iPhone/iPod Touch: Icon.png: icon dimensions (72 x 72) don't meet the size requirements. The icon file must be 57x57 pixels, in .png format

iPhone/iPod Touch: Icon.png: icon dimensions (72 x 72) don't meet the size requirements. The icon file must be 57x57 pixels, in .png format

Edit Project Settings -> Build -> uncheck Compress PNG Files，就可以了

取得keyboard 座標和寬高（CGRect）

- (void) keyboardWillShow:(NSNotification*) notification

{

    NSDictionary* info = [notification userInfo];

    NSValue* aValue = [info objectForKey:UIKeyboardFrameEndUserInfoKey];

    CGRect keyboardRect = [aValue CGRectValue];

    NSLog(@"keyboardRect y:%f height:%f", keyboardRect.origin.y, keyboardRect.size.height);

}

iOS MD5編碼

#import <CommonCrypto/CommonDigest.h>

@implementation NSString(MD5)

- (NSString*)MD5

{

// Create pointer to the string as UTF8

  const char *ptr = [self UTF8String];

  // Create byte array of unsigned chars

  unsigned char md5Buffer[CC_MD5_DIGEST_LENGTH];

// Create 16 bytes MD5 hash value, store in buffer

  CC_MD5(ptr, strlen(ptr), md5Buffer);

// Convert unsigned char buffer to NSString of hex values

  NSMutableString *output = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];

  for(int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) 

[output appendFormat:@"%02x",md5Buffer[i]];

  return output;

}

@end

iOS 建立UUID

#import "CreateUUID.h"

@implementation CreateUUID

+ (NSString *)createUUID

{

    // Create universally unique identifier (object)

    CFUUIDRef uuidObject = CFUUIDCreate(kCFAllocatorDefault);

    

    // Get the string representation of CFUUID object.

    NSString *uuidStr = [(NSString *)CFUUIDCreateString(kCFAllocatorDefault, uuidObject) autorelease];

    

    // If needed, here is how to get a representation in bytes, returned as a structure

    // typedef struct {

    //   UInt8 byte0;

    //   UInt8 byte1;

    //   ...

    //   UInt8 byte15;

    // } CFUUIDBytes;

    CFUUIDBytes bytes = CFUUIDGetUUIDBytes(uuidObject);

    

    CFRelease(uuidObject);

    

    return uuidStr;

}

@end

iOS ThreeDESBase64

#import "ThreeDESBase64.h"

#import <CommonCrypto/CommonCryptor.h>

#import "GTMBase64.h"

@implementation ThreeDESBase64

+ (NSString*)TripleDES:(NSString*)plainText encryptOrDecrypt:(CCOperation)encryptOrDecrypt key:(NSString*)key 

{    

    const void *vplainText;

    size_t plainTextBufferSize;

    

    if (encryptOrDecrypt == kCCDecrypt)

    {

        NSData *EncryptData = [GTMBase64 decodeData:[plainText dataUsingEncoding:NSUTF8StringEncoding]];

        plainTextBufferSize = [EncryptData length];

        vplainText = [EncryptData bytes];

    }

    else

    {

        NSData* data = [plainText dataUsingEncoding:NSUTF8StringEncoding];

        plainTextBufferSize = [data length];

        vplainText = (const void *)[data bytes];

    }

    

    CCCryptorStatus ccStatus;

    uint8_t *bufferPtr = NULL;

    size_t bufferPtrSize = 0;

    size_t movedBytes = 0;

    // uint8_t ivkCCBlockSize3DES;

    

    bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);

    bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));

    memset((void *)bufferPtr, 0x0, bufferPtrSize);

    // memset((void *) iv, 0x0, (size_t) sizeof(iv));

    

    //    NSString *key = @"123456789012345678901234";

    NSString *initVec = @"init Vec";

    const void *vkey = (const void *) [key UTF8String];

    const void *vinitVec = (const void *) [initVec UTF8String];

    

    ccStatus = CCCrypt(encryptOrDecrypt,

                       kCCAlgorithm3DES,

                       kCCOptionPKCS7Padding,

                       vkey, //"123456789012345678901234", //key

                       kCCKeySize3DES,

                       vinitVec, //"init Vec", //iv,

                       vplainText, //"Your Name", //plainText,

                       plainTextBufferSize,

                       (void *)bufferPtr,

                       bufferPtrSize,

                       &movedBytes);

    //if (ccStatus == kCCSuccess) NSLog(@"SUCCESS");

    /*else if (ccStatus == kCC ParamError) return @"PARAM ERROR";

     else if (ccStatus == kCCBufferTooSmall) return @"BUFFER TOO SMALL";

     else if (ccStatus == kCCMemoryFailure) return @"MEMORY FAILURE";

     else if (ccStatus == kCCAlignmentError) return @"ALIGNMENT";

     else if (ccStatus == kCCDecodeError) return @"DECODE ERROR";

     else if (ccStatus == kCCUnimplemented) return @"UNIMPLEMENTED"; */

    

