I am trying to create a couple of UIImageViews (preferably with a for loop) and then afterwards move them, but I don't know how because I'm having trouble figuring out how to reference them if they will be made programmatically.
So I want something like this:
for (int i = 0; i < 2; i++)
{
UIImageView *iv = [[UIImageView alloc]initWithImage:[UIImage imageNamed: picturo]];
CGRect rect = CGRectMake((i * 50) + 50,30, 25, 25);
[iv setFrame:rect];
iv.tag = i;
[self.view addSubview:iv];
}
(iv with tag of 0).center.y = 80; // <-- How do I do that!!
Obviously this example has no practical use and I could just change y value of 'rect' above to 80, but I want to know how to:
a. Create multiple uiimageviews (or any object for that matter) and be able to identify/reference/manipulate each one individually (I don't know how but I would assume by either naming them uniquely or using tags) and
b. Be able to identify/reference/manipulate an object that was created programmatically.
creating views with tags works the way you have it.
To access those views use the viewWithTag property on a view to identify one of it's subviews:
UIView* subview = [self.view viewWithTag:0];
subview.center = CGPointMake(subview.center.x, 80);
(you cannot write to a view.center's x or y, you have to recreate the whole thing. Likewise with other geometric structs such as CGSize, CGRect)
Related
For each UIImageView, I want to add the label subview to it.
Here is my class inherited form UIImageView
-(instancetype)initWithFrame:(CGRect)frame
{
if (self=[super initWithFrame:frame]) {
self.categoryLabel=[[UILabel alloc]initWithFrame:CGRectMake(frame.origin.x, frame.origin.y, frame.size.width, 50)];
self.categoryLabel.textAlignment=NSTextAlignmentCenter;
self.categoryLabel.font=[UIFont systemFontOfSize:20];
self.categoryLabel.textColor=[UIColor whiteColor];
[self addSubview:self.categoryLabel];
NSLog(#"%#",self.subviews);
}
return self;
}
-(void)setModel:(HorizontalModel *)model
{
_model=model;
self.categoryLabel.text=self.model.category;
[self sd_setImageWithURL:[NSURL URLWithString:[NSString stringWithFormat:#"XXXXX%#",self.model.imgURL]] placeholderImage:[UIImage imageNamed:#"obama"]];
}
Here is my code in the view controller.
-(void)addImage:(NSNotification *)notification
{
self.HArrayLists=notification.userInfo[#"array"];
for (int i=0; i<[self.HArrayLists count]; i++) {
JTImageView *imageView=[[JTImageView alloc] initWithFrame:CGRectMake(i*310, 0, 300, 200)];
imageView.model=[HorizontalModel restaurantsDetailWithDict: self.HArrayLists[i]];
[self.mediaScrollView addSubview:imageView];
}
self.mediaScrollView.contentSize=CGSizeMake(310*[self.HArrayLists count], 0);
}
It turns out that only the first imageView shows a label, while the rest of the imageViews show only images.
I think the core of your problem is the line:
self.categoryLabel=[[UILabel alloc]initWithFrame:CGRectMake(frame.origin.x, frame.origin.y, frame.size.width, 50)];
You are offsetting the x and y positions of the label by the x and y values of the image. This will place them outside the area of the image and with the image clipping, make them invisible. I think the line should be
self.categoryLabel=[[UILabel alloc]initWithFrame:CGRectMake(0, 0, frame.size.width, 50)];
to place all the labels at the top left corner of each image.
Having said that there are also a number of recommendations I would like to offer.
Firstly make all variable names start with a lowercase. So self.HArrayLists should be self.hArrayLists.
Secondly try and make variable names match their contents. So again looking at self.HArrayLists, perhaps something like self.imageData.
Next I would have done the composition differently. I would have a UIView to which I add both the UILabel and UIImageView instances. Using a parent view like this to layout two sub views often makes life easier.
I would also look into using a UICollectionView and UICollectionViewController rather than a UIScrollView. It will take you a bit of work to get your heads around how collection views work. But you will gain in terms of performance and better layout management.
Finally, study up on constraints. They're an essential part of building modern apps that can easily adapt to different sized screens, rotation and layouts.
You need to set as categoryLabel's frame properly.
self.categoryLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, frame.origin.y, frame.size.width, 50)];
I'm developing an app for iPhone and I have a strange problem. I tried to solve this by myself but after 3 days I didn't found a solution anyway.
I have a scrollview in which I dynamically create other views and subviews, this is the code:
for (int i=0; i<dim; i++) {
UITextView *posted_nick= [[UITextView alloc] initWithFrame:CGRectMake(paddWidth, heightUpdateImageScrollview+paddHeight/2, screenWidth-2*paddWidth, 37)];
//textview customization...
