1.UITextField的初始化和设置  textField = [[UITextField alloc] initWithFrame:CGRectMake(120.0f, 80.0f, 150.0f, 30.0f)];   [textField setBorderStyle:UITextBorderStyleRoundedRect]; //外框类型 

  textField.placeholder = @"password"; //默认显示的字 

  textField.secureTextEntry = YES; //密码 

  textField.autocorrectionType = UITextAutocorrectionTypeNo;   textField.autocapitalizationType = UITextAutocapitalizationTypeNone;   textField.returnKeyType = UIReturnKeyDone;   textField.clearButtonMode = UITextFieldViewModeWhileEditing; //编辑时会出现个修改X 

  textField.delegate = self;2.要实现的Delegate方法,关闭键盘  - (BOOL)textFieldShouldReturn:(UITextField *)textField   {       [self.textField resignFirstResponder];       return YES;   } 3. 可以在UITextField使用下面方法，按return键返回-(IBAction) textFieldDone:(id) sender{ [textFieldName resignFirstResponder]; }链接TextField控件的"Did end on exit"最右侧加图片是以下代码,    UIImageView *imgv=[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"right.png"]];    text.rightView=imgv;    text.rightViewMode = UITextFieldViewModeAlways;    

如果是在最左侧加图片就换成:text.leftView=imgv;text.leftViewMode = UITextFieldViewModeAlways;    UITextField 继承自 UIControl,此类中有一个属性contentVerticalAlignment所以想让UITextField里面的text垂直居中可以这样写:text.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;查看函数的方法：按住command键双击进入函数声明按住alt键双击进入doc文档///文本框常用方法:如何用程序删除文本框中选中的文本[textView delete: nil];///如何限制文本框只能输入数字:建立NSNumberFormatter的子类，增加这个方法，将formatter链接至文本框。

- (BOOL) isPartialStringValid: (NSString **) partialStringPtr        proposedSelectedRange: (NSRangePointer) proposedSelRangePtr               originalString: (NSString *) origString        originalSelectedRange: (NSRange) origSelRange             errorDescription: (NSString **) error{    NSCharacterSet *nonDigits;    NSRange newStuff;    NSString *newStuffString;

    nonDigits = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];    newStuff = NSMakeRange(origSelRange.location,                           proposedSelRangePtr->location                           - origSelRange.location);    newStuffString = [*partialStringPtr substringWithRange: newStuff];

    if ([newStuffString rangeOfCharacterFromSet: nonDigits                                                                                             options: NSLiteralSearch].location != NSNotFound) {        *error = @"不是数字";        return (NO);    } else {        *error = nil;        return (YES);    }

}///从文本框获取十六进制数据的代码char singleNumberString[3] = {'\0','\0','\0'};uint32_t singleNumber = 0;uint32_t i = 0; NSMutableData *data = [NSMutableData data]; //从文本框获取到得数据 const char *buf = [[_hexToSendTextField text] UTF8String]; //转换为十六进制 for(i = 0; i < strlen(buf); i+=2) { if(((i+1) < len && isxdigit(buf) && (isxdigit(buf[i+1]))) { singleNumberString[0] = buf; singleNumberString[1] = buf[i+1]; sscanf(singleNumberString, "%x", &singleNumber); [data appendBytes:(void*)(&tmp) length:1]; } else { break; } } //输出 NSLog(@"%@", data);/点击 UITextView 输入文字，光标都从最初点开始- (void)textViewDidChangeSelection:(UITextView *)textView{    NSRange range;    range.location = 0;    range.length = 0;    textView.selectedRange = range;}///软键盘在登录页面要实现用户名和密码，密码要是点点格式，引入当前页面光标要停留在用户名选项，软键盘要弹出界面。如下图：弹出键盘：[username becomeFirstResponder];取消键盘：[username resignFirstResponder];密码保护：password.secureTextEntry=YES;//1.UITextField的初始化和设置  textField = [[UITextField alloc] initWithFrame:CGRectMake(120.0f, 80.0f, 150.0f, 30.0f)];   [textField setBorderStyle:UITextBorderStyleRoundedRect]; //外框类型   textField.placeholder = @"password"; //默认显示的字   textField.secureTextEntry = YES; //密码   textField.autocorrectionType = UITextAutocorrectionTypeNo;   textField.autocapitalizationType = UITextAutocapitalizationTypeNone;   textField.returnKeyType = UIReturnKeyDone;   textField.clearButtonMode = UITextFieldViewModeWhileEditing; //编辑时会出现个修改X   textField.delegate = self;2.要实现的Delegate方法,关闭键盘  - (BOOL)textFieldShouldReturn:(UITextField *)textField   {       [self.textField resignFirstResponder];       return YES;   } 3. 可以在UITextField使用下面方法，按return键返回-(IBAction) textFieldDone:(id) sender{ [textFieldName resignFirstResponder]; }链接TextField控件的"Did end on exit"

限制输入文本的长度- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{    if (range.location >= MAX_LENGTH)        return NO; // return NO to not change text    return YES;}if (textField.text.length >= 10 && range.length == 0)    return NO;return YES;- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {  if ([textField.text length] > MAXLENGTH)  {   textField.text = [textField.text substringToIndex:MAXLENGTH-1];   return NO;  }  return YES; } //使用UITextFieldDelegate来隐藏键盘 在iPhone界面上，时常会需要当用户输入完内容后，隐藏键盘。 当然有很多方法，今天只介绍使用UITextFieldDelegate这个协议实现隐藏键盘。其实很简单， 需要三步：1. 在你的控制器类中，加入UITextFieldDelegate这个协议如：@interface AddItemViewController : UIViewController <UITextFieldDelegate>2. 在使用了UITextFieldDelegate协议的控制器类的实现中，加入- (BOOL)textFieldShouldReturn:方法。- (BOOL)textFieldShouldReturn:(UITextField *)textField {

        [textField resignFirstResponder];        return YES;} //设置焦点：

[UITextField becomeFirstResponder];

3. 将xib文件中的TextField控件的delegate变量指向到之前使用UITextFieldDelegate协议的那个控制器类,将 TextField的delegate IBOutlet变量右键链接到前面的控制器类的实例上。或者使用代码方式，指定相关TextField的delegate变量。

- (void)viewDidLoad 

{

    [super viewDidLoad];

        itemNameField.delegate = self;

        priceField.delegate = self;

}