UITextView的一些使用技巧

NSMutableString *TextViewStr=[[NSMutableString alloc] initWithString:TextView.text];
        [TextViewStr insertString:@"your strings" atIndex:TextView.selectedRange.location];
        TextView.scrollEnabled=NO;
        TextView.text=theTvStr;
         theTV.scrollEnabled=YES;

2.獲得行數（包括換行符也會計算在內）：

CGSize size = [[self.TextView text] sizeWithFont:[self.TextView font]];

   // 2. 取出文字的高度
    int length = size.height;

    //3. 計算行數
    int colomNumber = TextView.contentSize.height/length;

3.檢測換行符：

- (BOOL)textView: (UITextView *)textview shouldChangeTextInRange: (NSRange)range replacementText: (NSString *)text {
    if ([text isEqualToString:@"\n"]) {
        NSLog(@"it is a row !!");
        //...
    }
    return YES;
}<pre name="code" class="objc"> self.textView = [[[UITextView  alloc] initWithFrame:self.view.frame] autorelease]; //初始化大小并自動釋放

 self.textView.textColor = [UIColor blackColor];//設置textview里面的字體顏色 

 self.textView.font = [UIFont fontWithName:@"Arial" size:18.0];//設置字體名字和字體大小 

 self.textView.delegate = self;//設置它的委托方法 

 self.textView.backgroundColor = [UIColor whiteColor];//設置它的背景顏色

 self.textView.text = @"Now is the time for all good developers to come to serve their country.\n\nNow is the time for all good developers to come to serve their country.";//設置它顯示的內容 

 self.textView.returnKeyType = UIReturnKeyDefault;//返回鍵的類型 

 self.textView.keyboardType = UIKeyboardTypeDefault;//鍵盤類型 

 self.textView.scrollEnabled = YES;//是否可以拖動 

 self.textView.autoresizingMask = UIViewAutoresizingFlexibleHeight;//自適應高度

 [self.view addSubview: self.textView];//加入到整個頁面中

注釋：

文本字段實現了 UITextInputTrait協議，其提供了7個屬性來定義字段處理文本輸入的方式：autocapitalizationType、 autocorrectionType、enablesReturnKeyAutomatically、keyboardAppearance、 keyboardType、returnKeyType、secureTextEntry。其它，當文本字段為空時，placeholder文本以淺灰色顯示，提供一個用戶提示。通過設置clearButtonMode可以指定是否以及何時顯示清除按鈕。

#pragma mark - UITextView Delegate Methods 

-(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{ 
    if ([text isEqualToString:@"\n"]) { 

    [textView resignFirstResponder]; 

        return NO; 
    }

    return YES; 
}