    NSString *result;

    

    if (encryptOrDecrypt == kCCDecrypt)

    {

        result = [[[NSString alloc] initWithData:[NSData dataWithBytes:(const void *)bufferPtr 

                                                                length:(NSUInteger)movedBytes] 

                                        encoding:NSUTF8StringEncoding] 

                  autorelease];

    }

    else

    {

        NSData *myData = [NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)movedBytes];

        result = [GTMBase64 stringByEncodingData:myData];

    }

    

    return result;    

} 

如何在 XCode 4.2 設定部分程式碼不使用 ARC 方式分享

1. 選擇專案，此時會出現專案設定畫面。 2. 選擇你的 Target，並切換到 Build Phases 畫面。 3. 找到 Compile Sources 這個畫面，然後選擇你要設定不使用 ARC 的程式碼 4. 按下 Enter 鍵後，會跳出一個視窗要你輸入東西，在裏面輸入 -fno-objc-arc 就可以了。

UITableView 新增下拉更新（Pull-refresh）

https://github.com/enormego/EGOTableViewPullRefresh

一、找到你的UITableView / UITableViewController 的.h 文件，結合以下代碼，添加相應的元素：

#import "EGORefreshTableHeaderView.h"

@interface RootViewController : UITableViewController  {

EGORefreshTableHeaderView *_refreshHeaderView;

//  Reloading var should really be your tableviews datasource
//  Putting it here for demo purposes
BOOL _reloading;
}

- (void)reloadTableViewDataSource;
- (void)doneLoadingTableViewData;
@end


二、切換到你的UITableView / UITableViewController 的.m 文件，結合以下代碼，添加相應的元素：

- (void)viewDidLoad {
[super viewDidLoad];

if (_refreshHeaderView == nil) {

EGORefreshTableHeaderView *view = [[EGORefreshTableHeaderView alloc] initWithFrame:CGRectMake(0.0f, 0.0f - self.tableView.bounds.size.height, self.view.frame.size.width, self.tableView.bounds.size.height)];
view.delegate = self;
[self.tableView addSubview:view];
_refreshHeaderView = view;
[view release];

}

//  update the last update date
[_refreshHeaderView refreshLastUpdatedDate];
}

#pragma mark -
#pragma mark Data Source Loading / Reloading Methods

- (void)reloadTableViewDataSource{

//  should be calling your tableviews data source model to reload
//  put here just for demo
_reloading = YES;

}

- (void)doneLoadingTableViewData{

//  model should call this when its done loading
_reloading = NO;
[_refreshHeaderView egoRefreshScrollViewDataSourceDidFinishedLoading:self.tableView];

}

#pragma mark -
#pragma mark UIScrollViewDelegate Methods

- (void)scrollViewDidScroll:(UIScrollView *)scrollView{

[_refreshHeaderView egoRefreshScrollViewDidScroll:scrollView];



}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{

[_refreshHeaderView egoRefreshScrollViewDidEndDragging:scrollView];

}

#pragma mark -
#pragma mark EGORefreshTableHeaderDelegate Methods

- (void)egoRefreshTableHeaderDidTriggerRefresh:(EGORefreshTableHeaderView*)view{

[self reloadTableViewDataSource];
[self performSelector:@selector(doneLoadingTableViewData) withObject:nil afterDelay:3.0];

}

- (BOOL)egoRefreshTableHeaderDataSourceIsLoading:(EGORefreshTableHeaderView*)view{

return _reloading; // should return if data source model is reloading

}

- (NSDate*)egoRefreshTableHeaderDataSourceLastUpdated:(EGORefreshTableHeaderView*)view{

return [NSDate date]; // should return date data source was last changed

}


三、最後呢，為了彰顯你良好的內存管理習慣，別忘了釋放掉相應的UI 元素：

- (void)viewDidUnload {
_refreshHeaderView=nil;
}

- (void)dealloc {

_refreshHeaderView = nil;
[super dealloc];
}

四、編譯之前，別忘了將EGORefreshTableHeaderView.h、EGORefreshTableHeaderView.m兩個文件，以及Enormego提供的那一套圖片包拖進你的工程裡。

五、很抱歉沒有第五步了，編譯你的工程，打開simulator ，看看效果吧。包你滿意。
其實還沒完，這裡補充一點花絮。關於這個Pull & Refresh 功能的完整版來龍去脈。其實呢，最早出現這個Pull & Refresh 功能的app 是Tweetie 2 ，也就是現在大家每天都在用的Twitter for iPhone 的前身。因為這個小功能實在是很好用很貼心，所以就被Enormego 團隊發現了。但是Tweetie 2 是閉源的，於是很牛逼很強大的Enormego 就自己寫了一個，並且很大方的放到GitHub 上開源了。但是諸位如果仔細回憶一下，不難發現，真正讓這個Pull & Refresh 走紅的，是Facebook 旗下的Three20 開源框架。