目標： 這次的學習的內容是關於在button動態方法連接多個switch 和textfield, switch判定textfield的顯示結果, 使用代碼獲取button動態方法，並且在interfaceBuilder內對button，switch和textfield進行動態交互連接，然後顯示運行結果。   編碼： // //  ViewController.h //  hhhh // //  Created by bitcar  on 12-7-10. //  Copyright (c) 2012年 bitcar . All rights reserved. //   #import <UIKit/UIKit.h> #import <Foundation/Foundation.h>   @interface ViewController : UIViewController   {     IBOutlet UITextField *passwordlength;          IBOutlet UITextField *password;          IBOutlet UISwitch *includeUpperCase;          IBOutlet UISwitch *includeLowerCase;          IBOutlet UISwitch *includeNumbers; }   @property (nonatomic, retain) UITextField *passwordlength;   @property (nonatomic, retain) UITextField *password;   @property (nonatomic, retain) UISwitch *includeUpperCase;   @property (nonatomic, retain) UISwitch *includeLowerCase;   @property (nonatomic, retain) UISwitch *includeNumbers;     //-(IBAction)setPassword:(id)sender;   - (IBAction)onPasswordButtonClick:(id)sender;   @end       #import "ViewController.h"   @implementation ViewController   @synthesize passwordlength, password;   @synthesize includeLowerCase, includeNumbers, includeUpperCase;   #define RANDOM_SEED() srandom(time(NULL))   //定義隨機值，用最小值和最大值和隨機數來計算，返回整數值 #define RANDOM_INT(_MIN_, _MAX_) ((_MIN_) +random() % ((_MAX_ +1) - (_MIN_)))   //控件輸入返回判定方法 - (BOOL) textFieldShouldReturn: (UITextField*)textField {     if(textField == password)     {         [password resignFirstResponder];//隱藏密碼文本框輸入的鍵盤     }          if(textField == passwordlength)     {         [passwordlength resignFirstResponder];//隱藏密碼長度文本框輸入的鍵盤     }   return YES; }   //button方法，點擊的密碼顯示在文本框裡 //-(IBAction)setPassword:(id)sender - (IBAction)onPasswordButtonClick:(id)sender {     //輸入密碼長度     NSInteger iPasswordLength = [passwordlength.text intValue];          //打開字母小寫     BOOL bIncludeLowerCase = includeLowerCase.on;     //打開字母大寫     BOOL bIncludeUpperCase = includeUpperCase.on;     //打開數字     BOOL bIncludeNumbers = includeNumbers.on;          NSString *passwordText = @"";     //定義a到z字母     NSString *lowercaseChars = @"abcdefghijklmnopqrstuvwxyz";     //定義A到Z字母     NSString *uppercaseChars = @"ABCDEFGHIGKLMNOPQRSTUVWXYZ";     //定義數字     NSString *numbersChars = @"1234567890";     //隨機變量     RANDOM_SEED();     //字符對象為空     NSString *passwordChars = @"";          //字母小寫的條件語句     if(bIncludeLowerCase)     {                  passwordChars =         [NSString stringWithFormat:@"%@%@", passwordChars, lowercaseChars];              }     //字母大寫的條件語句     if (bIncludeUpperCase) {         passwordChars =         [NSString stringWithFormat:@"%@%@", passwordChars, uppercaseChars];              }     //字母為數字的條件語句     if (bIncludeNumbers) {         passwordChars =         [NSString stringWithFormat:@"%@%@", passwordChars, numbersChars];              }           //數值從0開始，當數值小於密碼長度，取得數字字符，獲取的數據轉換為文字格式 for (NSInteger i=0; i<iPasswordLength; i++) {     int index = RANDOM_INT(0, [passwordChars length]-1);       NSRange range = NSMakeRange(index,1);          NSString *passwordChar = [passwordChars substringWithRange:range];          passwordText =     [NSString stringWithFormat:@"%@%@", passwordText, passwordChar];      }   password.text = @"";   password.text = passwordText;   }   - (void)viewDidLoad {     [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. }   - (void)didReceiveMemoryWarning {     [super didReceiveMemoryWarning];     // Dispose of any resources that can be recreated. }   - (void) dealloc {     [passwordlength release];     [password release];     [includeNumbers release];     [includeLowerCase release];     [includeUpperCase release];     [super dealloc]; }   @end       運行程序：