从解析类中获取图像

Question

初学者在这里。 我已经设法将文本从Parse类传递到表视图。 在同一个班级中，我还有另一列放置关联的图像文件，因此我无法获得该图像文件。 如果您能在这个问题上帮助我，我会很高兴。 解析类的名称为News，而我想获取的列为imageFile。 这是我的代码。

.h文件

#import <UIKit/UIKit.h>
#import <Parse/Parse.h>
#import "TableCell.h"

@interface ViewController : UIViewController <UITableViewDelegate> {

NSArray *events;
}
@property (weak, nonatomic) IBOutlet UITableView *newsTable;

@end

.m文件

#import "ViewController.h"
#import "TableCell.h"

@interface ViewController ()

@end

@implementation ViewController
@synthesize newsTable;


- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self performSelector: @selector(retreiveFromParse)];

}

- (void) retreiveFromParse {
PFQuery *retrieveEvents = [PFQuery queryWithClassName:@"News"];
[retrieveEvents findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
    if (!error) {
        events = [[NSArray alloc] initWithArray:objects];
    }
    [newsTable reloadData];
}];
}

//*********************Setup table of folder names ************************

//get number of sections in tableview
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
// Return the number of sections.
return 1;
}

//get number of rows by counting number of folders
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return events.count;
}

//setup cells in tableView
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath             *)indexPath {

//setup cell
static NSString *CellIdentifier = @"EventCell";
TableCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

PFObject *tempObject = [events objectAtIndex:indexPath.row];

cell.TitleLabel.text = [tempObject objectForKey:@"Event"];

return cell;
}


//user selects folder to add tag to
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
NSLog(@"cell tapped");
}



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

@end

我的手机

#import <UIKit/UIKit.h>
#import <Parse/Parse.h>

@interface TableCell : UITableViewCell
@property (strong, nonatomic) IBOutlet UILabel *TitleLabel;


@end

我的手机

#import "TableCell.h"

@implementation TableCell
@synthesize TitleLabel;

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
    // Initialization code
}
return self;
}



- (void)setSelected:(BOOL)selected animated:(BOOL)animated
{
[super setSelected:selected animated:animated];

// Configure the view for the selected state
}

@end

Answer 1

刚过

PFObject *tempObject = [events objectAtIndex:indexPath.row];
cell.TitleLabel.text = [tempObject objectForKey:@"Event"];

在下面的行中写..

PFFile *imageFile = [tempObject objectForKey:@"image"];
PFImageView *imageView = [[PFImageView alloc] init];
imageView.file = imageFile;
[imageView loadInBackground:^(UIImage *img,NSError *error){

    if(!error)
    {
        UIImageView *yourImageView = [[UIImageView alloc] init];
        yourImageView.image = imageView.image;
        /*OR*/
        cell.imageView.image = imageView.image;
    }
}];

这可能会帮助您。

Answer 2

这将获取关联的文件并将其放在cell.imageView中，该文件是PFImageView（UIImageView的Parse版本）：

 PFObject *tempObject = [events objectAtIndex:indexPath.row];
 cell.TitleLabel.text = [tempObject objectForKey:@"Event"];   

 PFFile *imageFile = [tempObject objectForKey:@"imageFile"];
 if (imageFile) {
     cell.imageView.file = imageFile;
     [cell.imageView loadInBackground];
 } else {
     cell.imageView.image = [UIImage imageNamed:@"AvatarPlaceholder.png"];
 }