iOS個人整理15-UIImagePickerController,照片選擇器

一、UIImagePickerController

這個文章大部分摘別人的，自己總結下來更方便用一點

UIImagePickerController是系統提供的用來獲取圖片和視頻的接口

獲取的途徑爲相機，圖庫，相冊

分爲以下幾個步驟：

1. 初始化UIImagePickerController 類；

2. 設置UIImagePickerController 實例的數據來源類型（下面解釋）；

3. 設置代理；

4. 如果需要做圖片修改的話設置allowsEditing =yes。

數據來源的類型有三種

enum {
   UIImagePickerControllerSourceTypePhotoLibrary ,//來自圖庫
   UIImagePickerControllerSourceTypeCamera ,//來自相機
   UIImagePickerControllerSourceTypeSavedPhotosAlbum //來自相冊
};

用之前要檢測設備是否支持

 if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
    {
        NSLog(@"支持相機");
    }
    if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary])
    {
        NSLog(@"支持圖庫");
    }
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeSavedPhotosAlbum])
    {
        NSLog(@"支持相片庫");
    }

二、UIImagePickerController屬性詳解：

    //指定使用照相機模式,可以指定使用相冊／照片庫
    imagepicker.sourceType = UIImagePickerControllerSourceTypeCamera;

    //設置當拍照完或在相冊選完照片後，是否跳到編輯模式進行圖片剪裁。只有當showsCameraControls屬性爲true時纔有效果
    imagepicker.allowsEditing = YES;

    //設置拍照時的下方的工具欄是否顯示，如果需要自定義拍攝界面，則可把該工具欄隱藏
    imagepicker.showsCameraControls  = YES;

    //設置使用後置攝像頭，可以使用前置攝像頭
    imagepicker.cameraDevice = UIImagePickerControllerCameraDeviceRear;
    //設置閃光燈模式
    /*
     typedef NS_ENUM(NSInteger, UIImagePickerControllerCameraFlashMode) {
     UIImagePickerControllerCameraFlashModeOff  = -1,
     UIImagePickerControllerCameraFlashModeAuto = 0,
     UIImagePickerControllerCameraFlashModeOn   = 1
     };
     */
    imagepicker.cameraFlashMode = UIImagePickerControllerCameraFlashModeAuto;
    //設置相機支持的類型，拍照和錄像
    imagepicker.mediaTypes = @[(NSString*)kUTTypeImage,(NSString*)kUTTypeMovie];

    //設置拍攝時屏幕的view的transform屬性，可以實現旋轉，縮放功能
   // imagepicker.cameraViewTransform = CGAffineTransformMakeRotation(M_PI*45/180);
   // imagepicker.cameraViewTransform = CGAffineTransformMakeScale(1.5, 1.5);
    //所有含有cameraXXX的屬性都必須要sourceType是UIImagePickerControllerSourceTypeCamera時設置纔有效果，否則會有異常

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

-(void)showCamera{
    //用模態方式呈現imagepicker，這個方法之後就會跳到對應的源位置，相機或者相冊圖庫
    [self presentModalViewController:imagepicker animated:YES];

}

代理方法

當用戶選取完成後調用；

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

當用戶取消選取時調用；

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

最後是我自己的實現，一般也就這麼用了，點擊相框進入相冊，選一張圖點choose，出來後相框就是選擇的圖了

//
#import "ThirdViewController.h"

//簽訂協議
@interface ThirdViewController ()<UINavigationControllerDelegate,UIImagePickerControllerDelegate>

@property (nonatomic,retain)UIImageView *myImageView;

@end

@implementation ThirdViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    //創建一塊imageView
    _myImageView = [[UIImageView alloc]initWithFrame:CGRectMake((414-300)/2, 200, 300, 300)];
    _myImageView.backgroundColor = [UIColor whiteColor];
    //打開交互
    _myImageView.userInteractionEnabled = YES;
    [self.view addSubview:_myImageView];
    
    //添加一個手勢
    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(selectImage:)];
    [_myImageView addGestureRecognizer:tapGesture];
}

//實現手勢的方法，進入相冊
-(void)selectImage:(UIButton*)sender
{   //創建ImagePickController
    UIImagePickerController *myPicker = [[UIImagePickerController alloc]init];
    
    //創建源類型
    UIImagePickerControllerSourceType mySourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    
    myPicker.sourceType = mySourceType;
    
    //設置代理
    myPicker.delegate = self;
    //設置可編輯
    myPicker.allowsEditing = YES;
    //通過模態的方式推出系統相冊
    [self presentViewController:myPicker animated:YES completion:^{
        NSLog(@"進入相冊");
    }];
 
}

#pragma mark -- 實現imagePicker的代理方法

 -(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info
{
    //取得所選取的圖片,原大小,可編輯等，info是選取的圖片的信息字典
    UIImage *selectImage = [info objectForKey:UIImagePickerControllerEditedImage];
    
    //設置圖片進相框
    self.myImageView.image = selectImage;
    [picker dismissViewControllerAnimated:YES completion:^{
        NSLog(@"模態返回") ;
    }];
}

@end

效果如下

中間有個相框，點一下進入相冊，在相冊中選擇一張圖片，點choose，出來相框的圖片就變了