如何修復UITextView的文本長度？

Question

我有一個UITextView，用戶可以在textView中寫入最多160個字符。 我如何解決UITextView的最大文本長度？

Answer 1

更換

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string 

與

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text 

這是回答here

Answer 2

你可以看到類似的問題here。它已得到了答案

Answer 3

這個代碼塊還與複製/粘貼，而且還與形勢時科佩斯試圖粘貼會使文本視圖超出限制的字符數。在這種情況下，只有字符串的第一個字符被粘貼。

#define MAX_LENGTH 15 // Whatever your limit is 
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text 
{ 
    NSUInteger newLength = (textView.text.length - range.length) + text.length; 
    if(newLength <= MAX_LENGTH) 
    { 
     return YES; 
    } else { 
     NSUInteger emptySpace = MAX_LENGTH - (textView.text.length - range.length); 
     textView.text = [[[textView.text substringToIndex:range.location] 
              stringByAppendingString:[text substringToIndex:emptySpace]] 
             stringByAppendingString:[textView.text substringFromIndex:(range.location + range.length)]]; 
     return NO; 
    } 
} 

Answer 4

這個答案遲到了; manicaesar的解決方案對我無效。下面是我執行同樣的想法的：

#define MAX_LENGTH 140 
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)replacementText 
{ 
    NSString *newText = [ textView.text stringByReplacingCharactersInRange: range withString: replacementText ]; 
    if([newText length]<= MAX_LENGTH){ 
     return YES; 
    } 
    // case where text length > MAX_LENGTH 
    textView.text = [ newText substringToIndex: MAX_LENGTH ]; 
    return NO; 
} 

Answer 5

斯威夫特3

fileprivate let maxLen = 5 

    extension MyViewController : UITextViewDelegate{ 
     func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool { 

      let newLen = (textView.text.characters.count - range.length) + text.characters.count 
      return newLen <= maxLen 
     } 

    }