UI控件（UITextField）

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];

UITextField* textField1 = [[UITextField alloc] init];

//设置代理表示实现协议 UITextFieldDelegate
textField1.delegate = self;
textField1.frame = CGRectMake( 20, 120, 280, 30 );
//    边框样式
//    typedef enum {
//        UITextBorderStyleNone,            无边框
//        UITextBorderStyleLine,            直线边框
//        UITextBorderStyleBezel,           左边框、上边框加粗
//        UITextBorderStyleRoundedRect      圆角
//    } UITextBorderStyle;
textField1.borderStyle = UITextBorderStyleRoundedRect;
textField1.text = @"hello,textfield";
textField1.placeholder = @"please input the text";

//设置字体及大小
textField1.font = [UIFont fontWithName:@"Arial" size:10.0f];
//设置字体颜色
textField1.textColor = [UIColor blueColor];
//    typedef enum {
//        UITextFieldViewModeNever,             重不出现
//        UITextFieldViewModeWhileEditing,      编辑时出现
//        UITextFieldViewModeUnlessEditing,     除了编辑外都出现
//        UITextFieldViewModeAlways             一直出现
//    } UITextFieldViewMode;
textField1.clearButtonMode = UITextFieldViewModeAlways;

//采用星号加密显示
textField1.secureTextEntry = NO;

//定义弹出的软键盘类型
//UIKeyboardTypeDefault     默认全部
//UIKeyboardTypeNumberPad   数字键盘
//类型较多，此处省略
textField1.keyboardType = UIKeyboardTypeDefault;

//定义软键盘上的回车按键的样式
//    UIReturnKeyDefault,   默认 灰色按钮，标有Return
//    UIReturnKeyGo,        标有Go的蓝色按钮
//    类型较多此处省略
textField1.returnKeyType = UIReturnKeyDefault;

//左侧或右侧增加图片
UIImageView *image=[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"person.png"]];
textField1.leftView=image;
textField1.leftViewMode = UITextFieldViewModeAlways;

[self.view addSubview:textField1];
}

#pragma mark - TextField Delegates

//开始编辑时出发回调
-(void)textFieldDidBeginEditing:(UITextField *)textField{
NSLog(@"%s", __FUNCTION__);
}

//结束编辑时出发回调(软键盘消失)
-(void)textFieldDidEndEditing:(UITextField *)textField{
NSLog(@"%s", __FUNCTION__);
}

//回车时被回调
-(BOOL) textFieldShouldReturn:(UITextField *)textField{
NSLog(@"%s", __FUNCTION__);
[textField resignFirstResponder];//若该行注释则软件盘在回车后部消失
return YES;
}

@end