How does one code this scenerio in iphone sdk?
In an expense app, when you want to add an expense, this view comes up.
After selecting "Clothing," another view slides up with a UIPickerView control that has a "done" button which will dismiss the UIPickerView. Below is a screen shot after hitting "Clothing."
I'm trying to figure out how one would slide up the UIPickerView half way up the screen with a "done" button on top of the "New Expense" view?
thank you in advance!
Use CoreAnimation and make the UIView with move from bottom to top.. and change the hidden property to true from false when required and vice versa..
Multiple UIViews can be nested as required take advantage of this to achieve what u need
You implement the UIPickerDelegate, then implement the methods that belongs to the UIPickerView.
So your interface file must contain this:
#interface YourViewController : UIViewController <UIPickerViewDelegate, UIPickerViewDataSource> {
Your viewController them implements these, or more, methods:
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component;
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component;
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component;
t´You would then instantiate the picker, set its delegate and all other properties you need it to conform to.
You could then hook up a "listener" for keeping track on when it changed.
[datePicker addTarget:self action:#selector(didChangeDate) forControlEvents:UIControlEventValueChanged];
A good place to start is the UICatalog example from the Apple developer site.
This has a lot of Picker code and a bunch of other stuff that could help getting in the mindset Apple uses for building stuff with UIElements.
Hope it helps:) it is a large subject.
This post helped me; might help others: http://sdhillon.com/animated-uipickerview
Related
I need to perform some code when the user stop scrolling the picker, in other way, when the picker stop scrolling. The logic i want to follow is, once the picker stop scrolling, i get the current value and i do some database queries basing on that value.
In the picker view documentation, i don't see a delegate method that can help on such task. Any thoughts? thanx in advance.
whenever you scroll the picker view, didSelect delegate method call at the end of scroll
- (void)pickerView:(UIPickerView *)thePickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
NSLog(#"Selected %i. ", row);
/// do it here your queries
}
try with above example and check your console
The delegate class has a method pickerView:didSelectRow:inComponent:, that you can use to detect the selected row.
I want to make multiple UIPicker with following requirements -
Make Multiple UIPicker (let's call them Picker1 and Picker2)
Value of Picker2 should automatically change based upon value of Picker1 (for instance I Picker1 has countries and Piker2 should display cities in that country)
also I would like to change the data in UIView based upon the value selected from Picker1 and Picker2 (lets say we select "UK" and city as "London" then UIView should talk only about "places to visit in london"
I know it sounds like lot of asking - your help would be highly appreciated, Thanks in advance.
First, your ViewController(the one with the picker) should implement the UIPickerViewDelegate.
You should than use this method:
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
It gets called every time you change a the selected row on any of the components of your picker.
For example when this gets called, you should change the UIView element to the appropriate value.
This is also the moment to reload Component2 (or whatever you want to call it) of your picker like this.
[picker reloadComponent:2];
or
[picker reloadAllComponents];
I'm still very new to cocoa touch so please excuse any terminology that I may have got wrong.
I have a bunch of images in my bundle consecutively named image0.png, image1.png etc...
I have a picker in a viewcontroller and an instance variable that keeps track of the current row.
When a user clicks a button I want to be able to create a uiImageView object (and first test whether the view already exists) based on the row number, ie: uiImageView *imageView1 for row1.
Is this possible or would it just be easier to create a line of code for each possible case?
I hope this makes sense, and thanks in advance for anyone that can shed any light!
Why not just create one UIImageView in Interface Builder and then swap out the image it's displaying depending on your picker index?
Implement:
- (void)pickerView:(UIPickerView *)pickerView
didSelectRow:(NSInteger)row
inComponent:(NSInteger)component
{
[imageView setImage:[imagesArray objectAtIndex:row]];
}
Where imageView is an instance variable (IBOutlet) connected to the image view control in Interface Builder.
Ok, that makes sense.
I think what I was trying to do was take lazy loading to the extreme by only creating the uiImage object and the uiImageView object the first time it was called on from the picker (having clicked the "go" button).
I anticipate having around 40 images that will fill the screen.
Programatically, would this be an acceptable method for this number of images?
Thanks very for the responses guys.
I have a UIPickerView, in it's delegate I'm trying to customize the view for a row. I'm using the 3.1 SDK.
So in the delegate I have:
- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view {
// view.backgroundColor = [UIColor redColor];
return view;
}
From the apple docs:
If the previously used view (the view parameter) is adequate, return that. If you return a different view, the previously used view is released. The picker view centers the returned view in the rectangle for row.
When I run this, my UIPickerView control doesn't have any items in it, and after a short while crashes.
When I remove this particular method (which is optional for the delegate), I can see the labels I set via the titleForRow method, and it will no longer crash.
I'm pretty new to cocoa (and cocoa-touch), I'm not sure the view.backgroundColor thing will work, but even when returning the unmodified old view (which I must do anyway for most rows) crashes my app.
Am I doing something wrong?
Yes, you implement either –pickerView:titleForRow:forComponent: or –pickerView:viewForRow:forComponent:reusingView:, but not both. What is happening is that it is not calling your –pickerView:titleForRow:forComponent: because it is using your –pickerView:viewForRow:forComponent:reusingView:. You are returning the reusingView: parameter, but that is nil the first time, because there was no "previously used view" for that row.
I am trying to create a Dialog Box in which contains a UIPickerView. I can get it to work without the Subview tied around it but I always end up with an Uncaught error. Any help?
Well apparently I fixed by messing with this method -(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component