- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor yellowColor];
    [self.window makeKeyAndVisible];
    
    UILabel *red = [[UILabel alloc] initWithFrame:CGRectMake(30, 100, 90, 30)];
    red.backgroundColor = [UIColor redColor];
    red.text = @"Red";
    red.textColor = [UIColor whiteColor];
    red.textAlignment = NSTextAlignmentCenter;
    red.font = [UIFont systemFontOfSize:25];
    [self.window addSubview:red];
    [red release];
    
    UITextField *redNumber = [[[UITextField alloc] initWithFrame:CGRectMake(140, 95, 200, 40)] autorelease];
    redNumber.borderStyle = UITextBorderStyleRoundedRect;
    redNumber.placeholder = @"输入0~255之间的数字";
    redNumber.keyboardType = UIKeyboardTypeNumberPad;
    redNumber.tag = 101;
    [self.window addSubview:redNumber];
    
    
    UILabel *green = [[UILabel alloc] initWithFrame:CGRectMake(30, 160, 90, 30)];
    green.backgroundColor = [UIColor greenColor];
    green.text = @"Green";
    green.textColor = [UIColor whiteColor];
    green.textAlignment = NSTextAlignmentCenter;
    green.font = [UIFont systemFontOfSize:25];
    [self.window addSubview:green];
    [green release];
    
    UITextField *greenNumber = [[[UITextField alloc] initWithFrame:CGRectMake(140, 155, 200, 40)] autorelease];
    greenNumber.borderStyle = UITextBorderStyleRoundedRect;
    greenNumber.placeholder = @"输入0~255之间的数字";
    greenNumber.keyboardType = UIKeyboardTypeNumberPad;
    greenNumber.tag = 102;
    [self.window addSubview:greenNumber];
    
    
    UILabel *blue = [[UILabel alloc] initWithFrame:CGRectMake(30, 220, 90, 30)];
    blue.text = @"Blue";
    blue.backgroundColor = [UIColor blueColor];
    blue.textAlignment = NSTextAlignmentCenter;
    blue.textColor = [UIColor whiteColor];
    blue.font = [UIFont systemFontOfSize:25];
    [self.window addSubview:blue];
    [blue release];
    
    
    UITextField *blueNumber = [[[UITextField alloc] initWithFrame:CGRectMake(140, 215, 200, 40)] autorelease];
    blueNumber.borderStyle = UITextBorderStyleRoundedRect;
    blueNumber.placeholder = @"输入0~255之间的数字";
    blueNumber.keyboardType = UIKeyboardTypeNumberPad;
    blueNumber.tag = 103;
    [self.window addSubview:blueNumber];
    
    
    UIButton *submit = [UIButton buttonWithType:UIButtonTypeSystem];
    submit.backgroundColor = [UIColor colorWithRed:0.257 green:1.000 blue:0.972 alpha:1.000];
    submit.frame = CGRectMake(160, 300, 60, 40);
    [submit setTitle:@"提交" forState:UIControlStateNormal];
    [self.window addSubview:submit];
    
    [submit addTarget:self action:@selector(submit) forControlEvents:UIControlEventTouchUpInside];
    
    return YES;
}


- (void)submit {
    UITextField *temp101 = (UITextField *)[self.window viewWithTag:101];
    UITextField *temp102 = (UITextField *)[self.window viewWithTag:102];
    UITextField *temp103 = (UITextField *)[self.window viewWithTag:103];
    self.window.backgroundColor = [UIColor colorWithRed:[temp101.text intValue] / 255.0 green:[temp102.text intValue]/ 255.0 blue:[temp103.text intValue] / 255.0 alpha:1];
}