ios objective c 中的 TextView 占位符

Question

我在 iOS 应用程序中使用 textview，但是当我在我的 textview 中设置占位符时，我遇到了一些问题，当我在 textview 中单击时，文本不会隐藏，所以任何在 textview 中使用占位符的人都可以

Answer 1

您可以使用 textView 委托方法以编程方式管理占位符文本

- (void)textViewDidBeginEditing:(UITextView *)textView
{
    if ([textView.text isEqualToString:@"myPlaceHolderText"])       
    {
     textView.text = @"";
    }
    [textView becomeFirstResponder];
}

- (void)textViewDidEndEditing:(UITextView *)textView
{
    if ([textView.text isEqualToString:@""]) {
        textView.text = @"myPlaceHolderText";
    }
    [textView resignFirstResponder];
}

Answer 2

注意：在像文本字段这样的文本视图中，没有任何用于占位符的内置函数。

在 .h 文件中为您的 textView 创建一个 IBOutlet，如下所示

并像下面那样添加 <UITextViewDelegate>

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<UITextViewDelegate>
@property (weak, nonatomic) IBOutlet UITextView *mytextView;


@end

然后在您的 .m 文件中，实现 textview delegate 方法，如下所示。

如果你想要一些补充，也可以尝试使用上面的代码

- (void)textViewDidChange:(UITextView *)textView
{
    NSString *mtvt = textView.text;
    if ([mtvt isEqualToString:@""]) {
        self.mytextView.text = @"Your message here";
    }

}

Answer 3

Try This

1.Create 一个标签并显示或隐藏

-(void)viewdidLoad
{
   UILabel*placeHolderLabel = [UILabel alloc]initWithFrame:CGRectMake(0,0,300,30)];
   placeHolderLabel.text = @"PlaceHolderText";
   placeHolderLabel.textColour = [UIColour lightGrayColor]; 
   [yourTextView addSubView:placeHolderLabel];
}

//2.TextViewDelegate

- (void)textViewDidBeginEditing:(UITextView *)textView
{
    placeHolderLabel.hidden = YES;
    [textView becomeFirstResponder];
}

- (void)textViewDidEndEditing:(UITextView *)textView
{
    if ([textView.text isEqualToString:@""]) {
        placeHolderLabel.hidden = NO;
    }
    [textView resignFirstResponder];
}

Answer 4

无法在 UITextView 中创建占位符，但您可以通过此生成类似占位符的效果。

- (void)viewDidLoad{
    commentTxtView.text = @"Comment";
    commentTxtView.textColor = [UIColor lightGrayColor];
    commentTxtView.delegate = self;
}

- (BOOL) textViewShouldBeginEditing:(UITextView *)textView
{
    commentTxtView.text = @"";
    commentTxtView.textColor = [UIColor blackColor];
    return YES;
}

-(void) textViewDidChange:(UITextView *)textView
{
    if(commentTxtView.text.length == 0){
        commentTxtView.textColor = [UIColor lightGrayColor];
        commentTxtView.text = @"Comment";
        [commentTxtView resignFirstResponder];
    }
}

-(void) textViewShouldEndEditing:(UITextView *)textView
{
    if(commentTxtView.text.length == 0){
        commentTxtView.textColor = [UIColor lightGrayColor];
        commentTxtView.text = @"Comment";
        [commentTxtView resignFirstResponder];
    }
}

或者您可以在文本视图中添加标签，就像

lbl = [[UILabel alloc] initWithFrame:CGRectMake(10.0, 0.0,textView.frame.size.width - 10.0, 34.0)];


[lbl setText:kDescriptionPlaceholder];
[lbl setBackgroundColor:[UIColor clearColor]];
[lbl setTextColor:[UIColor lightGrayColor]];
textView.delegate = self;

[textView addSubview:lbl];

并设置

- (void)textViewDidEndEditing:(UITextView *) textView
{
     if (![textView hasText]) {
         lbl.hidden = NO;
     }
}

- (void) textViewDidChange:(UITextView *)textView
{
    if(![textView hasText]) {
       lbl.hidden = NO;
    }
    else{
       lbl.hidden = YES;
    }  
}

ios objective c 中的 TextView 占位符

TextView Placeholder in ios objective c

iphone

objective-c

ios7