NSMutableArray of UIViews

Question

在这个小应用程序中，我只想做一个问卷，在UIView上显示每个问题。由于问题单的大小可能会根据我的需要而变化，所以我希望通过使用for循环和NSMutableArray来操作这些UIViews，使代码变得非常灵活。我已经用下面的代码创建了数组和视图，但是除了紫色的UIScrollView之外，什么都没有显示。有人能指出为什么绿色UIViews没有出现吗？

ViewController.h

@interface ViewController : UIViewController

@property (nonatomic, strong) NSMutableArray *viewArray;
@property UIView *question1View;
@property UIView *question2View;
@property UIView *question3View;

@property UIScrollView *questionScrollView;

ViewController.m

@implementation ViewController

@synthesize viewArray;

float viewHeight = 75.0;
float openViewHeight = 225.0;
float currentViewPossitionX = 0.0;
float currentViewPossitionY = 0.0;
float viewSpacing = 10.0;
int numberOfQuestions = 3;

- (void)viewDidLoad {
    [super viewDidLoad];
    [self setUpQuestionnaire];

}


- (void) setUpQuestionnaire{

    self.viewArray[numberOfQuestions] = [[NSMutableArray alloc] init];
    [viewArray insertObject: _question1View atIndex:0];
    [viewArray insertObject: _question2View atIndex:1];
    [viewArray insertObject: _question3View atIndex:2];

    _question1View.backgroundColor = [UIColor greenColor];
    _question2View.backgroundColor = [UIColor greenColor];
    _question3View.backgroundColor = [UIColor greenColor];

    float viewCount = 0;

    _questionScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 100, CGRectGetWidth(self.view.bounds), CGRectGetHeight(self.view.bounds))];
    _questionScrollView.backgroundColor = [UIColor purpleColor];
    _questionScrollView.contentSize = CGSizeMake(CGRectGetWidth(self.view.bounds),(CGRectGetHeight(self.view.bounds)+100));
    [self.view addSubview:_questionScrollView];

    for(int i = 0; i < numberOfQuestions; i++){
        viewArray[i] = [[UIView alloc] initWithFrame:CGRectMake(currentViewPossitionX, currentViewPossitionY, CGRectGetWidth(_questionScrollView.bounds), viewHeight)];

        [_questionScrollView addSubview:viewArray[i]];
        viewCount++;
        currentViewPossitionY += viewHeight + viewSpacing;
    }

    _questionScrollView.contentSize = CGSizeMake(CGRectGetWidth(self.view.bounds),(viewHeight * viewCount + 500));



}

Answer 1

如果将数组init更改为以下内容，

self.viewArray = [[NSMutableArray alloc] init];

在将视图添加到数组之前初始化视图，

_question1View = [[UIView alloc] init];
_question2View = [[UIView alloc] init];
_question3View = [[UIView alloc] init];
[viewArray insertObject: _question1View atIndex:0];
[viewArray insertObject: _question2View atIndex:1];
[viewArray insertObject: _question3View atIndex:2];

最后，只要在循环中设置框架，

for(int i = 0; i < numberOfQuestions; i++) {
    UIView *view = viewArray[i];
    view.frame = CGRectMake(currentViewPossitionX, currentViewPossitionY, CGRectGetWidth(_questionScrollView.bounds), viewHeight);
....

在这些更改之后，它应该可以工作。

Answer 2

for(int i = 0; i < numberOfQuestions; i++){
    UIView *aview=viewArray[i];
    aview = [[UIView alloc] initWithFrame:CGRectMake(currentViewPossitionX, currentViewPossitionY, CGRectGetWidth(_questionScrollView.bounds), viewHeight)];
    aview.backgroundColor = [UIColor greenColor];
    [_questionScrollView addSubview:aview];
    viewCount++;
    currentViewPossitionY += viewHeight + viewSpacing;
}

Answer 3

我认为您应该使用自定义UITableViewCell来实现这一点。优点是-容易定制-不需要管理框架大小，因为表视图有自己的滚动视图-为您的所有问题创建模型数组，并只需在UITableView上迭代它

如果您想以列表的方式显示相同类型的UI (数据将按项目位置更改)，请选择tableview。