如何从父视图中删除子视图

Question

您好我是ios的初学者，我正在尝试以编程方式在我的父类上添加多个子视图，他们正在添加正常（这里我从后台类加载子视图）

但是当我在父视图类中添加第二个子视图时，我想删除我父视图类中的第一个子视图但是它不是删除我的代码，请在下面帮我一个

我的代码： -

子类： -

#import "MainView1.h"

@interface MainView1 ()

@end

@implementation MainView1

- (void)viewDidLoad {
    [super viewDidLoad];
}

-(void)loadView1 :(UIView *)myview :(int)viewValue :(UIViewController*)VC
{
    UIView * firstview;
    UIView * secondview;

    if (viewValue == 1) {

    [firstview willRemoveSubview:myview];
    [secondview willRemoveSubview:myview];

    firstview =[[UIView alloc]initWithFrame:CGRectMake(0, 50, 320, 430)];
    [firstview setBackgroundColor:[UIColor yellowColor]];
    UIButton *addProject=[[UIButton alloc]init];
    addProject = [UIButton buttonWithType: UIButtonTypeRoundedRect];
    addProject.frame = CGRectMake(100, 285, 100, 18);
    addProject.backgroundColor = [UIColor redColor];
    [addProject setTitle:@"Show View" forState:UIControlStateNormal];
    [addProject addTarget:VC action:@selector(ProjectPressed:) forControlEvents:UIControlEventTouchUpInside];
    [firstview addSubview:addProject];
    [myview addSubview:firstview];

    }

    else {

    [firstview willRemoveSubview:myview];
    [secondview willRemoveSubview:myview];

    secondview =[[UIView alloc]initWithFrame:CGRectMake(0, 50, 320, 400)];
    [secondview setBackgroundColor:[UIColor greenColor]];
    UIButton *addProject1=[[UIButton alloc]init];
    addProject1 = [UIButton buttonWithType: UIButtonTypeRoundedRect];
    addProject1.frame = CGRectMake(200, 285, 100, 18);
    addProject1.backgroundColor = [UIColor redColor];
    [addProject1 setTitle:@"Show View1" forState:UIControlStateNormal];
    [addProject1 addTarget:VC action:@selector(ProjectPressed123:) forControlEvents:UIControlEventTouchUpInside];
    [secondview addSubview:addProject1];
    [myview addSubview:secondview];

    }
}

父类： -

当我点击下面的ProjectPressed按钮操作时，我想在我的父视图类上添加第二个子视图，它添加正常但第一个子视图未从父视图类中删除

#import "ViewController.h"
#import "MainView1.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    MainView1 * m1 = [[MainView1 alloc]init];
    [m1 loadView1:self.view :1 :self];

}

- (void)ProjectPressed:(id)sender
{
    MainView1 * m1 = [[MainView1 alloc]init];
    [m1 loadView1:self.view :2 :self];
}

Answer 1

试试这个

[firstview removeFromSuperview]
[secondview removeFromSuperview]

Answer 2

请立即尝试

-(void)loadView1 :(UIView *)myview :(int)viewValue :(UIViewController*)VC
{
UIView * firstview;
UIView * secondview;

for (UIView *view in [myview subviews]) 
{
 [view removeFromSuperview];
}

if (viewValue == 1) {

firstview =[[UIView alloc]initWithFrame:CGRectMake(0, 50, 320, 430)];
[firstview setBackgroundColor:[UIColor yellowColor]];
UIButton *addProject=[[UIButton alloc]init];
addProject = [UIButton buttonWithType: UIButtonTypeRoundedRect];
addProject.frame = CGRectMake(100, 285, 100, 18);
addProject.backgroundColor = [UIColor redColor];
[addProject setTitle:@"Show View" forState:UIControlStateNormal];
[addProject addTarget:VC action:@selector(ProjectPressed:) forControlEvents:UIControlEventTouchUpInside];
[firstview addSubview:addProject];
[myview addSubview:firstview];

}

else {

secondview =[[UIView alloc]initWithFrame:CGRectMake(0, 50, 320, 400)];
[secondview setBackgroundColor:[UIColor greenColor]];
UIButton *addProject1=[[UIButton alloc]init];
addProject1 = [UIButton buttonWithType: UIButtonTypeRoundedRect];
addProject1.frame = CGRectMake(200, 285, 100, 18);
addProject1.backgroundColor = [UIColor redColor];
[addProject1 setTitle:@"Show View1" forState:UIControlStateNormal];
[addProject1 addTarget:VC action:@selector(ProjectPressed123:) forControlEvents:UIControlEventTouchUpInside];
[secondview addSubview:addProject1];
[myview addSubview:secondview];

}

}