iphone - 如何在UITextView中插入占位符？

Question

这个问题已经有答案了:

Placeholder in UITextView (63 个回答)

已关闭 10 年前。

有没有办法在 UITextView 中插入占位符类似于UITextField ？如果是，请向我发送任何链接或任何实现此功能的想法。

Answer 1

无法在 UITextView 中创建占位符，但可以通过它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 TextView 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;
    }  
}