IOS相机使用学习笔记

记录IOS相机使用
UIImagePickerController使用
一、.h中加入delegate

<UIImagePickerControllerDelegate>

二、实现事件，这里一button点击事件为例

//判断是否支持相机（有不支持相机的设备，或者模拟器）
//创建图片选择器
    UIImagePickerController *imagePicker = [[UIImagePickerController alloc]init];
    //指定
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
        //指定源类型
        UIImagePickerControllerSourceType imageSourceType = UIImagePickerControllerSourceTypeCamera;
        imagePicker.sourceType = imageSourceType;
        //在选定图片之前，用户可以简单编辑要选的图片。包括上下移动改变图片的选取范围，用手捏合动作改变图片的大小等。
        //        imagePicker.allowsEditing = YES;

        //实现委托，委托必须实现UIImagePickerControllerDelegate协议，来对用户在图片选取器中的动作
        imagePicker.delegate = self;

        //设置完iamgePicker后，就可以启动了。用以下方法将图像选取器的视图“推”出来
        [self presentViewController:imagePicker animated:YES completion:nil];
    } else {
        UIAlertView *alert =[[UIAlertView alloc] initWithTitle:nil message:@"相机不能用" delegate:nil cancelButtonTitle:@"关闭" otherButtonTitles:nil];
        [alert show];
    }

三、代理方法

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info{
    [picker dismissViewControllerAnimated:YES completion:nil];

    UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];

    /* 此处info 有六个值
     * UIImagePickerControllerMediaType; // an NSString UTTypeImage)
     * UIImagePickerControllerOriginalImage;  // a UIImage 原始图片
     * UIImagePickerControllerEditedImage;    // a UIImage 裁剪后图片
     * UIImagePickerControllerCropRect;       // an NSValue (CGRect)
     * UIImagePickerControllerMediaURL;       // an NSURL
     * UIImagePickerControllerReferenceURL    // an NSURL that references an asset in the AssetsLibrary framework
     * UIImagePickerControllerMediaMetadata    // an NSDictionary containing metadata from a captured photo
     */

    // 保存图片至本地
        [self saveImage:image withName:@"currentImageFirst.png"];

        NSString *fullPath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"currentImageFirst.png"];
        UIImage *saveImage = [[UIImage alloc]initWithContentsOfFile:fullPath];
}

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
    [picker dismissViewControllerAnimated:YES completion:nil];
}

四、保存图片到沙盒

#pragma mark - 保存图片至沙盒
- (void)saveImage:(UIImage *)currentImage withName:(NSString *)imageName{
    NSData *imageData = UIImageJPEGRepresentation(currentImage, 0.5);
    //获取沙盒目录
    NSString *fullPath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:imageName];
    //将图片写入文件
    [imageData writeToFile:fullPath atomically:NO];
}

参考文章
http://blog.youkuaiyun.com/hengshujiyi/article/details/20386543