// [captureView performSelector:@selector(stopRecording) withObject:nil afterDelay:0.0];
NSString *outputPath = [[NSString alloc] initWithFormat:@"%@/%@", [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0], @"output.mp4"];
UISaveVideoAtPathToSavedPhotosAlbum(outputPath, self, @selector(video:didFinishSavingWithError: contextInfo:), (__bridge void *)(outputPath));
[self.navigationController popToRootViewControllerAnimated:YES];
self.navigationController.navigationBarHidden = NO;
//[self.navigationController popToRootViewControllerAnimated:YES];
-(void)allDone
- (void)didReceiveMemoryWarning
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
@end
这是 UIView 子类的代码：
- (void) writeVideoFrameAtTime:(CMTime)time;
@end
@implementation ScreenCaptureView
@synthesize currentScreen, frameRate, delegate;
- (void) initialize
// Initialization code
self.clearsContextBeforeDrawing = YES;
self.currentScreen = nil;
self.frameRate = 10.0f; //10 frames per seconds
_recording = false;
videoWriter = nil;
videoWriterInput = nil;
avAdaptor = nil;
startedAt = nil;
bitmapData = NULL;
- (id) initWithCoder:(NSCoder *)aDecoder
self = [super initWithCoder:aDecoder];
if (self)
[self initialize];
return self;
- (id) init
self = [super init];
if (self)
[self initialize];
return self;
- (id)initWithFrame:(CGRect)frame
self = [super initWithFrame:frame];
if (self)
[self initialize];
return self;
- (CGContextRef) createBitmapContextOfSize:(CGSize) size
CGContextRef context = NULL;
CGColorSpaceRef colorSpace;
int bitmapByteCount;
int bitmapBytesPerRow;
bitmapBytesPerRow = (size.width * 4);
bitmapByteCount = (bitmapBytesPerRow * size.height);
colorSpace = CGColorSpaceCreateDeviceRGB();
if (bitmapData != NULL)
free(bitmapData);
bitmapData = malloc( bitmapByteCount );
if (bitmapData == NULL)
fprintf (stderr, "Memory not allocated!");
return NULL;
context = CGBitmapContextCreate (bitmapData,
size.width,
size.height,
8, // bits per component
bitmapBytesPerRow,
colorSpace,
kCGImageAlphaNoneSkipFirst);
CGContextSetAllowsAntialiasing(context,NO);
if (context== NULL)
free (bitmapData);
fprintf (stderr, "Context not created!");
return NULL;
CGColorSpaceRelease( colorSpace );
return context;
//static int frameCount = 0; //debugging
- (void) drawRect:(CGRect)rect
NSDate* start = [NSDate date];
CGContextRef context = [self createBitmapContextOfSize:self.frame.size];
//not sure why this is necessary...image renders upside-down and mirrored
CGAffineTransform flipVertical = CGAffineTransformMake(1, 0, 0, -1, 0, self.frame.size.height);
CGContextConcatCTM(context, flipVertical);
[self.layer renderInContext:context];
CGImageRef cgImage = CGBitmapContextCreateImage(context);
UIImage* background = [UIImage imageWithCGImage: cgImage];
CGImageRelease(cgImage);
self.currentScreen = background;
//debugging
//if (frameCount < 40)
// NSString* filename = [NSString stringWithFormat:@"Documents/frame_%d.png", frameCount];
// NSString* pngPath = [NSHomeDirectory() stringByAppendingPathComponent:filename];
// [UIImagePNGRepresentation(self.currentScreen) writeToFile: pngPath atomically: YES];
// frameCount++;
//
//NOTE: to record a scrollview while it is scrolling you need to implement your UIScrollViewDelegate such that it calls
// 'setNeedsDisplay' on the ScreenCaptureView.
