keyboad

1. typedef enum {  
2.     UIKeyboardTypeDefault,                // 默认键盘：支持所有字符   
3.     UIKeyboardTypeASCIICapable,           // 支持ASCII的默认键盘   
4.     UIKeyboardTypeNumbersAndPunctuation,  // 标准电话键盘，支持+*#等符号   
5.     UIKeyboardTypeURL,                    // URL键盘，有.com按钮；只支持URL字符   
6.     UIKeyboardTypeNumberPad,              //数字键盘   
7.     UIKeyboardTypePhonePad,               // 电话键盘   
8.     UIKeyboardTypeNamePhonePad,           // 电话键盘，也支持输入人名字   
9.     UIKeyboardTypeEmailAddress,           // 用于输入电子邮件地址的键盘   
10. } UIKeyboardType;  

1. typedef enum {  
2.     UIKeyboardAppearanceDefault,    // 默认外观：浅灰色   
3.     UIKeyboardAppearanceAlert,      //深灰/石墨色   
4. } UIKeyboardAppearance;  

1. typedef enum {  
2.     UITextAutocapitalizationTypeNone, //不自动大写   
3.     UITextAutocapitalizationTypeWords, //单词首字母大写   
4.     UITextAutocapitalizationTypeSentences, //句子首字母大写   
5.     UITextAutocapitalizationTypeAllCharacters, //所有字母大写   
6. } UITextAutocapitalizationType;  

1. typedef enum {  
2.     UITextAutocorrectionTypeDefault,//默认   
3.     UITextAutocorrectionTypeNo,//不自动更正   
4.     UITextAutocorrectionTypeYes,//自动更正   
5. } UITextAutocorrectionType;  

- (void)textViewDidChange:(UITextView *)textView
{
    int count = [textView.text length];
    //这里的count就是字符个数了}

-(IBAction)valuechange//m_TextField是UITextField的一个IBOutlet{
     int count = [m_TextField.text length];
     //count就是当前的字符个数

    //下边是将字符限制在140以内    if ([m_TextField.text length]>140) {
        [m_TextField setText:[m_TextField.text substringToIndex:140]];//多出140时，只取前140个字符    }
}

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
    if (1 == range.length) {//按下回格键        return YES;
    }
    if ([text isEqualToString:@"\n"]) {//按下return键
        //这里隐藏键盘，不做任何处理        [textView resignFirstResponder];
        return NO;
    }else {
        if ([textView.text length] < 140) {//判断字符个数            return YES;
        }  
    }
    return NO;
}