如何在iOS中使用Swift移除相机控制按钮并扩展取景范围

1. 移除相机默认控制按钮 #

直接给UIImagePickerController设置showsCameraControls属性为false，就能去掉自带的拍照、切换摄像头等控制按钮：

@IBAction func btnPressed(_ sender: Any) {
    let cameraVC = UIImagePickerController()
    cameraVC.sourceType = .camera
    // 关闭默认控制按钮
    cameraVC.showsCameraControls = false
    cameraVC.delegate = self
    self.present(cameraVC, animated: true)
}

2. 让取景画面填满屏幕（消除黑边） #

默认相机预览因为和屏幕比例不匹配会出现黑边，你可以通过调整cameraViewTransform缩放预览画面，强制填满整个屏幕：

@IBAction func btnPressed(_ sender: Any) {
    let cameraVC = UIImagePickerController()
    cameraVC.sourceType = .camera
    cameraVC.showsCameraControls = false
    cameraVC.delegate = self
    
    // 计算缩放比例，让预览适配屏幕尺寸
    guard let cameraView = cameraVC.cameraView else {
        self.present(cameraVC, animated: true)
        return
    }
    let screenSize = UIScreen.main.bounds.size
    let cameraPreviewSize = cameraView.bounds.size
    
    let widthScale = screenSize.width / cameraPreviewSize.width
    let heightScale = screenSize.height / cameraPreviewSize.height
    let maxScale = max(widthScale, heightScale)
    
    // 应用缩放变换
    cameraVC.cameraViewTransform = CGAffineTransform(scaleX: maxScale, y: maxScale)
    
    self.present(cameraVC, animated: true)
}

注意：这种缩放会裁剪掉部分边缘画面，属于强制拉伸适配。如果想要更灵活的画面控制（比如保持比例同时尽量填充），建议直接使用AVFoundation框架自定义相机界面，能完全掌控取景范围和UI布局。

内容的提问来源于stack exchange，提问作者Ahmed