How to create a UIScrollView Programmatically?

问题:

Alright, so the key here is I'm not using IB at all, because the View I'm working with is created programmatically. The UIView covers the lower half the screen, and has a bunch of buttons on it. However, I want to add more buttons to the UIView, without making it any larger. To do so, I want to make a UIScrollView inside the view, which will allow me to add more buttons off screen so the user can scroll to them. I think that's how it works.

self.manaView = [[[UIView alloc] initWithFrame:frame] autorelease];
self.manaView.backgroundColor = [UIColor purpleColor];

UIScrollView *scroll = [UIScrollView alloc];
scroll.contentSize = CGSizeMake(320, 400);
scroll.showsHorizontalScrollIndicator = YES;
[self.manaView addSubview:scroll];

The first part of the code iniates my UIView, which works great, but I can't figure out how to make the UIScrollView programmatically and add it to the view, and then add the buttons to it.

UIButton *ret2 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
ret2.tag = 102;
ret2.frame = CGRectMake(255, 5, 60, 50);
[ret2 setTitle:@"Return" forState:UIControlStateNormal];
[ret2 addTarget:self action:@selector(flipAction:) forControlEvents:UIControlEventTouchUpInside];
[scroll addSubview:ret2];

When I did that, the button simply disappeared off my screen. So How do I do this correctly? Thank you for your help!

回答1:

Instead of:

UIScrollView *scroll = [UIScrollView alloc];

do this (setting the frame to however big you want the scroll view to be):

UIScrollView *scroll = [[UIScrollView alloc] initWithFrame:...];

回答2:

This may be helpful to you for creating the uiscrollview programmatically
http://unconditionalloop.blogspot.com/2011/04/uiscrollview-programmatically.html

  UIScrollView *scrollview = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];   
     NSInteger viewcount= 4;  
     for(int i = 0; i< viewcount; i++) { 

        CGFloat y = i * self.view.frame.size.height;  
        UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, y,self.view.frame.size.width, self .view.frame.size.height)];       
        view.backgroundColor = [UIColor greenColor];  
        [scrollview addSubview:view];  
        [view release];  
     }    
  scrollview.contentSize = CGSizeMake(self.view.frame.size.width, self.view.frame.size.height *viewcount);   
  [self.view addSubview:scrollview];

回答3:

try this,

{

        scrollview=[[UIScrollView alloc]initWithFrame:CGRectMake(0,0,320,480)]; 
        scrollview.showsVerticalScrollIndicator=YES;
        scrollview.scrollEnabled=YES;
        scrollview.userInteractionEnabled=YES;
        [self.view addSubview:scrollview];
        scrollview.contentSize = CGSizeMake(width,height);

    [scrollview release];
}

回答4:

Create a UiScrollView Programitically

ScrView = [[UIScrollView alloc]initWithFrame:CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y, self.view.frame.size.width, self.view.frame.size.height)];
ScrView.showsVerticalScrollIndicator=YES;
[ScrView setBackgroundColor:[UIColor yellowColor]];
[ScrView setScrollEnabled:YES];
[ScrView setContentSize:CGSizeMake(0, 700)];
[ScrView setShowsHorizontalScrollIndicator:YES];
[ScrView setShowsVerticalScrollIndicator:YES];
[self.view addSubview:ScrView];

回答5:

I use lazy a lot when creating UI programmatically, like this:

class WorldViewController: UIViewController {
    override func loadView() {
        super.loadView()
        view = scrollView
        scrollView.addSubview(label0)
    }

    lazy var scrollView: UIScrollView = {
        let instance = UIScrollView()
        instance.backgroundColor = UIColor.blackColor()
        return instance
    }()

    lazy var label0: UILabel = {
        let instance = UILabel()
        instance.text = "Ice caps are melting"
        instance.textColor = UIColor.whiteColor()
        instance.sizeToFit()
        return instance
    }()

    var needLayoutContent = true

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        if needLayoutContent {
            let bounds = scrollView.bounds
            let contentSize = CGSizeMake(bounds.width * 1.5, bounds.height * 1.5)
            label0.center = CGPointMake(contentSize.width / 2, contentSize.height / 2)
            scrollView.contentSize = contentSize
            scrollView.contentOffset = CGPointMake(bounds.width * 0.25, bounds.height * 0.25)
            needLayoutContent = false
        }
    }
}

回答6:

Simple Method: You can create multiple times if you need more

- (void)viewDidLoad
{
    [super viewDidLoad];

    int x = 0;
    int y = 10;
    for(int i=0; i<5; i++)
    {
        UIScrollView *scrollview=[[UIScrollView alloc]initWithFrame:CGRectMake(x, y, 50, 50)];
        scrollview.showsVerticalScrollIndicator=YES;
        scrollview.scrollEnabled=YES;
        scrollview.userInteractionEnabled=YES;
        scrollview.backgroundColor = [UIColor greenColor];
        [self.view addSubview:scrollview];
        //scrollview.contentSize = CGSizeMake(50,50);
        x=x+55;

        //[self myscrollView];
    }
}

回答7:

Calculate distance between 2 point on maps for iOS [closed]

import UIKit import CoreLocation

class ViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
    var myLocation = CLLocation(latitude: 23.1929, longitude: 72.6156)
    var myBuddysLocation = CLLocation(latitude: 23.0504, longitude: 72.4991)
    var distance = myLocation.distance(from: myBuddysLocation) / 1000
    print(String(format: "The distance to my buddy is %.01fkm", distance))
}

}