iPhone开发中的技巧整理（二）

-(NSString *) getWeek:(NSDate *)d

{

NSCalendar *calendar = [[NSCalendar alloc]

initWithCalendarIdentifier:NSGregorianCalendar];

unsigned units = NSYearCalendarUnit | NSMonthCalendarUnit |

NSDayCalendarUnit | NSWeekCalendarUnit;

NSDateComponents *components = [calendar components:units

fromDate:d];

[calendar release];

switch ([components weekday]) {

case1:

return @"Monday"; break;

case2:

return @"Tuesday"; break;

case3:

return @"Wednesday"; break;

case4:

return @"Thursday"; break;

case5:

return @"Friday"; break;

case6:

return @"Saturday"; break;

case7:

return @"Sunday"; break;

default:

return @"NO Week"; break;

}

NSLog(@"%@",components); 

}

 

2、将网络数据读取为字符串

-(NSString *)getDataByURL:(NSString *)url {

return [[NSString alloc] initWithData:[NSData dataWithContentsOfURL: [NSURL URLWithString:[url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]] encoding:NSUTF8StringEncoding];

}

 

3、读取⺴络图⽚

-(UIImage *)getImageByURL:(NSString *)url {

return [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL: [NSURL URLWithString:[url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]]];

}

 

4、多线程(这种方式,只管建立线程,不管回收线程)

[NSThread detachNewThreadSelector:@selector(scheduleTask) toTarget:self withObject:nil];

-(void)scheduleTask

{

NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

[pool release]; 

}

 

如果有参数,则这么⽤

[NSThread detachNewThreadSelector:@selector(scheduleTask:) toTarget:self withObject:[NSDate date]];

-(void)scheduleTask:(NSDate *)mdate

{

NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

[pool release]; }

 

在线程⾥运⾏主线程⾥的⽅法

[self performSelectorOnMainThread:@selector(moveToMain) withObject:nil waitUntilDone:FALSE];

 

5、⽤户缺省值NSUserDefaults读取:

NSUserDefaults *df = [NSUserDefaults standardUserDefaults];

NSArray *languages = [df objectForKey:@"AppleLanguages"]; 

NSLog(@"all language is %@",languages);

NSLog(@"index is %@",[languages objectAtIndex:0]);

NSLocale *currentLocale = [NSLocale currentLocale];

NSLog(@"language Code is %@",[currentLocale objectForKey:NSLocaleLanguageCode]); 

NSLog(@"Country Code is %@",[currentLocale objectForKey:NSLocaleCountryCode]);

 

6、view之间转换的动态效果设置

SecondViewController *secondViewController = [[SecondViewController alloc] init];

secondViewController.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;//⽔水平翻转

[self.navigationController presentModalViewController:secondViewController animated:YES];

[secondViewController release];

 

 

7、UIScrollView 滑动用法: -(void)scrollViewDidScroll:(UIScrollView *)scrollView

{

NSLog(@"正在滑动中。。")

}

//⽤户直接滑动UIScrollView,可以看到滑动条

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

}

//通过其他控件触发UIScrollView滑动,看不到滑动条

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

}

//UIScrollView 设置滑动不超出本⾝身范围

[scrollView setBounces:NO]; 

 

8、iphone的系统目录:

//得到Document:目录

NSArray *paths =

NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *documentsDirectory = [paths objectAtIndex:0];

//得到temp临时目录

NSString *temPath = NSTemporaryDirectory();

//得到目录上的文件地址

NSString *address = [paths stringByAppendingPathComponent:@"1.rtf"];

 

9、状态栏显⽰示indicator

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

 

10、app Icon显示数字:

- (void)applicationDidEnterBackground:(UIApplication *)application

{

 

 [[UIApplication sharedApplication] setApplicationIconBadgeNumber:5];

}

11、sqlite保存地址:

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectoryNSUserDomainMask, YES);

NSString *thePath = [paths objectAtIndex:0];

NSString *filePath = [thePath stringByAppendingPathComponent:@"kilometer.sqlite"];

NSString *dbPath = [[[NSBundle mainBundle] resourcePathstringByAppendingPathComponent:@"kilometer2.sqlite"];

 

12、键盘弹出隐藏,textfield变位置

_tspasswordTF = [[UITextField alloc] initWithFrame: CGRectMake(100,

150, 260, 30)];

_tspasswordTF.backgroundColor = [UIColor redColor];

_tspasswordTF.tag = 2;

/*

Use this method to release shared resources, save user data,

_tspasswordTF.delegate = self;

[self.window addSubview: _tspasswordTF];

 

- (void)textFieldDidBeginEditing:(UITextField *)textField {

[self animateTextField: textField up: YES]; 

}

 

- (BOOL)textFieldShouldReturn:(UITextField *)textField {

[self animateTextField: textField up: NO]; 

[textField resignFirstResponder];

return YES;

}

- (void) animateTextField: (UITextField*) textField up: (BOOL) up {

const int movementDistance = 80; 

// tweak as needed 

const float movementDuration = 0.3f; 

// tweak as needed

int movement = (up ? -movementDistance : movementDistance);

[UIView beginAnimations: nil context: nil]; [UIView setAnimationBeginsFromCurrentState: YES]; [UIView setAnimationDuration: movementDuration];

self.window.frame = CGRectOffset(self.window.frame, 0, movement);

[UIView commitAnimations]; 

}

 

13、获取图片的尺⼨

CGImageRef img = [imageView.image CGImage]; 

NSLog(@"%d",CGImageGetWidth(img)); 

NSLog(@"%d",CGImageGetHeight(img));

 

14、AlertView,ActionSheet的cancelButton点击事件:

- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex: (NSInteger)buttonIndex; // before animation and hiding view

{

  NSLog(@"cancel alertView... buttonindex = %d",buttonIndex); //当⽤用户按下Cancel按钮

  if (buttonIndex == [alertView cancelButtonIndex]){

  exit(0); 

  }

}

- (void)actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex

{

NSLog(@"%s %d button = %d cancel actionSheet.....",__FUNCTION__,__LINE__, buttonIndex);

//当⽤用户按下Cancel按钮

  if (buttonIndex == [actionSheet cancelButtonInd

补充：移动开发 , IOS ,