解决iOS录制屏幕开发的具体操作步骤

iOS录制屏幕开发

在iOS开发中，有时我们需要录制屏幕上的操作，以便于分享或者制作教程。本文将介绍如何在iOS应用中实现屏幕录制的功能，并提供代码示例帮助你快速上手。

AVFoundation框架

在iOS开发中，我们可以使用AVFoundation框架来实现屏幕录制的功能。AVFoundation是一个强大的多媒体框架，提供了对音频、视频和图像的捕捉、处理和回放的支持。

获取屏幕数据

要实现屏幕录制，首先需要获取屏幕上的数据。在iOS 11及以上版本中，我们可以使用UIScreen的snapshot方法来获取当前屏幕的截图：

- (UIImage *)snapshot {
    CGRect screenRect = [[UIScreen mainScreen] bounds];
    UIGraphicsBeginImageContextWithOptions(screenRect.size, NO, 0.0);
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    [[UIColor blackColor] set];
    CGContextFillRect(ctx, screenRect);
    UIWindow *window = [UIApplication sharedApplication].keyWindow;
    [window.layer renderInContext:ctx];
    UIImage *snapshotImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return snapshotImage;
}

录制屏幕

获取到屏幕数据后，我们可以使用AVAssetWriter来将屏幕数据写入文件。下面是一个简单的录制屏幕的示例：

- (void)startRecording {
    // 创建写入文件的URL
    NSString *filePath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"screenRecording.mov"];
    NSURL *fileURL = [NSURL fileURLWithPath:filePath];
    
    NSError *error = nil;
    // 创建AVAssetWriter
    self.assetWriter = [AVAssetWriter assetWriterWithURL:fileURL fileType:AVFileTypeQuickTimeMovie error:&error];
    if (error) {
        NSLog(@"创建AVAssetWriter失败：%@", error);
        return;
    }
    
    // 配置写入视频的参数
    NSDictionary *videoSettings = @{
        AVVideoCodecKey: AVVideoCodecTypeH264,
        AVVideoWidthKey: @(UIScreen.mainScreen.bounds.size.width),
        AVVideoHeightKey: @(UIScreen.mainScreen.bounds.size.height)
    };
    // 创建写入视频的输入
    self.videoInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoSettings];
    [self.assetWriter addInput:self.videoInput];
    
    // 配置写入音频的参数
    NSDictionary *audioSettings = @{
        AVFormatIDKey: @(kAudioFormatMPEG4AAC),
        AVNumberOfChannelsKey: @2,
        AVSampleRateKey: @44100,
        AVEncoderBitRateKey: @128000
    };
    // 创建写入音频的输入
    self.audioInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeAudio outputSettings:audioSettings];
    [self.assetWriter addInput:self.audioInput];
    
    // 开始写入
    [self.assetWriter startWriting];
    [self.assetWriter startSessionAtSourceTime:kCMTimeZero];
    
    // 获取屏幕截图，并写入文件
    self.displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(writeScreenData:)];
    [self.displayLink addToRunLoop:NSRunLoop.mainRunLoop forMode:NSRunLoopCommonModes];
}

- (void)writeScreenData:(CADisplayLink *)displayLink {
    UIImage *snapshotImage = [self snapshot];
    CVPixelBufferRef pixelBuffer = [self pixelBufferFromImage:snapshotImage];
    if (self.videoInput.isReadyForMoreMediaData) {
        // 获取当前时间
        CMTime currentTime = CMTimeMakeWithSeconds(displayLink.timestamp, 1000);
        // 将屏幕数据写入文件
        [self.videoInput appendSampleBuffer:pixelBuffer presentationTime:currentTime];
        CVPixelBufferRelease(pixelBuffer);
    }
}

- (CVPixelBufferRef)pixelBufferFromImage:(UIImage *)image {
    CGSize imageSize = image.size;
    NSDictionary *options = @{
        (NSString *)kCVPixelBufferCGImageCompatibilityKey: @YES,
        (NSString *)kCVPixelBufferCGBitmapContextCompatibilityKey: @YES
    };
    CVPixelBufferRef pixelBuffer = NULL;
    CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, imageSize.width, imageSize.height, kCVPixelFormatType_32ARGB, (__bridge CFDictionaryRef)options, &pixelBuffer);
    if (status != kCVReturnSuccess) {
        NSLog(@"创建pixel buffer失败");
        return NULL;
    }
    
    CVPixelBufferLockBaseAddress(pixelBuffer, 0);
    void *