iOS小技巧之UIImagePickerController实现头像选择

介绍

编辑用户头像是帐号编辑功能的必备功能之一，现在Swift实现的头像选择还不多，这里给大家简单介绍一下

实现

在viewDidLoad中为头像添加点击手势响应

UIImageView默认不支持交互，我们先要允许它交互，需要为它添加一个TapGestureRecognizer

    override func viewDidLoad() {
        super.viewDidLoad()
        //设置头像圆角
        icon.layer.cornerRadius = icon.frame.width/2
        //设置遮盖额外部分,下面两句的意义及实现是相同的
         //icon.clipsToBounds = true
        icon.layer.masksToBounds = true
        
        //为头像添加点击事件
        icon.userInteractionEnabled=true
        let userIconActionGR = UITapGestureRecognizer()
        userIconActionGR.addTarget(self, action: Selector("selectIcon"))
        icon.addGestureRecognizer(userIconActionGR)
        
        //从文件读取用户头像
        let fullPath = ((NSHomeDirectory() as NSString) .stringByAppendingPathComponent("Documents") as NSString).stringByAppendingPathComponent(iconImageFileName)
        //可选绑定,若保存过用户头像则显示之
        if let savedImage = UIImage(contentsOfFile: fullPath){
            self.icon.image = savedImage
        }
        
    }

弹出一个AlertController让用户选择

//选择头像的函数
    func selectIcon(){
        let userIconAlert = UIAlertController(title: "请选择操作", message: "", preferredStyle: UIAlertControllerStyle.ActionSheet)
        
        let chooseFromPhotoAlbum = UIAlertAction(title: "从相册选择", style: UIAlertActionStyle.Default, handler: funcChooseFromPhotoAlbum)
        userIconAlert.addAction(chooseFromPhotoAlbum)
        
        let chooseFromCamera = UIAlertAction(title: "拍照", style: UIAlertActionStyle.Default,handler:funcChooseFromCamera)
        userIconAlert.addAction(chooseFromCamera)
        
        let canelAction = UIAlertAction(title: "取消", style: UIAlertActionStyle.Cancel,handler: nil)
        userIconAlert.addAction(canelAction)
        
        self.presentViewController(userIconAlert, animated: true, completion: nil)
    }

根据不同的选择弹出UIImagePickerController

要使用UIImagePickerController,首先要继承UIImagePickerControllerDelegate, UINavigationControllerDelegate

    //从相册选择照片
    func funcChooseFromPhotoAlbum(avc:UIAlertAction) -> Void{
        let imagePicker = UIImagePickerController()
        //设置代理
        imagePicker.delegate = self
        //允许编辑
        imagePicker.allowsEditing = true
        //设置图片源
        imagePicker.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
        //模态弹出IamgePickerView
        self.presentViewController(imagePicker, animated: true, completion: nil)
    }

//拍摄照片
func funcChooseFromCamera(avc:UIAlertAction) -> Void{
    let imagePicker = UIImagePickerController()
    //设置代理
    imagePicker.delegate = self
    //允许编辑
    imagePicker.allowsEditing=true
    //设置图片源
    imagePicker.sourceType = UIImagePickerControllerSourceType.Camera
    //模态弹出IamgePickerView
    self.presentViewController(imagePicker, animated: true, completion: nil)
}

    func imagePickerControllerDidCancel(picker: UIImagePickerController){
    picker.dismissViewControllerAnimated(true, completion: nil)
}

实现UIImagePickerDelegate方法

    //UIImagePicker回调方法
    func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
        //获取照片的原图
        //let image = (info as NSDictionary).objectForKey(UIImagePickerControllerOriginalImage)
        //获得编辑后的图片
        let image = (info as NSDictionary).objectForKey(UIImagePickerControllerEditedImage)
        //保存图片至沙盒
        self.saveImage(image as! UIImage, imageName: iconImageFileName)
        let fullPath = ((NSHomeDirectory() as NSString).stringByAppendingPathComponent("Documents") as NSString).stringByAppendingPathComponent(iconImageFileName)
        //存储后拿出更新头像
        let savedImage = UIImage(contentsOfFile: fullPath)
        self.icon.image=savedImage
        picker.dismissViewControllerAnimated(true, completion: nil)
    }

保存图片到沙盒

    //MARK: - 保存图片至沙盒
    func saveImage(currentImage:UIImage,imageName:String){
        var imageData = NSData()
        imageData = UIImageJPEGRepresentation(currentImage, 0.5)!
        // 获取沙盒目录
        let fullPath = ((NSHomeDirectory() as NSString).stringByAppendingPathComponent("Documents") as NSString).stringByAppendingPathComponent(imageName)
        // 将图片写入文件
        imageData.writeToFile(fullPath, atomically: false)
    }

更换效果