[iOS Dev] UILocalNotification in particular time - 指定時間本地通知

Add Local Notification at particular time

Cancel one particular LocalNotification

[iOS Dev] Parsing JSON data from file.

Source code:

[iOS Dev] 偵測目前網路狀態 WIFI, 3G, Edge - Reachability

一年前寫過一個範例 : [iOS Dev] 簡單的網路連結測試 Simple Internet Connection test

主要是透過NSURL去實際request一個網頁, 然後偵測是否可以連結

今天發現使用Apple有提供一個Sample Code - Reachability, 直接透過C語言的Library來偵測網路狀態

並可以偵測使用者是否使用WIFI, 3G, Edge網路 直接import Reachability.h就可以沿用, 非常方便 

注意: 使用Reachability時, 要記得在專案link SystemConfiguration.framework

詳細請看官方範例::
http://developer.apple.com/library/ios/#samplecode/Reachability/Introduction/Intro.html

[iOS Dev] 實作Open in Safari

[iOS Dev] 開啓殭屍模式 找出EXC_BAD_ACCESS元兇

通常會出現EXC_BAD_ACCESS通常是哪個Object已經被release或是根本不存在

可以開啟Zombie Object來觀看到底是哪個Object不存在

1. ⌥ + ⌘ + R

2. 打勾Enable Zombie Objects

Reference:
http://stackoverflow.com/questions/2190227/how-do-i-setup-nszombieenabled-in-xcode-4

[iOS Dev] 不要套用UIBarStyleBlackTranslucent在NavigationBar上

今天用UIBarStyleBlackTranslucent在NavigationBar上, 發現整個top的位置會跑掉, 然後搜尋過後原來也有人遇到一樣的問題 Reference: http://stackoverflow.com/questions/228319/navigation-controller-transparent-bar-style-is-not-working

[iOS Dev] 點擊狀態列捲軸往上問題 Tap statusbar scroll to top doesn't work

我有一個UITableView結果發現scroll到下面時

竟然無法點statusbar自動捲到最上面

後來發現是因為我的UITableViewCell裡有UIWebView, 所以action被搶走了

所以只要把UIWebView的scroll to top關掉, 就可以避免這個問題

Code (iOS5):

webView.scrollView.scrollsToTop = NO; 

[iOS Dev] 更改UIKeyboard的底色為黑色

    [inputTextView becomeFirstResponder];
    [inputTextView setKeyboardAppearance:UIKeyboardAppearanceAlert];

原本的Default

更改keyboardAppearance 為 UIKeyboardAppearanceAlert

[iOS Dev] NSArray字串合併成NSString - How to join NSArray elements into an NSString?

Code:
Result:

Apple iOS 5.1

Reference: http://stackoverflow.com/questions/1387440/how-to-join-nsarray-elements-into-an-nsstring

[iOS Dev] 關掉UIWebView的垂直拖曳反彈 Disable UIWebView "bouncing" vertically

Reference http://stackoverflow.com/questions/500761/stop-uiwebview-from-bouncing-vertically

[iOS Dev] Parse query string into dictionary

Usage:

NSString *qs = @"username=hank&age=27&blog=whhnote.blogspot.com";
NSDictionary *queryParams = [self parseQueryString:qs];
NSLog(@"%@", queryParams);
NSLog(@"%@", [queryParams objectForKey:@"username"]); // get username from dict

So, you will get a dictionary look like

{
    age = 27;
    blog = "whhnote.blogspot.com";
    username = hank;
}

[iOS Dev] NSUserDefaults Save/Read/Clear 儲存/讀取/清除 速記

參考: NSUserDefaults Class Reference

[iOS Dev] Detect App Running on Simulator or Actual Device - 判斷App執行在模擬器或是實體

對於開發時要設定不同參數很有幫助
It's helpful to set different config.

#if TARGET_IPHONE_SIMULATOR
  // It's running on the simulator 目前跑在模擬器上
#else
  // Running on Actual Device  在實機上跑
#endif

[iOS Dev] 日期轉換 Date and Timestamp converter

NSDate *now = [NSDate date];
NSTimeInterval interval = [now timeIntervalSince1970];
NSLog(@"%@", now);   // Date
NSLog(@"%f", interval);    // Date to Timesatmp
NSLog(@"%@", [NSDate dateWithTimeIntervalSince1970:interval]); // Timestamp to Date

[iOS Dev] UITextView圓角邊緣 Corner Radius

#import <QuartzCore/QuartzCore.h>
txtView.layer.cornerRadius = 5;

See Also

how to set rounded corner for a UITextView ?

[iOS Dev] Filter FetchedResultsController with NSPredicate

NSPredicate *predicate = [NSPredicate predicateWithFormat:
[NSString stringWithFormat:@"(firstName like '%@')", @"Hank"]];

NSArray *items = [fetchedResultsController.fetchedObjects filteredArrayUsingPredicate:predicate];
 
 for (NSManagedObject *o in items) {
  NSLog(@"%@", o);
 }

[iOS Dev] NSDate, NSString conversion and get TimeZone

[iOS Dev] Load Image From URL

[iOS Dev] 取得目前View的大小跟位置

CGRect f = self.view.frame;
NSLog(@"w=%f, h=%f", f.size.width, f.size.height);
NSLog(@"x=%f, y=%f", f.origin.x, f.origin.y);

[iOS Dev] UITableView indentationLevel 縮排

- (NSInteger)tableView:(UITableView *)tableView indentationLevelForRowAtIndexPath:(NSIndexPath *)indexPath {
 NSUInteger row = [indexPath row];
 return row;
}