Question

我在每个地方都搜索过这个问题，但我没有得到我的结果。我已将textview设置为委托。我想在标签＆＃34;计数器＆＃34;中显示计数。谁能告诉我我的代码有什么问题？

- (void)textViewDidChange:(UITextView *)textView
{  
    NSString *substring = [NSString stringWithString:textView.text];
    //if message has text show label and update with number of characters using the NSString.length function
    if (substring.length > 0) {
           self.counter.hidden = NO;
        self.counter.text= [NSString stringWithFormat:@"%d characters", substring.length];   
    }
    //if message has no text hide label
    if (substring.length == 0) {
        self.counter.hidden = YES;
    self.counter.text= [NSString stringWithFormat:@"%d characters", substring.length];
    }
}

Answer 1

使用此委托方法

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
    NSUInteger strLength = (textView.text.length - range.length) + text.length;
    return YES;
}

Answer 2

您的代码只是隐藏了标签，但在第一个字符到达时从未显示过。

而不是：

if (substring.length == 0) {
    self.counter.hidden = YES;

...始终设置可见性：

self.counter.hidden = substring.length == 0;

使用ios中的textViewDidChange计算字符数

2 个答案: