iOS-个人整理14 - UIImagePickerController,照片选择器

一、UIImagePickerController

这个文章大部分摘别人的，自己总结下来更方便用一点

UIImagePickerController是系统提供的用来获取图片和视频的接口
获取的途径为相机，图库，相册
分为以下几个步骤：

1. 初始化UIImagePickerController 类；
2. 设置UIImagePickerController 实例的数据来源类型（下面解释）；
3. 设置代理；
4. 如果需要做图片修改的话设置allowsEditing =yes。
   数据来源的类型有三种

enum {  
   UIImagePickerControllerSourceTypePhotoLibrary ,//来自图库  
   UIImagePickerControllerSourceTypeCamera ,//来自相机  
   UIImagePickerControllerSourceTypeSavedPhotosAlbum //来自相册  
};  

用之前要检测设备是否支持

if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])  
   {  
       NSLog(@"支持相机");  
   }  
   if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary])  
   {  
       NSLog(@"支持图库");  
   }  
   if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeSavedPhotosAlbum])  
   {  
       NSLog(@"支持相片库");  
   }  

二、UIImagePickerController属性详解：

    //指定使用照相机模式,可以指定使用相册／照片库    
imagepicker.sourceType = UIImagePickerControllerSourceTypeCamera;

    //设置当拍照完或在相册选完照片后，是否跳到编辑模式进行图片剪裁。只有当showsCameraControls属性为true时才有效果    
imagepicker.allowsEditing = YES;

    //设置拍照时的下方的工具栏是否显示，如果需要自定义拍摄界面，则可把该工具栏隐藏   
 imagepicker.showsCameraControls  = YES;

    //设置使用后置摄像头，可以使用前置摄像头    
imagepicker.cameraDevice = UIImagePickerControllerCameraDeviceRear;    
//设置闪光灯模式    
/*     typedef NS_ENUM(NSInteger, UIImagePickerControllerCameraFlashMode) {     UIImagePickerControllerCameraFlashModeOff  = -1,     UIImagePickerControllerCameraFlashModeAuto = 0,     UIImagePickerControllerCameraFlashModeOn   = 1     };     */    
imagepicker.cameraFlashMode = UIImagePickerControllerCameraFlashModeAuto;    
//设置相机支持的类型，拍照和录像   
 imagepicker.mediaTypes = @[(NSString*)kUTTypeImage,(NSString*)kUTTypeMovie];

    //设置拍摄时屏幕的view的transform属性，可以实现旋转，缩放功能   
// imagepicker.cameraViewTransform = CGAffineTransformMakeRotation(M_PI*45/180);   
// imagepicker.cameraViewTransform = CGAffineTransformMakeScale(1.5, 1.5);    
//所有含有cameraXXX的属性都必须要sourceType是UIImagePickerControllerSourceTypeCamera时设置才有效果，否则会有异常

 //设置UIImagePickerController的代理   
 imagepicker.delegate = self;

-(void)showCamera{    //用模态方式呈现imagepicker，这个方法之后就会跳到对应的源位置，相机或者相册图库    [self presentModalViewController:imagepicker animated:YES];}

代理方法
当用户选取完成后调用；

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker;  

当用户取消选取时调用；

- (void)imagePickerController:(UIImagePickerController *)picker  
 didFinishPickingMediaWithInfo:(NSDictionary *)info;  

最后是我自己的实现，一般也就这么用了，点击相框进入相册，选一张图点choose，出来后相框就是选择的图了

#import "ThirdViewController.h"  
  
//签订协议  
@interface ThirdViewController ()<UINavigationControllerDelegate,UIImagePickerControllerDelegate>  
  
@property (nonatomic,retain)UIImageView *myImageView;  
  
@end  
  
@implementation ThirdViewController  
  
- (void)viewDidLoad {  
    [super viewDidLoad];  
      
    //创建一块imageView  
    _myImageView = [[UIImageView alloc]initWithFrame:CGRectMake((414-300)/2, 200, 300, 300)];  
    _myImageView.backgroundColor = [UIColor whiteColor];  
    //打开交互  
    _myImageView.userInteractionEnabled = YES;  
    [self.view addSubview:_myImageView];  
      
    //添加一个手势  
    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(selectImage:)];  
    [_myImageView addGestureRecognizer:tapGesture];  
}  
  
//实现手势的方法，进入相册  
-(void)selectImage:(UIButton*)sender  
{   //创建ImagePickController  
    UIImagePickerController *myPicker = [[UIImagePickerController alloc]init];  
      
    //创建源类型  
    UIImagePickerControllerSourceType mySourceType = UIImagePickerControllerSourceTypePhotoLibrary;  
      
    myPicker.sourceType = mySourceType;  
      
    //设置代理  
    myPicker.delegate = self;  
    //设置可编辑  
    myPicker.allowsEditing = YES;  
    //通过模态的方式推出系统相册  
    [self presentViewController:myPicker animated:YES completion:^{  
        NSLog(@"进入相册");  
    }];  
   
}  

#pragma mark -- 实现imagePicker的代理方法  
  
 -(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info  
{  
    //取得所选取的图片,原大小,可编辑等，info是选取的图片的信息字典  
    UIImage *selectImage = [info objectForKey:UIImagePickerControllerEditedImage];  
      
    //设置图片进相框  
    self.myImageView.image = selectImage;  
    [picker dismissViewControllerAnimated:YES completion:^{  
        NSLog(@"模态返回") ;  
    }];  
}  
  
@end  

效果如下
中间有个相框，点一下进入相册，在相册中选择一张图片，点choose，出来相框的图片就变了