如何在 iOS 中删除 UITextfield 并从中输入数据

Question

我开发了一个应用程序，其中我有两个名为 [+] 和 [-] 的 UIButton 和一个 UITextField 默认值。

现在我想要的是，当我单击加号 [+] 按钮时，它应该在 UIView 中添加一个 UITextField，这对我来说非常有用，但是当我单击减号时 [-]按钮，它应该删除最后创建的 UITextField，它现在对我不起作用。

如何管理？

这是我加号[+]按钮的代码。

- (IBAction)btnPlusClicked:(id)sender { scrollViewSpecialitiesTxtFields.hidden = FALSE; 浮动y; y = (35 * txtSpecialityFieldCounter); UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(0, y, 120, 30)]; textField.delegate = self; textField.borderStyle = UITextBorderStyleRoundedRect; [arraySpecialitiesTxtFields insertObject:textField atIndex:arraySpecialitiesTxtFields.count]; scrollViewSpecialitiesTxtFields.contentSize = CGSizeMake(125, y+30); [scrollViewSpecialitiesTxtFields addSubview:textField]; txtSpecialityFieldCounter++; NSLog(@"txtSpecialityFieldCounter : %d",txtSpecialityFieldCounter); }

这是我的减号 [-] 按钮代码

-(IBAction)btnMinusClicked:(id)sender
{
    [scrollViewSpecialitiesTxtFields.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];

    txtSpecialityFieldCounter--;
    NSLog(@"txtSpecialityFieldCounter : %d",txtSpecialityFieldCounter);

    float y;

    y = (35 * txtSpecialityFieldCounter);

    for(int i = 0 ; i < txtSpecialityFieldCounter; i++)
    {
        UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(0, y, 120, 30)];
        textField.delegate = self;
        textField.borderStyle = UITextBorderStyleRoundedRect;

        [arraySpecialitiesTxtFields insertObject:textField atIndex:arraySpecialitiesTxtFields.count];

        scrollViewSpecialitiesTxtFields.contentSize = CGSizeMake(125, y-30);
        [scrollViewSpecialitiesTxtFields addSubview:textField];
    }
}

我知道减号 [-] 按钮代码有误，但请告诉我更改

Answer 1

在NSMutableArray *myAddedTextfields 和viewDidLoad-> myAddedTextFields = [NSMutableArray array]; 中创建一个全局变量

- (IBAction)plusAction:(id)sender 
{
UITextField *textField1 = [[UITextField alloc]initWithFrame:CGRectMake(50, 50, 100, 20)];

textField1.text = @"hey how r u";

textField1.backgroundColor = [UIColor grayColor];

textField1.tag = 1;
[self.view addSubview:textField1];
[myAddedTextFields addObject:textField1];
}

- (IBAction)minusAction:(id)sender 
{
UITextField *txtField = [myAddedTextFields objectAtIndex:myAddedTextFields.count -1]; //for deleting from the last textfield onwards.

[txtField removeFromSuperView];
[myAddedTextFields removeObjectIdenticalTo:txtField];

}

我已经编辑了你的方法..希望这会有所帮助。

Answer 2

每当您想在超级视图上添加UITextField 时，请设置该组件的标签 (UITextField)。

当你想从超级视图中删除它时，然后使用标签获取该组件的引用 (UITextField) 并将其从超级视图中删除。

下面是一个可能对你有帮助的例子：

-(IBAction)plusAction:(id)sender 
{
    UITextField *textField1 = [[UITextField alloc]initWithFrame:CGRectMake(50, 50, 100, 20)];

    textField1.text = @"hey how r u";

    textField1.backgroundColor = [UIColor grayColor];

    textField1.tag = 1;
    [self.view addSubview:textField1];
}

-(IBAction)minusAction:(id)sender 
{
    UITextField * textfield = (UITextField *)[self.view viewWithTag:1];
    [textfield removeFromSuperview];
}

Answer 3

是的，您可以使用标签选项。或者您可以使用NSArray 来保存您的UITextFields。

@interface MyTextFieldViewClass ()

@property (nonatomic, retain) NSMutableArray *textFields;

@end

@implementation MyTextFieldViewClass

- (void)viewDidLoad {
    [super viewDidLoad];

    self.textFields = [NSMutableArray array];
}

- (IBAction)addTextField:(id)sender {
    UITextField *tf = [[UITextField alloc] initWithFrame:CGRectMake(50, 50, 100, 20)];

    [self.textFields addObject:tf];
    [self.view addSubview:tf];
}

- (IBAction)removeTextField:(id)sender {
    UITextField *tf = [self.textFields lastObject];
    [tf removeFromSuperview];

    [self.textFields removeLastObject];
}

@end

这会更好一些，因为您不必遍历 self.view.subviews 中存在的所有视图/ID。此外，使用tag 可能不可靠，因为您总是想删除最后一项，因此您需要将最后一项编号保留在内存中，或者您需要遍历所有子视图才能找到@987654325 @ 带有最高标签并删除它。