append items to UITableView or UICollectionView

// from stack overflow with UITableView

// build the index paths for insertion

    // since you're adding to the end of datasource, the new rows will start at count

    NSMutableArray*indexPaths =[NSMutableArray array];

    NSInteger currentCount = self.datasource.count;

    for(int i =0; i < dataToAdd.count; i++)

    {

        [indexPaths addObject:[NSIndexPath indexPathForRow:currentCount+i inSection:0]];

    }

    // do the insertion

    [self.dataSource addObjects:dataToAdd];

    // tell the table view to update (at all of the inserted index paths)

    [self.tableView beginUpdates];

    [self.tableView insertRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationTop];

    [self.tableView endUpdates];

// in my real code with UICollectionView

- (void)getMoreServerData

{

// 새로운 아이템을 컬렉션의 끝에 추가

NSMutableArray *indexPaths = [NSMutableArray array];

                NSInteger currentCount = items.count;

                for (int i = 0; i < model.storesModelArray.count; i++) {

                    [indexPaths addObject:[NSIndexPath indexPathForRow:currentCount+i inSection:0]];

                }

                [items addObjectsFromArray:model.storesModelArray];

                [self.collectionView insertItemsAtIndexPaths:indexPaths];

}

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {

// 리스트의 마지막에 도착한 경우 attach data

    if (scrollOffset + scrollView.frame.size.height == scrollView.contentSize.height)

    {

        [self getMoreServerData];

    }

}

grid crop with uiimage

이미지를 grid 형태로 잘라서 view에 add하는 예제.

- (void)viewDidLoad

{

    [super viewDidLoad];

    UIImage *scaledImage = [self scaleWithImage:[UIImage imageNamed:@"37.jpg"] scaledToSize:self.view.frame.size];

    self.originalImageView = [[UIImageView alloc] initWithImage:scaledImage];

    [self prepareSlices:10 :10];

}

-(void)prepareSlices:(uint)row :(uint)col

{

    float flagX = _originalImageView.image.size.width / _originalImageView.frame.size.width;

    float flagY = _originalImageView.image.size.height / _originalImageView.frame.size.height;

    

    float _width    = _originalImageView.frame.size.width / col;

    float _height   = _originalImageView.frame.size.height / row;

    

    float _posX = 0.0;

    float _posY = 0.0;

    

    for (int i = 1; i <= row * col; i++) {

        

        UIImageView *croppedImageVeiw = [[UIImageView alloc] initWithFrame:CGRectMake(_posX, _posY, _width, _height)];

        UIImage *img = [self getCropImage:CGRectMake(_posX * flagX,_posY * flagY, _width * flagX, _height * flagY)];

        croppedImageVeiw.image = img;

        

        croppedImageVeiw.layer.borderColor = [[UIColor whiteColor] CGColor];

        croppedImageVeiw.layer.borderWidth = 1.0f;

        

        [self.view addSubview:croppedImageVeiw];

        

        _posX += _width;

        

        if (i % col == 0) {

            _posX = 0;

            _posY += _height;

        }

    }

}

-(UIImage*)getCropImage:(CGRect)cropRect

{

    CGImageRef image = CGImageCreateWithImageInRect([_originalImageView.image CGImage],cropRect);

    UIImage *cropedImage = [UIImage imageWithCGImage:image];

    CGImageRelease(image);

    return cropedImage;

}

- (UIImage *)scaleWithImage:(UIImage *)image scaledToSize:(CGSize)newSize {

    //UIGraphicsBeginImageContext(newSize);

    // In next line, pass 0.0 to use the current device's pixel scaling factor (and thus account for Retina resolution).

    // Pass 1.0 to force exact pixel size.

    UIGraphicsBeginImageContextWithOptions(newSize, NO, 1.0);

    [image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];

    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return newImage;

}

UIView가 화면에 추가되서 보여지는지 안보여지고있는지 체크하는 방법

UIView.window를 체크하면 됨.

<예제>

MyUIViewController.h

UIView *popupView;

MyUiViewController.m

..

popupView = [UIView alloc] init];

[self.view addSubView:popupView];

if(popupView.Window  != nil)

    NSLog(@"you can see popup now");

....

[popupView removeFromSuperView];

if(popupView.Window  == nil)

    NSLog(@"you can't see popup now");

uiview 터시하면 keyboard 사라지게 하는 방법

UIView 의 - (BOOL)endEditing:(BOOL)force  함수를 사용하면 됨.


예제)

MyViewController.m
...
..

[self.view endEditing:NO];

string에서 keyword를 찾아 빨간색으로 표시하기

// search matching keyword

    NSRegularExpression *regex = [NSRegularExpression

                                  regularExpressionWithPattern:searchKeyword

                                  options:NSRegularExpressionCaseInsensitive

                                  error:nil];

    [regex enumerateMatchesInString:fullString options:0 range:NSMakeRange(0, [fullString length]) usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop){

        [attributedText addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:result.range];

        

        [self.label setAttributedText:attributedText];

    }];