iOS移动应用开发零碎细节随笔

1.关于视图交互的屏蔽问题

（1）下文代码段表现的视图层次关系是self.view上放置_launchScrollView，而_launchScrollView 上放置了4个launchImageView用来当欢迎界面做应用首次使用介绍，再者最后1个launchImageView中间放置comeinBtn。 

（2）现欲comeinBtnClick事件触发，且在默认情况下发现并不可行（userInteractionEnabled 默认为NO）

（3）分析：交互默认为NO,会屏蔽掉launchImageView内子视图所有点击事件和手势,所以必须要打开

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    NSInteger imageCount = 4;
    _launchScrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(0.0, 0.0, HBScreenWidth, HBScreenHeight)];
    _launchScrollView.bounces = NO;
    _launchScrollView.pagingEnabled = YES;
    _launchScrollView.showsHorizontalScrollIndicator = NO;
    _launchScrollView.contentOffset = CGPointMake(0.0, 0.0);
    _launchScrollView.contentSize = CGSizeMake(HBScreenWidth * imageCount, 0);
    
    //导入图片
    for (NSInteger i = 0; i < imageCount; i++) {
        UIImageView *launchImageView = [[UIImageView alloc]initWithFrame:CGRectMake(HBScreenWidth * i, 0.0, HBScreenWidth, HBScreenHeight)];
        UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"start_h%d", i + 1]];
        image = [image resizableImageWithCapInsets:UIEdgeInsetsMake(0.0, 0.0, 0.0, 0.0) resizingMode:UIImageResizingModeStretch];
        launchImageView.image = image;
        
        //此处交互默认为NO,会屏蔽掉launchImageView内子视图所有点击事件和手势,所以必须要打开
        launchImageView.userInteractionEnabled = YES;
        
        if (i == 3) {
            UIButton *comeinBtn = [UIButton buttonWithType:UIButtonTypeCustom];
            comeinBtn.frame = CGRectMake(HBScreenWidth * 0.42, HBScreenHeight * 0.6 , HBScreenWidth * 0.17, HBScreenHeight * 0.08);
            comeinBtn.backgroundColor = [UIColor colorWithRed:197/255.0 green:233/255.0 blue:250/255.0 alpha:1.0];
            comeinBtn.layer.borderWidth = 1.0;
            comeinBtn.titleLabel.font = [UIFont fontWithName:nil size:15.0];
            [comeinBtn setTitle:@"点击进入" forState:UIControlStateNormal];
            [comeinBtn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
            [comeinBtn addTarget:self action:@selector(comeinBtnClick) forControlEvents:UIControlEventTouchUpInside];
            [launchImageView addSubview:comeinBtn];
        }
        [_launchScrollView addSubview:launchImageView];
    }
    [self.view addSubview:_launchScrollView];
}

2.关于边框颜色和边框线条尺寸设定layer.borderColor 、borderWidth
重点在borderColor 

UITextField *searchField = [[UITextField alloc]initWithFrame:CGRectMake(0.0, 0.0, searchView.frame.size.width *2/3, searchView.frame.size.height)];
    searchField.layer.borderColor = [bedBtnColor CGColor];
    searchField.layer.borderWidth = 1.0;

3.UITableViewCell 分割线 选定Cell后背景自定义...

    //(1)cell创建后不管那种模式分割线总是不能填满tableView?[iPhone 和 iPad上可能会有所不同...(未解决)]
    //可以在UITableViewCell设置界面选择Separator Insets选择Custom,然后left,right自己定义就可,如果代码[myTableView setSeparatorInset:UIEdgeInsetsMake(0,0,0,0)];
    cell.separatorInset = UIEdgeInsetsMake(0.0, 0.0, 0.0, 0.0);
    
    //(2)分割线颜色
    _companyTableView.separatorStyle = UITableViewCellSeparatorStyleNone;
    _companyTableView.separatorColor = [UIColor clearColor];
    
 9　　　//(3)以下两句改变cell被选中后可自定义背景颜色
    cell.selectedBackgroundView = [[UIView alloc]initWithFrame:cell.frame];
 11     cell.selectedBackgroundView.backgroundColor = [UIColor grayColor];//livingBtnColor;

 

 3.字符串中关于编码的两种方式

+ (id)stringWithContentsOfFile:(NSString *)path usedEncoding:(NSStringEncoding *)enc error:(NSError **)error;

是自动判断encode，如果打开成功，把encode放在enc 里，返回给调用者。

声明一个NSStringEncoding 类型（其实就是NSUInteger）然后送指针给方法就是了。例如

1 2	NSStringEncoding enc; NSString *string = [NSString stringWithContentsOfFile:path usedEncoding:&enc error:nil];

 成功之后你可以检查 enc 以确定 string 的编码。

 

而另外一个：

+ (id)stringWithContentsOfFile:(NSString *)path encoding:(NSStringEncoding)enc error:(NSError **)error;

则是你自己知道编码，明确要求用这种编码来读取文件内容。

4.

 

实现以下三个方法，如果弹出的键盘会遮住输入框 ，整体的界面会向上移动，这样就不会遮住输入框了。自己增加UITextFieldDelegate委托。 只适合iPhone,如果想要支持iPad,只要把216改成iPad上面键盘的高度即可。 - (void)keyboardWillShow:(NSNotification *)noti {                 //键盘输入的界面调整                 //键盘的高度         float height = 216.0;                         CGRect frame = self.view.frame;                 frame.size = CGSizeMake(frame.size.width, frame.size.height - height);                 [UIView beginAnimations:@"Curl"context:nil];//动画开始                   [UIView setAnimationDuration:0.30];                    [UIView setAnimationDelegate:self];                   [self.view setFrame:frame];                  [UIView commitAnimations];          } - (BOOL)textFieldShouldReturn:(UITextField *)textField  {             // When the user presses return, take focus away from the text field so that the keyboard is dismissed.             NSTimeInterval animationDuration = 0.30f;             [UIView beginAnimations:@"ResizeForKeyboard" context:nil];             [UIView setAnimationDuration:animationDuration];             CGRect rect = CGRectMake(0.0f, 0.0f, self.view.frame.size.width, self.view.frame.size.height);             self.view.frame = rect;             [UIView commitAnimations];             [textField resignFirstResponder];     return YES;         } - (void)textFieldDidBeginEditing:(UITextField *)textField {                 CGRect frame = textField.frame;         int offset = frame.origin.y + 32 - (self.view.frame.size.height - 216.0);//键盘高度216         NSTimeInterval animationDuration = 0.30f;                         [UIView beginAnimations:@"ResizeForKeyBoard" context:nil];                         [UIView setAnimationDuration:animationDuration];         float width = self.view.frame.size.width;                         float height = self.view.frame.size.height;                 if(offset > 0)         {                 CGRect rect = CGRectMake(0.0f, -offset,width,height);                                 self.view.frame = rect;                 }                 [UIView commitAnimations];                 }

 

 5. AlertView自动隐藏,(代码模拟点击)

[AlertObject dismissWithClickedButtonIndex:0 animated:NO]

http://blog.csdn.net/likendsl/article/details/7514506