IOS成长之路-调用照相机和相册功能

打开相机：

//先设定sourceType为相机，然后判断相机是否可用（ipod）没相机，不可用将sourceType设定为相片库
    UIImagePickerControllerSourceType sourceType = UIImagePickerControllerSourceTypeCamera;
//    if (![UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeCamera]) {
//        sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
//    }
    //sourceType = UIImagePickerControllerSourceTypeCamera; //照相机
    //sourceType = UIImagePickerControllerSourceTypePhotoLibrary; //图片库
    //sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum; //保存的相片
    UIImagePickerController *picker = [[UIImagePickerController alloc] init];//初始化
    picker.delegate = self;
    picker.allowsEditing = YES;//设置可编辑
    picker.sourceType = sourceType;
    [self presentModalViewController:picker animated:YES];//进入照相界面
    [picker release];

在iPhone和iPod touch上面系统始终以UIModalPresentationFullScreen模式显示presented VC。

打开相册：（区分pad和iphone）

for iphone

UIImagePickerController *pickerImage = [[UIImagePickerController alloc] init];
    if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
        pickerImage.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        //pickerImage.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
        pickerImage.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:pickerImage.sourceType];
        
    }
    pickerImage.delegate = self;
    pickerImage.allowsEditing = NO;
    [self presentModalViewController:pickerImage animated:YES];
    [pickerImage release];

会在一个新的窗口中打开

for ipad:

On iPad, UIImagePickerController must be presented via UIPopoverController

不是你想不想的问题，是苹果让你想不想的问题

UIImagePickerControllerSourceType sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    //sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum; //保存的相片
    UIImagePickerController *picker = [[UIImagePickerController alloc] init];
    picker.delegate = self;
    picker.allowsEditing = NO;//是否允许编辑
    picker.sourceType = sourceType;
    /*
     如果从一个导航按钮处呈现，使用：
     presentPopoverFromBarButtonItem:permittedArrowDirections:animated:；
     如果要从一个视图出呈现，使用：
     presentPopoverFromRect:inView:permittedArrowDirections:animated:
     
     如果设备旋转以后，位置定位错误需要在父视图控制器的下面方法里面重新定位：
     didRotateFromInterfaceOrientation:（在这个方法体里面重新设置rect）
     然后再次调用：
     - (void)presentPopoverFromRect:(CGRect)rect inView:(UIView *)view permittedArrowDirections:(UIPopoverArrowDirection)arrowDirections animated:(BOOL)animated             
     */
    //UIPopoverController只能在ipad设备上面使用；作用是用于显示临时内容，特点是总是显示在当前视图最前端，当单击界面的其他地方时自动消失。
    UIPopoverController *popover = [[UIPopoverController alloc]initWithContentViewController:picker];
    self.imagePicker = popover;
    //permittedArrowDirections 设置箭头方向
    [self.imagePicker presentPopoverFromRect:CGRectMake(0, 0, 300, 300) inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
    [picker release];
    [popover release];