IOS开发（13）之UITextField控件

1 前言

UITextField用来接受用户输入的文本，在开发中十分常见，今天我们来学习一下该控件。

2 代码实例

ZYViewController.h：

#import <UIKit/UIKit.h>@interface ZYViewController : UIViewController@property (nonatomic,strong)UITextField *myTextField;@end

ZYViewController.m：

@synthesize myTextField;- (void)viewDidLoad{    [super viewDidLoad];// Do any additional setup after loading the view, typically from a nib.    self.view.backgroundColor = [UIColor whiteColor];    CGRect textFieldFrame = CGRectMake(0.0f, 0.0f, 200.0f, 31.0f);    self.myTextField = [[UITextField alloc] initWithFrame:textFieldFrame];//绘制控件模型    self.myTextField.borderStyle = UITextBorderStyleRoundedRect;//设置如何显示边框    self.myTextField.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;//设置纵向居中    self.myTextField.textAlignment = UITextAlignmentCenter;//设置水平居中    self.myTextField.text = @"Sir Archy Develop_Zhang";//设置输入框内容    self.myTextField.center = self.view.center;//设置UITextField位置    [self.view addSubview:self.myTextField];}

ZYUITextFieldViewController.h：

#import <UIKit/UIKit.h>@interface ZYUITextFieldViewController : UIViewController<UITextFieldDelegate>@property(nonatomic,strong) UITextField *myTextField;@property(nonatomic,strong) UILabel *labelCounter;@end

ZYUITextFieldViewController.m：

@synthesize myTextField;@synthesize labelCounter;- (void)viewDidLoad{    [super viewDidLoad];// Do any additional setup after loading the view.    self.view.backgroundColor = [UIColor whiteColor];    CGRect textFieldFrame = CGRectMake(38.0f, 30.0f, 220.0f, 31.0f);    self.myTextField = [[UITextField alloc] initWithFrame:textFieldFrame];    self.myTextField.delegate = self;    self.myTextField.borderStyle = UITextBorderStyleRoundedRect;    self.myTextField.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;//    self.myTextField.text = @"Sir Archy Developer_Zhang";    self.myTextField.placeholder = @"Enter text here......";//当UITextField里面没有字符的时候，默认显示的内容    [self.view addSubview:myTextField];        CGRect labelCounterFrame = self.myTextField.frame;    labelCounterFrame.origin.y += textFieldFrame.size.height+10;    self.labelCounter = [[UILabel alloc] initWithFrame:labelCounterFrame];    [self.view addSubview:labelCounter];    [self calculateAndDisplayTextFieldLengthWithText:self.myTextField.text];        UILabel *currencyLabel = [[UILabel alloc] initWithFrame:CGRectZero];//CGRectZero相当于CGRectMake(0,0,0,0)    currencyLabel.text = [[[NSNumberFormatter alloc] init] currencySymbol];//初始化Label内容返回接受者的本地货币符号    currencyLabel.font = self.myTextField.font;    [currencyLabel sizeToFit];//调整和移动接收者的视图,它只是包含它自己的视图。    self.myTextField.leftView = currencyLabel;    self.myTextField.leftViewMode = UITextFieldViewModeAlways;//设置左视图一直显示    /*     typedef enum{     UITextFieldViewModeNever,//从不显示     UITextFieldViewModeWhileEditing,//编辑时候显示     UITextFieldViewModeUnlessEditing,//编辑结束时候显示     UITextFieldViewModeAlways//一直显示     }UITextFieldViewMode;               */    }//计算UITextField里面字符的长度-(void)calculateAndDisplayTextFieldLengthWithText:(NSString *)paramText{    NSString *characterOrCharacters = @"Characters";    if ([paramText length]==1) {        characterOrCharacters = @"Character";    }    self.labelCounter.text = [NSString stringWithFormat:@"%lu %@",(unsigned long)[paramText length],characterOrCharacters];}//当UITextField输入文字后触发的事件-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{    BOOL result = YES;    if ([textField isEqual:self.myTextField]) {        NSString *wholeText = [textField.text stringByReplacingCharactersInRange:range withString:string];//追加后输入的字符串        [self calculateAndDisplayTextFieldLengthWithText:wholeText];//重新计算字符长度    }    return result;}//当单击返回按钮触发的事件-(BOOL)textFieldShouldReturn:(UITextField *)textField{    [textField resignFirstResponder];//关闭键盘    return YES;}

运行结果：

3 结语

以上就是UITextField的简单介绍，希望对大家有所帮助。

Demo实例下载：http://download.csdn.net/detail/u010013695/5294545