TonnyXu

Overview

NSURLConnection is really a complex and convenient class for handling low level connections. Usually, you use NSURLConnection class to establish an FTP/HTTP/HTTPS/FILE connections and get data from remote servers or local files. NSURLConnection aimed to be flexible and handy for some common tasks like redirect/authentication/cache. Also, before iOS 4.0, it adopted delegate design pattern, will send the request to remote server in separated thread automatically.

Let's talk about cache

1. NSURLConnection provide both on-disk and in-memory cache.
2. There are two types of cache: local cache and remote cache.
3. Setting cache policy when create a NSURLRequest instance is ONLY for local cache.
4. Currently only responses to HTTP and HTTPS are cached.

TonnyXu

NSCache, NSURLCache, NSCachedResponse in Fundation.framework

NSCache

• Is an in memory cache mechanism
• Just like NSMutableDictionary
• Available when iOS > 4.0
• Can be set with a limit

See Document for more information.

TonnyXu

//...

  [self.tabBarController.tabBar.items enumerateObjectsUsingBlock:^(UITabBarItem *aTabBarItem, NSUInteger idx, BOOL *stop) {
    NSString *selectedImageName = [NSString stringWithFormat:@"tab_icon%d_27x27_selected", idx+1];
    NSString *unselectedImageName = [NSString stringWithFormat:@"tab_icon%d_27x27", idx+1];
    [aTabBarItem setFinishedSelectedImage:[UIImage imageNamed:selectedImageName] 
              withFinishedUnselectedImage:[UIImage imageNamed:unselectedImageName]];
    
    [aTabBarItem setTitleTextAttributes:[NSDictionary dictionaryWithObjectsAndKeys:
                                         [[UIColor blackColor] colorWithAlphaComponent:0.5], UITextAttributeTextShadowColor, 

TonnyXu

Question

How to implement a UITableView with a separator line like this:

Usually, you can only set the separatorLine property of a UITableView with to single line or single line etched. Sometimes, it is not enough. So, how to implement a separator line like this?

Answer

TonnyXu

diff -r mixiIOSSDK-1.3.2/History.txt mixiIOSSDK-1.3.3/History.txt
0a1,3
> v1.3.3 2012-03-15
> - 不具合修正（UserDefaults）
> 
diff -r mixiIOSSDK-1.3.2/README.markdown mixiIOSSDK-1.3.3/README.markdown
62c62
<   <tr><td><a href="http://developer.mt.mixi.co.jp/connect/appli/spec/ios/download/mixiIOSSDK-1.3.2.zip">mixiIOSSDK-1.3.2.zip</a></td><td>v1.3.2</td><td>600KB</td><td>2012-03-01</td></tr>
---
>   <tr><td><a href="http://developer.mt.mixi.co.jp/connect/appli/spec/ios/download/mixiIOSSDK-1.3.3.zip">mixiIOSSDK-1.3.3.zip</a></td><td>v1.3.3</td><td>600KB</td><td>2012-03-15</td></tr>

TonnyXu

UIImage has a property named imageOrientation

See Apple's documentation: imageOrientation

What's the header looks like?

typedef enum {
 UIImageOrientationUp, // default orientation

TonnyXu

A wired compiler error

Have you ever seen a compiler error like:

error: expected a property attribute before 'strong'

I met one today. The same code was compiled and worked fine in my iPhone project but another similar iPad version could not pass the compilation. WTF? After googling it. I found the reason.

Solution

TonnyXu

//
//  QuickSort.c
//  algorithms-iOS
//
//  Created by Tonny Xu on 2/6/12.
//  Copyright (c) 2012 Tonny Xu. All rights reserved.
//

#include <stdio.h>
#include <stdlib.h>

TonnyXu

//
//  CLRS_BubbleSort.c
//  algorithms-iOS
//
//  Created by Tonny Xu on 2/2/12.
//  Copyright (c) 2012 Tonny Xu. All rights reserved.
//

#include <stdio.h>
#include <sys/time.h>

TonnyXu

The point is, the roundCorner is draw by a subview of UITableViewCell, and mean while, it's not a public class, there is no way you can get layer.cornerRadius from any view. So we need to resolve this problem by ourselves.

There are 2 cases.

1. There is only one cell.

   This case is ease, just use cell.contentView.layer.cornerRadius and cell.contentView.layer.masksToBounds to make it work.

2. There are more than one cell.