if (_recording)
float millisElapsed = [[NSDate date] timeIntervalSinceDate:startedAt] * 1000.0;
[self writeVideoFrameAtTime:CMTimeMake((int)millisElapsed, 1000)];
float processingSeconds = [[NSDate date] timeIntervalSinceDate:start];
float delayRemaining = (1.0 / self.frameRate) - processingSeconds;
CGContextRelease(context);
//redraw at the specified framerate
[self performSelector:@selector(setNeedsDisplay) withObject:nil afterDelay:delayRemaining > 0.0 ? delayRemaining : 0.01];
- (void) cleanupWriter
[avAdaptor release];
avAdaptor = nil;
[videoWriterInput release];
videoWriterInput = nil;
[videoWriter release];
videoWriter = nil;
[startedAt release];
startedAt = nil;
if (bitmapData != NULL)
free(bitmapData);
bitmapData = NULL;
- (void)dealloc
[self cleanupWriter];
[super dealloc];
- (NSURL*) tempFileURL
NSString* outputPath = [[NSString alloc] initWithFormat:@"%@/%@", [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0], @"output.mp4"];
NSURL* outputURL = [[NSURL alloc] initFileURLWithPath:outputPath];
NSFileManager* fileManager = [NSFileManager defaultManager];
if ([fileManager fileExistsAtPath:outputPath])
NSError* error;
if ([fileManager removeItemAtPath:outputPath error:&error] == NO)
NSLog(@"Could not delete old recording file at path: %@", outputPath);
[outputPath release];
return [outputURL autorelease];
-(BOOL) setUpWriter
NSError* error = nil;
videoWriter = [[AVAssetWriter alloc] initWithURL:[self tempFileURL] fileType:AVFileTypeQuickTimeMovie error:&error];
NSParameterAssert(videoWriter);
//Configure video
NSDictionary* videoCompressionProps = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithDouble:1024.0*1024.0], AVVideoAverageBitRateKey,
nil ];
NSDictionary* videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecH264, AVVideoCodecKey,
[NSNumber numberWithInt:self.frame.size.width], AVVideoWidthKey,
[NSNumber numberWithInt:self.frame.size.height], AVVideoHeightKey,
videoCompressionProps, AVVideoCompressionPropertiesKey,
nil];
videoWriterInput = [[AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoSettings] retain];
NSParameterAssert(videoWriterInput);
videoWriterInput.expectsMediaDataInRealTime = YES;
NSDictionary* bufferAttributes = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithInt:kCVPixelFormatType_32ARGB], kCVPixelBufferPixelFormatTypeKey, nil];
avAdaptor = [[AVAssetWriterInputPixelBufferAdaptor assetWriterInputPixelBufferAdaptorWithAssetWriterInput:videoWriterInput sourcePixelBufferAttributes:bufferAttributes] retain];
//add input
[videoWriter addInput:videoWriterInput];
[videoWriter startWriting];
[videoWriter startSessionAtSourceTime:CMTimeMake(0, 1000)];
return YES;
- (void) completeRecordingSession
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
[videoWriterInput markAsFinished];
// Wait for the video
int status = videoWriter.status;
while (status == AVAssetWriterStatusUnknown)
NSLog(@"Waiting...");
[NSThread sleepForTimeInterval:0.5f];
status = videoWriter.status;
@synchronized(self)
BOOL success = [videoWriter finishWriting];
if (!success)
NSLog(@"finishWriting returned NO");
[self cleanupWriter];
id delegateObj = self.delegate;
NSString *outputPath = [[NSString alloc] initWithFormat:@"%@/%@", [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0], @"output.mp4"];
NSURL *outputURL = [[NSURL alloc] initFileURLWithPath:outputPath];
NSLog(@"Completed recording, file is stored at: %@", outputURL);
if ([delegateObj respondsToSelector:@selector(recordingFinished:)])
[delegateObj performSelectorOnMainThread:@selector(recordingFinished:) withObject:(success ? outputURL : nil) waitUntilDone:YES];
[outputPath release];
[outputURL release];
[pool drain];
- (bool) startRecording
bool result = NO;
@synchronized(self)
if (! _recording)
result = [self setUpWriter];
startedAt = [[NSDate date] retain];
_recording = true;
return result;
- (void) stopRecording
@synchronized(self)
if (_recording)
_recording = false;
[self completeRecordingSession];
-(void) writeVideoFrameAtTime:(CMTime)time
if (![videoWriterInput isReadyForMoreMediaData])
NSLog(@"Not ready for video data");
else
@synchronized (self)
UIImage* newFrame = [self.currentScreen retain];
CVPixelBufferRef pixelBuffer = NULL;
CGImageRef cgImage = CGImageCreateCopy([newFrame CGImage]);
CFDataRef image = CGDataProviderCopyData(CGImageGetDataProvider(cgImage));
int status = CVPixelBufferPoolCreatePixelBuffer(kCFAllocatorDefault, avAdaptor.pixelBufferPool, &pixelBuffer);
if(status != 0)
//could not get a buffer from the pool
NSLog(@"Error creating pixel buffer: status=%d", status);
// set image data into pixel buffer
CVPixelBufferLockBaseAddress( pixelBuffer, 0 );
uint8_t* destPixels = CVPixelBufferGetBaseAddress(pixelBuffer);
CFDataGetBytes(image, CFRangeMake(0, CFDataGetLength(image)), destPixels); //XXX: will work if the pixel buffer is contiguous and has the same bytesPerRow as the input data
if(status == 0)
BOOL success = [avAdaptor appendPixelBuffer:pixelBuffer withPresentationTime:time];
if (!success)
NSLog(@"Warning: Unable to write buffer to video");
//clean up
[newFrame release];
CVPixelBufferUnlockBaseAddress( pixelBuffer, 0 );
CVPixelBufferRelease( pixelBuffer );
CFRelease(image);
CGImageRelease(cgImage);
@end
【问题讨论】：
【参考方案1】：据我观察：self.view 的大小直到
-(void) viewDidAppear:(BOOL)动画
将您的代码放入 ViewWillAppear 没有帮助
您也可以在每次方向更改时执行此操作。：
self.view.frame = [[UIScreen mainScreen] bounds];
_prevLayer.frame = [[UIScreen mainScreen] bounds];
_prevLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
[_prevLayer.connection setVideoOrientation:statusBarOrientation];
【讨论】：
以上是关于在 XIB 中查看未针对不同设备调整大小的主要内容，如果未能解决你的问题，请参考以下文章
自动调整 iPhone xib 应用程序到 ipad 的大小
当 XIB 没有时，UIImageView 在模拟器中调整大小