ios - 从按钮启动图像选择器不起作用

Question

我使用标准标签栏应用程序作为测试应用程序的基础。

我还尝试使用在 github 上找到的 ELCAlbumPickerController 类。

启动照片选择器的按钮和 uiscrollview 位于 Secondview.xib

以下是SecondViewController.h中的代码

#import <UIKit/UIKit.h>
#import "ELCImagePickerController.h"


@interface SecondViewController : UIViewController       <ELCImagePickerControllerDelegate,UINavigationControllerDelegate, UIScrollViewDelegate>{
    UIWindow *window;
    SecondViewController *viewController;
    IBOutlet UIScrollView *scrollview;

}

@property (nonatomic,retain) IBOutlet UIWindow *window;
@property (nonatomic,retain) IBOutlet SecondViewController *viewController;
@property (nonatomic,retain) IBOutlet UIScrollView *scrollview;

-(IBAction)launchController;

@end

以下内容位于 SecondViewController.m

#import "myappAppDelegate.h"
#import "SecondViewController.h"
#import "ELCImagePickerController.h"
#import "ELCAlbumPickerController.h"

@implementation SecondViewController

@synthesize window;
@synthesize viewController;
@synthesize scrollview;


/*
// Implement viewDidLoad to do additional setup after loading the view, typically from  a nib.*/
- (void)viewDidLoad
{

    //[self launchController:self];
    [super viewDidLoad];
}


- (BOOL)shouldAutorotateToInterfaceOrientation:  (UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

-(IBAction)launchController {

    ELCAlbumPickerController *albumController = [[ELCAlbumPickerController alloc] initWithNibName:@"ELCAlbumPickerController" bundle:[NSBundle mainBundle]];    
    ELCImagePickerController *elcPicker = [[ELCImagePickerController alloc] initWithRootViewController:albumController];
    [albumController setParent:elcPicker];
    [elcPicker setDelegate:self];

    //myappAppDelegate *app = (myappAppDelegate *)[[UIApplication sharedApplication] delegate];
    SecondViewController *app = (SecondViewController *)[[UIApplication sharedApplication] delegate];
    [app.viewController presentModalViewController:elcPicker animated:YES];
    [elcPicker release];
    [albumController release];
}

#pragma mark ELCImagePickerControllerDelegate Methods

- (void)elcImagePickerController:(ELCImagePickerController *)picker didFinishPickingMediaWithInfo:(NSArray *)info {

    [self dismissModalViewControllerAnimated:YES];

    for (UIView *v in [scrollview subviews]) {
    [v removeFromSuperview];
    }

CGRect workingFrame = scrollview.frame;
workingFrame.origin.x = 0;

for(NSDictionary *dict in info) {

    UIImageView *imageview = [[UIImageView alloc] initWithImage:[dict objectForKey:UIImagePickerControllerOriginalImage]];
    [imageview setContentMode:UIViewContentModeScaleAspectFit];
    imageview.frame = workingFrame;

    [scrollview addSubview:imageview];
    [imageview release];

    workingFrame.origin.x = workingFrame.origin.x + workingFrame.size.width;
}

[scrollview setPagingEnabled:YES];
[scrollview setContentSize:CGSizeMake(workingFrame.origin.x,   workingFrame.size.height)];
}

 - (void)elcImagePickerControllerDidCancel:(ELCImagePickerController *)picker {

[self dismissModalViewControllerAnimated:YES];
}


- (void)didReceiveMemoryWarning
{
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc. that aren't in use.
}


- (void)viewDidUnload
   {
    [super viewDidUnload];

    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
    }


- (void)dealloc
{ 
    [super dealloc];
}

@end

当您单击该按钮时，您会收到一条消息“正在解除分配 ELCImagePickerController”，因此它正在调用 ELCImagePickerController 类，但它只是不显示图像选择器。任何想法将不胜感激。

谢谢

Answer 1

在 launchController() 方法中，您将 appDelegate 转换为 viewController，这在逻辑上是错误的。您需要使用实际的viewController来presentModalViewController。尝试:

[self presentModalViewController:elcPicker animated:YES];