[imagesScrollView addSubview:posted_nick];
row_images_like = [[UIView alloc] initWithFrame:CGRectMake(paddWidth,heightUpdateImageScrollview+paddHeight+37+heightImageInScrollView,screenWidth-2*paddWidth,80)];
//set the tag = id
row_images_like.tag = [id_image intValue];
UIImageView *like_mini = [[UIImageView alloc] initWithFrame:CGRectMake(0,15,25,25)];
//imageview customization...
//tag = id+1..
NSInteger x = [id_image intValue] + 1;
number_like.tag = x;
[row_images_like addSubview:like_mini];
UITextView *number_like = [[UITextView alloc] initWithFrame:CGRectMake(paddWidth*5/2,10,55,37)];
//textview customization...
//tag = id+2..
NSInteger x = [id_image intValue] + 2;
number_like.tag = x;
[row_images_like addSubview:number_like];
[imagesScrollView addSubview:row_images_like];
}
Now, all works great and when I click on the image view "like_mini", I can find the other views in the same row with the appropriate tag
(UIView *thisView = (UIView*)[imagesScrollView viewWithTag:ID_IMAGE];)
The problem is where I update my scrollview. When the user scrolls to the top, if there are new images to show, I call the same function that creates the views, and all the other views (that already exist) are moved some down. Why, when I try to find a view by tag in my scrollview, all works at the first time, but don't work for the new images created with the same code?
If i remove all the views in the scrollview, before adding the new views, it works. But i don't want to remove the oldest view.
When it works, I have in my console the view (row_images_like) with tag.
When it doesn't work, I receive a _UITextContainerView. What is this?
Hope I explained myself.
Hi there the only reason the images moves down is because you are not assigning the proper tags, please give appropriate value of tag to uiview, uiimageview and uitextview.
row_images_like.tag = [id_image intValue] + 1000;
For fetching the view get it done similarly what you did before only add thousand to it.
UIView *thisView = (UIView*)[imagesScrollView viewWithTag:ID_IMAGE+1000];
Also one error :
number_like.tag = x;
How does the above line object i.e "Number_like" comes before initialising it and change the tag value of other objects to "+2000" and "+3000"
Try removing all views added to scrollview, before loading scrollview again
Write this line above for loop
for (UIView *v in [imagesScrollView subviews])
{
[v removeFromSuperview];
v = nil;
}
Hello, i want to create relative constraints between 3 elements.
And when resized from 4 to 3.5inch those constraints resizing to the new size while objects keep their size;
There is a way to create flexible spacing between elements with the help of constraints. The way is to use a view for the spacing not a constraint. There is event a sample in the official documentation.
https://developer.apple.com/library/ios/documentation/userexperience/conceptual/AutolayoutPG/AutoLayoutbyExample/AutoLayoutbyExample.html
Look at the section named "Spacing and Wrapping".
Don't use static height and width. use following code for calculating height and width.
int width = self.view.frame.size.width;
int height = self.view.frame.size.height;
In this way set X and Y co-ordinate for your element.
Refer this Code -
int imageX = 2,imageY = 2;
int count1 = 0;
for (int i = 0; i < [mainMenuColumn1Array count]; i++) {
count1++;
MenuClass *menuClass = [[MenuClass alloc] init];
menuClass = [mainMenuColumn1Array objectAtIndex:(count1 - 1)];
UIButton *menuBtn = [UIButton buttonWithType:UIButtonTypeCustom];
menuBtn.frame = CGRectMake(imageX, imageY, (width/2)-4, (height/3)-4);
menuBtn.tag = count1;
[menuBtn addTarget:self action:#selector(mainMenu1Action:) forControlEvents:UIControlEventTouchUpInside];
menuBtn.backgroundColor = [UIColor colorWithRed:17.0/255.0 green:116.0/255.0 blue:239.0/255.0 alpha:1.0];
[mainView1 addSubview:menuBtn];
imageY = imageY + height/3;
imageX = 2;
}
Here I have add UIButtons dynamically. And I set XY co-ordinates dynamically. This is a generic code for all size devices.
You can't do this in interface builder, as far as I am aware, because you can't specify multipliers on constraints via interface builder. However, you can do it quite easily in code, particularly using a nice auto layout helper category available via Github or cocoapods. (Disclaimer - I wrote the category!).
The category contains a method to distribute an array of views evenly along a specified axis, and under the hood it creates constraints using multipliers of the containing view's dimensions - so for two views, the centres would be 0.33 and 0.66 of the way along the relevant axis, for example.
To use this for a view primarily built in interface builder, you'd use placeholder constraints (removed at run time) then add the category constraints after viewDidLoad.
