Question

我正在开发一个IOS项目，我需要能够进入一个包含MWPhotoBrowser的ViewController。

目前，我已经创建了一个PhotoGalleryController并将其用作MWPhotoBrowser的容器，因为MWPhotoBrowser是UIViewController的子类。

然而，当我在模拟器中启动应用程序时，我得到一个空白的屏幕，中间有一个圆圈，表示已加载PhotoBrowser，但没有返回照片。

我继续记录了我所有的委托方法，发现正在调用numberOfPhotos但是实际上应该返回MWPhoto对象的函数甚至都没有被调用过！

我不太确定为什么即使我在容器ViewController中实现了所有正确的委托方法，照片对象的实际加载也永远不会完成。

我检查了API调用给出的响应输出，并打印出self.photoList。这些似乎很好，所以我不确定为什么它不会返回任何照片。

PhotoGalleryController.m

#import "PhotoGalleryController.h"
#import "MZApi.h"
#import "MZUser.h"

@implementation PhotoGalleryController


- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    //Make the HTTP request and setup the photo array in MZUser. Change from "usertext" later. 
    [MZApi loadOwnPhotoWithUserID:@"usertext" andCompletionHandler:^(NSMutableArray *photos, NSError *error) {
        if(photos!=nil){
            self.userPhotoList = photos;
            [[MZUser getCurrentUser]setPhotoList:self.userPhotoList];
            //NSLog(@" %@", self.userPhotoList);
            //Should currently be null because CurrentUser is not created yet.
        }
        else{
            NSLog(@"Failed to allocate photos!");
        }

    }];


    MWPhotoBrowser *browser = [[MWPhotoBrowser alloc]initWithDelegate:self];



    browser.displayActionButton = YES; // Show action button to allow sharing, copying, etc (defaults to YES)
    browser.displayNavArrows = NO; // Whether to display left and right nav arrows on toolbar (defaults to NO)
    browser.displaySelectionButtons = NO; // Whether selection buttons are shown on each image (defaults to NO)
    browser.enableGrid = YES; // Whether to allow the viewing of all the photo thumbnails on a grid (defaults to YES)
    browser.startOnGrid = YES; // Whether to start on the grid of thumbnails instead of the first photo (defaults to NO)
    [self.view addSubview:browser.view];



}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(NSUInteger) numberOfPhotosInPhotoBrowser:(MWPhotoBrowser *)photoBrowser{
    return [self.userPhotoList count];

}
- (id <MWPhoto>)photoBrowser:(MWPhotoBrowser *)photoBrowser photoAtIndex:(NSUInteger)index{

    if(index<self.userPhotoList.count){
        NSString *temp = [[self.userPhotoList objectAtIndex:index]file_url];
        MWPhoto *photo = [MWPhoto photoWithURL:[NSURL URLWithString:temp]];
        return photo;
    }
    return nil;
}
-(id <MWPhoto>) photoBrowser:(MWPhotoBrowser *)photoBrowser thumbPhotoAtIndex:(NSUInteger)index{
    NSLog(@"Thumb Delegate Called!");
    if(index<self.userPhotoList.count){
        NSString *temp = [[self.userPhotoList objectAtIndex:index]file_url];
        MWPhoto *photo = [MWPhoto photoWithURL:[NSURL URLWithString:temp]];
        return photo;
    }
    return nil;
}


@end

PhotoGalleryController.h

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

@interface PhotoGalleryController : UIViewController <MWPhotoBrowserDelegate>
@property(strong, nonatomic) NSMutableArray * userPhotoList;

- (NSUInteger)numberOfPhotosInPhotoBrowser:(MWPhotoBrowser *)photoBrowser;
- (id <MWPhoto>)photoBrowser:(MWPhotoBrowser *)photoBrowser photoAtIndex:(NSUInteger)index;
- (id <MWPhoto>)photoBrowser:(MWPhotoBrowser *)photoBrowser thumbPhotoAtIndex:(NSUInteger)index;

@end

服务器响应示例：

(
        {
        dislikes = 0;
        "file_url" = "http://localhost:3000/static/photos/2.jpg";
        likes = 0;
        "photo_id" = 2;
        "user_id" = kai1234;
    },
        {
        dislikes = 4;
        "file_url" = "http://localhost:3000/static/photos/1.jpg";
        likes = 5;
        "photo_id" = 1;
        "user_id" = kai1234;
    }
)

Answer 1

当您使用块加载照片时，您正在添加浏览器进行查看，通常在使用块加载照片时会有延迟，因此浏览器将获得一个空对象。

您的代码应该看起来像

#import "PhotoGalleryController.h"
#import "MZApi.h"
#import "MZUser.h"

@implementation PhotoGalleryController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    //Make the HTTP request and setup the photo array in MZUser. Change from "usertext" later. 

    self.userPhotoList = [NSMutableArray array];
    [MZApi loadOwnPhotoWithUserID:@"usertext" andCompletionHandler:^(NSMutableArray *photos, NSError *error) {
        if(photos!=nil){
            self.userPhotoList = photos;
            [[MZUser getCurrentUser] setPhotoList:self.userPhotoList];
            //NSLog(@" %@", self.userPhotoList);
            //Should currently be null because CurrentUser is not created yet.

            for (int i = 0; i < photos.count; i++)
            {
                [self.userPhotoList addObject:[MWPhoto photoWithURL:[NSURL URLWithString:[[photos objectAtIndex:i] file_url]]];
            }

            MWPhotoBrowser *browser = [[MWPhotoBrowser alloc]initWithDelegate:self];
            browser.displayActionButton = YES; // Show action button to allow sharing, copying, etc (defaults to YES)
            browser.displayNavArrows = NO; // Whether to display left and right nav arrows on toolbar (defaults to NO)
            browser.displaySelectionButtons = NO; // Whether selection buttons are shown on each image (defaults to NO)
            browser.enableGrid = YES; // Whether to allow the viewing of all the photo thumbnails on a grid (defaults to YES)
            browser.startOnGrid = YES; // Whether to start on the grid of thumbnails instead of the first photo (defaults to NO)
            [self.view addSubview:browser.view];
        }
        else{
            NSLog(@"Failed to allocate photos!");
        }

    }];
}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(NSUInteger) numberOfPhotosInPhotoBrowser:(MWPhotoBrowser *)photoBrowser{
    return [self.userPhotoList count];

}
- (id <MWPhoto>)photoBrowser:(MWPhotoBrowser *)photoBrowser photoAtIndex:(NSUInteger)index{

    if(index<self.userPhotoList.count){
        return [self.userPhotoList objectAtIndex:index];
    }
    return nil;
}
-(id <MWPhoto>) photoBrowser:(MWPhotoBrowser *)photoBrowser thumbPhotoAtIndex:(NSUInteger)index{
    NSLog(@"Thumb Delegate Called!");
    if(index<self.userPhotoList.count){
        return [self.userPhotoList objectAtIndex:index];
    }
    return nil;
}


@end

未调用MWPhotoBrowser空白屏幕/委托方法

1 个答案: