Question

我使用了两种delegate方法为textView创建占位符。

代码：

-(BOOL)textViewShouldBeginEditing:(UITextView *)textView
{

    if([Description.text isEqualToString:@"Description of home"]&&[Description.font isEqual:[UIFont fontWithName:@"Helvetica" size:18]])
    {
        Description.text=nil;
    }
    if([Display.text isEqualToString:@"Display"]&&[Display.font isEqual:[UIFont fontWithName:@"Helvetica" size:18]])
    {
        Display.text=nil;
    }
    return YES;
}
-(BOOL)textViewShouldEndEditing:(UITextView *)textView
{

    if ([Description.text isEqualToString:@""]) // Description is textViewObject
    {
        Description.text=@"Description of home";
        Description.font=[UIFont fontWithName:@"Helvetica" size:18];
    }


    if ([Display.text isEqualToString:@""])
    {
        Display.text=@"Display";   // Display is textViewObject
        Display.font=[UIFont fontWithName:@"Helvetica" size:18];
    }
    return YES;
}
@end

这是正确的。但是问题是当我点击任何textView时，文本从所有textView获得nil。这是因为我已将所有textView连接到委托。

我希望该文本仅在特定的textView上消失。

Answer 1

您可以在委托方法中添加条件，如下所示：

-(BOOL)textViewShouldBeginEditing:(UITextView *)textView
{
if(textView == yourTextView1)
{
    //your code for perticular textView1
}
 else if(textView == yourTextView2)
{
    //your code for perticular textView2
}

  return YES;
}

Answer 2

您需要以某种方式区分每个UITextViews。

如果您要在屏幕上显示少量UITextViews，则应将每个UItextView保存为属性。在creating IBOutlets

上查看此YouTube视频

然后按顺序命名UITextViews：textView1，textView2等......

然后在您的委托方法中，您可以检查方法中传递的textView是否等于要从中删除文本的属性。

if (textView == self.textView1) {
    //delete text
} else {
    //do nothing or something else
}

Answer 3

检查代表是否在想要的UITextView上运行：

-(BOOL)textViewShouldBeginEditing:(UITextView *)textView
{

    if(textView == Description && [Description.text isEqualToString:@"Description of home"]&&[Description.font isEqual:[UIFont fontWithName:@"Helvetica" size:18]])
    {
        Description.text=nil;
    }
    if(textView==Display && [Display.text isEqualToString:@"Display"]&&[Display.font isEqual:[UIFont fontWithName:@"Helvetica" size:18]])
    {
        Display.text=nil;
    }
    return YES;
}

Answer 4

@最简单的解决方案这个问题的CmKndy是https://stackoverflow.com/a/10201671/3633534

在您的班级中使用UITextViewDelegate委托，并在@"placeholder text here..."中添加textView文字，lightGrayColor默认显示。

以下代码适用于textView中的占位符：

- (void)textViewDidBeginEditing:(UITextView *)textView
{
    if ([textView.text isEqualToString:@"placeholder text here..."]) {
        textView.text = @"";
        textView.textColor = [UIColor blackColor]; //optional
    }
    [textView becomeFirstResponder];
}

- (void)textViewDidEndEditing:(UITextView *)textView
{
    if ([textView.text isEqualToString:@""]) {
        textView.text = @"placeholder text here...";
        textView.textColor = [UIColor lightGrayColor]; //optional
    }
    [textView resignFirstResponder];
}

针对您的问题[更新]

-(BOOL)textViewShouldBeginEditing:(UITextView *)textView
{
    if(textView == Description && [Description.text isEqualToString:@"Description of home"])
    {
        Description.text = @"";
    }
    else if(textView == Display && [Display.text isEqualToString:@"Display"])
    {
        Display.text = @"";
    }
    return YES;
}

-(BOOL)textViewShouldEndEditing:(UITextView *)textView
{
    if (textView == Description && [Description.text isEqualToString:@""]) // Description is textViewObject
    {
        Description.text = @"Description of home";
        Description.font=[UIFont fontWithName:@"Helvetica" size:18];
    }
    else if (textView == Display && [Display.text isEqualToString:@""])
    {
        Display.text = @"Display";   // Display is textViewObject
        Display.font=[UIFont fontWithName:@"Helvetica" size:18];
    }
    return YES;
}
@end

textView中占位符的替代方案

4 个答案: