UITextField，UILabel， UIButton，UIAlertview的簡單使用

//  Created by 妖精的尾巴 on 15-8-14.

//  Copyright (c) 2015年 妖精的尾巴. All rights reserved.

//

#import "ViewController.h"

@interface ViewController ()<UIAlertViewDelegate>

@property(nonatomic,strong)UITextField* textField;

@end

@implementation ViewController

- (void)viewDidLoad

{

    [super viewDidLoad];

    self.view.backgroundColor=[UIColor whiteColor];

    [self createLabel];

    [self createTextField];

    [self createButton];

}

-(void)createLabel

{

    UILabel* label=[[UILabel alloc]initWithFrame:CGRectMake(110, 80, 100, 50)];

    label.text=@"妖精的尾巴";

    label.textAlignment=NSTextAlignmentCenter;

    label.textColor=[UIColor blueColor];

    label.font=[UIFont systemFontOfSize:17];

    [self.view addSubview:label];

    

    UILabel* label2=[[UILabel alloc]initWithFrame:CGRectMake(30, 120, 80, 50)];

    label2.text=@"用戶名：";

    label2.textAlignment=NSTextAlignmentCenter;

    label2.textColor=[UIColor greenColor];

    label2.font=[UIFont systemFontOfSize:16];

    [self.view addSubview:label2];

}

-(void)createTextField

{

    self.textField=[[UITextField alloc]initWithFrame:CGRectMake(110, 120, 150, 35)];

    self.textField.borderStyle= UITextBorderStyleRoundedRect;

    self.textField.placeholder=@"請輸入用戶名";

    self.textField.font=[UIFont systemFontOfSize:16];

    [self.view addSubview:self.textField];

}

-(void)createButton

{

    UIButton* btn=[UIButton buttonWithType:UIButtonTypeRoundedRect];

    btn.layer.cornerRadius=10;

    btn.showsTouchWhenHighlighted=YES;

    btn.backgroundColor=[UIColor yellowColor];

    btn.frame=CGRectMake(110,180,120,50);

    [btn setTitle:@"認真你就贏了" forState:UIControlStateNormal];

    [btn setTitleColor:[UIColor redColor] forState:UIControlStateNormal];

    [btn addTarget:self action:@selector(btnClick) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:btn];

}

-(void)btnClick

{

    /**

     *對UITextField調出鍵盤的退出處理方式有兩種

     *

     *第一種 在按鈕點擊方法中執行[self.textField resignFirstResponder];

     *

     *第二種 在-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event執行[self.view endEditing:YES];

     *

     */

    [self.textField resignFirstResponder];

    if (self.textField.text.length==0) {

        UIAlertView* alter=[[UIAlertView alloc]initWithTitle:@"舒適提示" message:@"你輸入的文字不能爲空" delegate:self cancelButtonTitle: @"肯定" otherButtonTitles:@"取消",nil];

        [alter show];

       }

    else{

        NSLog(@"用戶輸入了文字，文字內容是：%@",self.textField.text);

    }

}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

{

    [self.view endEditing:YES];

}

#pragma mark-UIAlertViewDelegate方法

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex

{

    if (buttonIndex==0) {

        NSLog(@"用戶開始輸入文字");

    }

}

運行結果以下：