I'm working in Xcode and i have a loop cycle in which i dynamically create UIImageViews and UITextviews and insert them in a UIScrollView. In every row, i create 4 UIImageViews and 2 UITextViews, so the code looks like this:
for (int i=0; i<dim; i++){
UITextView *textView1= [[UITextView alloc] initWithFrame:CGRectMake(0, 0, screenWidth/2, 37)];
UITextView *textView2= [[UITextView alloc] initWithFrame:CGRectMake(screenWidth/2, 0, screenWidth/2, 37)];
UIImageView *imageView1 = [[UIImageView alloc] initWithFrame:CGRectMake(0,50,screenWidth/4,100)];
UIImageView *imageView2 = [[UIImageView alloc] initWithFrame:CGRectMake(screenWidth/4,50,screenWidth/4,100)];
UIImageView *imageView3 = [[UIImageView alloc] initWithFrame:CGRectMake(screenWidth/2,50,screenWidth/4,100)];
UIImageView *imageView4 = [[UIImageView alloc] initWithFrame:CGRectMake(screenWidth*3/4,50,screenWidth/4,100)];
}
The code to set images in UIImageViews, text in UITextViews and show them in the UIScrollView works great and i don't post it because it's too long.
My problem is: when i click on an image, i call methods in which i want to make change to the ImageViews and TextViews of the same row, how can i identify them?
Detecting the image clicked is not a problem using the recognizer.view, to detect other images of the same row i tried to set a tag to the views and then call "viewWithTag" to find them, but i have problems because the elements of the same row have the same tag value and i make confusion.
My target is for example:
When i click on imageView1 in the first row should change image in imageView3 of the same row.
When i click on imageView3 in the fourth row should change text in textView2 of the same row.
And so on..
Is there any alternative method without using the tag attribute?
I hope I explained myself
You can use the tag property, but without using the same tag more then once. Some little math should do the trick to identify views in the same row by their tags...
BUT:
I wouldn't recommend using tags. Make yourself a custom view class, e.g. MyRow, containing the 6 views belonging together as subviews. From there you can go anywhere.
Got a problem, invent an object. Always works.
BIGGER BUT: I'd strongly recommend to go with UICollectionView or UITableView.
UIView has a "tag" property, which you can use for anything you want. The default value is 0 and it doesn't do anything at all, except store the value.
Typically you would set the tag to be an array index.
So you could do:
textView1.tag = i;
textView2.tag = i;
imageView1.tag = i;
imageView2.tag = i;
imageView3.tag = i;
imageView4.tag = i;
Or perhaps something more clever, like:
textView1.tag = 1000000 + i;
textView2.tag = 2000000 + i;
imageView1.tag = 3000000 + i;
imageView2.tag = 4000000 + i;
imageView3.tag = 5000000 + i;
imageView4.tag = 6000000 + i;
Or maybe you could have an array property mapping them:
#property NSMutableArray tagMap;
textView1.tag = self.tagMap.count;
[self.tagMap addObject:#{#"var": #"textView1", #"index":[NSNumber numberWithInteger:i]}];
I have a view. I would like to be able to put 1-3 UIPickerViews in it. The number of UIPickerViews is determined by the value of a variable myVariable. Each UIPickerView is different. Some of the values for myVariable mean that there will only be one UIPickerView in the view, but some mean that I will have to put 2 or 3 in the view, and it will be laid out vertically (so one UIPickerView is directly above the other). Right now, every case where myVariable means that it needs only 1 UIPickerView, I'm putting them in the view like this:
if (myVariable == kNeedsOnlyOnePicker)
{
myPicker = [[UIPickerView alloc] initWithFrame:self.view.frame];
[myPicker setDelegate:self];
[myPicker setDataSource:self];
myPicker.showsSelectionIndicator = YES;
[self.view addSubview:myPicker];
}
However, I'm just not sure how to tell the code something like this:
if (myVariable == kNeedsTwoPickers)
{
// put myPicker and myOtherPicker in self.view,
// and put myPicker above myOtherPicker.
}
I have a hunch I won't be able to use the .xib to do something like this, because I won't be able to set up different layouts (e.g. picker 1 above picker 2, picker 2 above picker 3, only picker 3).
TL;DR how do I programmatically say, "this subview will go above this other subview" or "this picker will go above this other picker"?
Specific methods/examples and/or general ideas would be great.
Thanks!
I found that I could set the frame for the subview and calculate its coordinates.
- (void)layout
{
for (int i= 0; i < [self.view.subviews count]; i++)
{
// calculate x, y, width, and height
UIView *subview = [self.view.subviews objectAtIndex:i];
subview.frame = CGRectMake(x, y, width, height);
}
}