Question

我想删除返回键输入的换行符。但是，当我执行以下操作时，它会删除文本中的最后一个字符。为什么呢？

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text;
{
    NSLog(@"%d  %d  %@ %@",range.location,range.length, text, [textView text]);

    if ( [text isEqualToString:@"\n"] ) {

        NSString *s = [textView text];
        s = [s substringToIndex:[s length] - 1]; // <------------

        [tvText setText:[NSString stringWithFormat:@"%@\n>>",s]];
    }
    return YES;
}

我希望结果如下：

>>name
>>yoda
>>                <---- cursor is moved to the right of ">>"

Answer 1

我认为你可以做这样的事情，

    - (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text;
{
    NSLog(@"%d  %d  %@ %@",range.location,range.length, text, [textView text]);

    if ( [text isEqualToString:@"\n"] ) {

        [tvText setText:[NSString stringWithFormat:@"%@\n>>",tvText.text]];
        return NO;
    }
    return YES;
}

Answer 2

或者也许在你读完字符串之后把它放到一些子字符串中：

string = [string stringByReplacingOccurrencesOfString:@"\n;" withString:@""];

Answer 3

shouldChangeTextInRange是UITextViewDelegate的一部分，在之前被称为，在textView中更改了新文本。因此，您可以这样做：

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text; { if ([text isEqualToString:@"\n"]) { return NO; } return YES; }

Answer 4

使用此功能可获得更好的解决方案，因为它不会允许用户在任何情况下发布任何空白消息。

//These for loops will remove the spaces and new line characters from start and end of the string

    //&&//

    NSMutableString *temp = [[NSMutableString alloc] initWithString:posttextview.text];

    //Remove spaces and new line characters from start
    for(int i = 0; i < yourtext.length; i++)
    {
        NSString *temp1 = [NSMutableString stringWithString:[temp substringWithRange:NSMakeRange(0,1)]];

        if([temp1 isEqualToString:@"\n"] || [temp1 isEqualToString:@" "])
        {
            [temp deleteCharactersInRange:NSMakeRange(0,1)];
        }

        else
        {
            break;
        }
    }

    yourtext.text = temp;

    //Remove spaces and new line characters from end
    for(int i = 0; i < yourtext.length; i++)
    {
        NSString *temp1 = [NSMutableString stringWithString:[temp substringWithRange:NSMakeRange(posttextview.text.length - 1,1)]];

        if([temp1 isEqualToString:@"\n"] || [temp1 isEqualToString:@" "])
        {
            [temp deleteCharactersInRange:NSMakeRange(posttextview.text.length - 1,1)];

            yourtext.text = temp;
        }

        else
        {
            break;
        }
    }

    yourtext.text = temp;

    //**//

Answer 5

问题是时间shouldChangeCharactersImRange被调用，新文本实际上还没有改变（这就是为什么它没有命名为didChangeCharactersInRange ...）。因此，如果您遇到换行符，请不要使用子字符串进行操作，只需存储/处理文本视图到目前为止包含的字符串，然后返回NO。

Answer 6

首先在.h文件中添加UITextViewDelegate

@interface YourClass : UITextField <UITextFieldDelegate> {
}

然后实现委托方法

-(BOOL)shouldChangeCharactersInRange:replacementString:

UITextView，如何删除返回键：linefeed？

6 个答案: