Monotouch - 带有 iPad 应用程序的 UIImagePickerController

Question

我有一个仅限 iPad 的应用程序，我试图允许用户从他们的 PhotoLibrary 中选择图像，据我所知，我必须在 UIImagePickerController 中使用 UIImagePickerController >UIPopOverController。我尝试了很多不同的方法来做到这一点，但我可以让任何事情发挥作用。我看过很多代码片段，但我似乎无法让它们在 Monotouch 下工作。

有人能指出我执行此操作的正确方法吗？我非常感激。

Answer 1

我必须调用创建图像选择器的代码以及对从主线程中选取的图像做出反应的代码才能使其正常工作：

    partial void OnImport (UIButton s)
    {
        BeginInvokeOnMainThread(delegate
        {

            UIImagePickerController picker = new UIImagePickerController();
            picker.ContentSizeForViewInPopover = new System.Drawing.SizeF(320,480);

            UIPopoverController popover = new UIPopoverController(picker);

            picker.FinishedPickingImage += delegate(object sender, UIImagePickerImagePickedEventArgs e) 
            {       
                BeginInvokeOnMainThread(delegate
                {
                    UIImage image = (UIImage)info.ObjectForKey(new NSString("UIImagePickerControllerOriginalImage"));
                    picker.DismissModalViewControllerAnimated(true);
                    // do something with image
                });

            };

            picker.SourceType = UIImagePickerControllerSourceType.PhotoLibrary;     
            popover.PresentFromRect(s.Frame, this.View, UIPopoverArrowDirection.Left, true);                    
        });
    }

Answer 2

这是我在应用程序中使用的代码 - 这应该作为您使其正常工作的良好开端。

UIImagePickerController imagePicker;
UIPopoverController popOver;

void AttachImageBtnTouched(object sender, EventArgs e)
{
    if (popOver == null || popOver.ContentViewController == null)
    {
        imagePicker = new UIImagePickerController();
        popOver = new UIPopoverController(imagePicker);
        ImagePickerDelegate imgDel = new ImagePickerDelegate();
        imagePicker.Delegate = imgDel;
        imagePicker.SourceType = UIImagePickerControllerSourceType.PhotoLibrary;
    }
    if (popOver.PopoverVisible)
    {
        popOver.Dismiss(true);
        imagePicker.Dispose();
        popOver.Dispose();
        return;
    }
    else
    {
        popOver.PresentFromRect(btnAttachment.Frame, this.View, UIPopoverArrowDirection.Any, true);
    }
}

// The Delegate class looks something like

public class ImagePickerDelegate : UIImagePickerControllerDelegate
{
    public ImagePickerDelegate()
    {}

    public override void FinishedPickingMedia(UIImagePickerController picker, NSDictionary info)
    {
        UIImage image = (UIImage)info.ObjectForKey(new NSString("UIImagePickerControllerOriginalImage"));
        // do whatever else you'd like to with the image
    }
}