1:用UIImageView作为背景，但直接把按钮或者UITextField放在上面无法相应事件。
解决办法：UIImageView默认的UserInteractionEnabled是NO，把它修改成YES,或者可以直接在XCODE上面的view有个属性勾选User Interaction Enabled
遇到的场景(在滚动视图里面放一个图片视图，在图片视图上又放置一个按键，发现一直没有响应效果);
2:AFnetWorking报"Request failed: unacceptable content-type: text/html"
对应到自己的项目里面，我用的是AFNetworking这套网络请求包，需要改的是：
AFURLResponseSerialization.m文件
223行：
self.acceptableContentTypes= [NSSetsetWithObjects:@"application/json",@"text/html",@"text/json",@"text/javascript", nil];
加上@"text/html",部分，其实就是添加一种服务器返回的数据格式。
3:NSMutableArray和NSArray的相互转换
//NSArray --> NSMutableArrayNSMutableArray *myMutableArray =[myArray mutableCopy];//NSMutableArray --> NSArrayNSArray *myArray = [myMutableArray copy];
4:自定义系统导航条上面的返回按钮，以及文字，右侧收藏按钮
//中间标题UILabel *navLabel = [[UILabel alloc] initWithFrame:CGRectMake(0,0,320,44)];
navLabel.text=@"团购详情";
navLabel.textColor=[UIColor whiteColor];
navLabel.font= [UIFont systemFontOfSize:18];
navLabel.textAlignment=NSTextAlignmentCenter;
self.navigationItem.titleView=navLabel;//右边收藏按钮UIButton *rightButton =[UIButton buttonWithType:UIButtonTypeCustom];
rightButton.frame= CGRectMake(0,0,20,20);
[rightButton setBackgroundImage:LOAD_IMAGE(@"meishoucang") forState:UIControlStateNormal];
[rightButton addTarget:self action:@selector(doShouCang) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem*rightItem =[[UIBarButtonItem alloc] initWithCustomView:rightButton];
self.navigationItem.rightBarButtonItem=rightItem;//左边返回按钮UIButton *fanHuiButton =[UIButton buttonWithType:UIButtonTypeCustom];
fanHuiButton.frame= CGRectMake(0,0,30,40);
[fanHuiButton setBackgroundImage:LOAD_IMAGE(@"fanhuijiantou") forState:UIControlStateNormal];
[fanHuiButton addTarget:self action:@selector(doFanHui) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem*leftItem =[[UIBarButtonItem alloc] initWithCustomView:fanHuiButton];
self.navigationItem.leftBarButtonItem=leftItem;
导航条上的title字体， 字号 可以这么定义，完全使用系统的
[self.navigationController.navigationBar setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:
[UIColor colorWithRed:1.0/255green:1.0/255blue:1.0/255alpha:1], UITextAttributeTextColor,[UIColor clearColor],UITextAttributeTextShadowColor,[UIFont systemFontOfSize:20],UITextAttributeFont,nil]];
5:清理UITableView底部空的列
self.tableView.tableFooterView = [[UIView alloc] init];
6:如何隐藏navigation跳转后的头部右键
//隐藏头部左边的返回self.navigationItem.hidesBackButton=YES;//隐藏头部右边self.navigationItem.rightBarButtonItem.customView.hidden=YES;
7:如要给UICollectionViewController视图设置背景图
UIImage *image=[UIImage imageNamed:@"AppBg"];
self.collectionView.layer.contents=(id)image.CGImage;
8:可以在其它地方修改rootViewController
UIWindow *window =[UIApplication sharedApplication].keyWindow;
window.rootViewController= [[HVWTabBarViewController alloc] init];
9:新浪微博授权登录报Warning: Attempt toPResent on whose view is not in the window hierarchy!
IntroductoryViewController *introductory=[mainStoryboard instantiateViewControllerWithIdentifier:@"introductoryview"];
UINavigationController*rootNavigationController=[[UINavigationController alloc] initWithRootViewController:introductory];
self.window.rootViewController=rootNavigationController;
主要问题是a跳转到b,然后b放一个授权新浪微博的按键，增加一个UINavigationController，然后在a跳转到b时用nav跳转：
UIStoryboard*mainStoryboard=[UIStoryboard storyboardWithName:@"Main"bundle:nil];
LoginViewController* loginviewControll=[mainStoryboard instantiateViewControllerWithIdentifier:@"loginviewcontroller"];
[self.navigationController pushViewController:loginviewControll animated:YES];
10:在引入第三方TcweiboSDK报linker command failed with exit code1(use -v to see invocation)
是因为重复引入libTCWeiboSDK这个类库，TARGETS-PROJECT-Build Phases-Link Binary With Libraries中，有三个libTcweiboSDK,可以删除libTCWeiboSDK-I386.a
11:NSUserDefaults存放民NSDictionary
注意：NSUserDefaults支持的数据类型有NSString、 NSNumber、NSDate、 NSArray、NSDictionary、BOOL、NSInteger、NSFloat等系统定义的数据类型。
本次遇到的问题：当NSDictionary里面的值为null时，要写入NSUserDefaults会报异常（attempt to insert non-property listobject）；
解决方式：把字典中的值进行过滤处理，为空的转化成字符串的空值；代码如下(创建一个扩展类):
@implementation NSDictionary(Common)-(NSDictionary *) changeDictionaryNotNill
{
NSMutableDictionary*muResult=[[NSMutableDictionary alloc]init];
NSEnumerator*enumerator=[self keyEnumerator];
id key;while((key=[enumerator nextObject])) {
id value=[self objectForKey:key];if((NSNull *)value==[NSNullnull]) {
[muResult setObject:@""forKey:key];
}else{
[muResult setObject:value forKey:key];
}
}returnmuResult;
}
@end