Question

我添加了一个简单的集合视图，我添加了从后端获取的项目，当我将所有对象添加到nsmutablearray时，它占用的内存更少但是当我在滚动集合视图时将获取的对象添加到NSObject时需要更多的内存

这是一个示例代码

myObjectModel.h

#import <Foundation/Foundation.h>

@interface myObjectModel: NSObject


@property (nonatomic, strong) NSString *objectTitle;
@property (nonatomic, strong) NSString *objectDesc;
@property (nonatomic, strong) NSString *objectImgURL;

- (id)initWithObjectTitle:(NSString *)dTitle
             objectImgURL:(NSString *)dObjectImgURL
               objectDesc:(NSString *)dObjectDesc;
@end

myObjectModel.m

#import "myObjectModel.h"

@implementation myObjectModel

- (id)initWithObjectTitle:(NSString *)dTitle
             objectImgURL:(NSString *)dObjectImgURL
               objectDesc:(NSString *)dObjectDesc {
    self = [super init];
    if (self) {
       self.objectTitle = dTitle;
       self.objectImgURL = dObjectImgURL;
       self.objectDesc = dObjectDesc;
    }
    return self;
}

@end;

然后我将这个标题导入我的UIViewController，它有一个collectionview，同时获取所有对象，我添加这个方法来添加这些对象，然后将它们保存到nsmutablearray

     BackendlessDataQuery *query = [BackendlessDataQuery query];
          query.queryOptions.pageSize = @(100); //set page size
        [[backendless.persistenceService of:[Channels class]] find:query response:^(BackendlessCollection *backendlessObjects) {

            NSArray *currentPage = [backendlessObjects getCurrentPage];
    NSMutableArray *arrData = [[NSMutableArray alloc]init];
            for (Objects *objects in currentPage) {

                @autoreleasepool {

   myObjectModel *dataItem = [[myObjectModel alloc]initWithObjectTitle:backendlessObjects.title
             objectImgURL:backendlessObjects.image
               objectDesc:backendlessObjects.Desc;



        [arrData addObject:dataItem];
    }
//Test is a nsarray added in the header file
self.test = arrData;
[self.collectionView reloadData];
} error:^(Fault *fault) {



    }];

这是我添加到我的收藏数据源

的内容

#pragma mark - UICollectionViewDatasource

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView; {
    return 1;
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{

    return [test count];
}

    - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{

        myCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"data" forIndexPath:indexPath];

       myObjectModel *dataItem = (myObjectModel*)[test objectAtIndex:indexPath.row];
       // cell.objectTitle.text = dataItem.objectTitle;



        [cell.channelImg sd_setImageWithURL:[NSURL URLWithString:dataItem.objectImgURL] placeholderImage:[UIImage imageNamed:@"NoImage.png"]];

        return cell;
    }

当我运行此代码时，所有对象都将出现在collectionview中，但滚动时内存不断增加。

Answer 1

没有理由通过使用测试阵列增加内存，原因是使用此

[cell.channelImg sd_setImageWithURL:[NSURL URLWithString:dataItem.objectImgURL] placeholderImage:[UIImage imageNamed:@"NoImage.png"]];

这将从URL异步下载图像。如果您在上面注释，那么它可能不会增加内存。

内存问题nsobject和nsmutablearray UICollectionView

1 个答案: