如何根据ios中的UITextView内容大小滚动scrollview

我在

UIViewController

上添加了一个滚动视图，并且在该滚动视图上添加了内容视图

之后，我在内容视图中添加了一个textview，textdata来自服务

这里我的主要要求是滚动内容大小需要根据文本数据大小设置，但根据我的代码contentview滚动太多，但我必须根据文本数据大小滚动contentview，请帮助我

显然，这种

UITextView

行为，即

UITextView

正在向上滚动文本数据内容大小

我的代码：-

    #import "ViewController.h"

    @interface ViewController ()

    {
        UITextView * TextView;

        UIScrollView * scrollView;
        UIView * containerView;
    }

    @end

    @implementation ViewController

    - (void)viewDidLoad
    {
        [super viewDidLoad];

        scrollView = [[UIScrollView alloc] init];
        scrollView.backgroundColor = [UIColor redColor];
        scrollView.translatesAutoresizingMaskIntoConstraints = NO;
        [self.view addSubview:scrollView];

        containerView = [[UIView alloc] init];
        containerView.backgroundColor = [UIColor whiteColor];
        containerView.translatesAutoresizingMaskIntoConstraints = NO;
        [scrollView addSubview:containerView];

        NSDictionary * views = NSDictionaryOfVariableBindings(scrollView,containerView);

        [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[scrollView]|" options:0 metrics:nil views:views]];

        [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[scrollView(600)]|" options:0 metrics:nil views:views]];

        TextView = [[UITextView alloc]init];
        TextView.translatesAutoresizingMaskIntoConstraints = NO;
        TextView.text = 
    //Applying autolayouts for textview1
        NSLayoutConstraint * constraint2 = [NSLayoutConstraint constraintWithItem:TextView attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem: containerView attribute:NSLayoutAttributeTop multiplier:1.0f constant:20.0f];
        [containerView addConstraint:constraint2];

        constraint2 = [NSLayoutConstraint constraintWithItem:TextView attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:containerView attribute:NSLayoutAttributeLeading multiplier:1.0f constant:5.0f];
        [containerView addConstraint:constraint2];

        constraint2 = [NSLayoutConstraint constraintWithItem:TextView attribute:NSLayoutAttributeTrailing relatedBy:NSLayoutRelationEqual toItem:containerView attribute:NSLayoutAttributeTrailing multiplier:1.0f constant:-5.0f];
        [containerView addConstraint:constraint2];

        constraint2 = [NSLayoutConstraint constraintWithItem:TextView attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1.0f constant:1000];
        [containerView addConstraint:constraint2];


 [scrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[containerView(==scrollView)]|"
                                                                           options:0
                                                                           metrics:nil
                                                                             views:views]];

        [scrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[containerView(1200)]|"
                                                                           options:0
                                                                           metrics:nil
                                                                             views:views]];
    }