iphone开发笔记
- (BOOL) textFieldShouldReturn:(id)textField{
[textField resignFirstResponder];
}
CGRect frame = CGRectMake (origin.x, origin.y, size.width, size.height)；矩形
NSStringFromCGRect(someCG)把CGRect结构转变为格式化字符串；
CGRectFromString(aString)由字符串恢复出矩形；
CGRectInset(aRect)创建较小或较大的矩形（中心点相同），＋较小－较大
CGRectIntersectsRect(rect1, rect2)判断两矩形是否交叉，是否重叠
CGRectZero高度和宽度为零的／位于（0，0）的矩形常量
CGPoint aPoint = CGPointMake(x, y);
CGSize aSize = CGSizeMake(width, height);
[myView setAlpha:value]; (0.0 < value < 1.0)
[myView setBackgroundColor:[UIColor redColor]];
(blackColor;darkGrayColor;lightGrayColor;
whiteColor;grayColor; redColor; greenColor;
blueColor; cyanColor;yellowColor;
magentaColor;orangeColor;purpleColor;
brownColor; clearColor; )
UIColor *newColor = [[UIColor alloc]
initWithRed:(float) green:(float) blue:(float) alpha:(float)];
0.0~1.0
320X480
480X320
20像素
44像素
[[UIApplication shareApplication] setStatusBarHidden: YES animated:NO]
[[UIApplication shareApplication]
setStatusBarOrientation:UIInterfaceOrientationLandscapeRight].
orientation == UIInterfaceOrientationLandscapeLeft
window=[[UIWindow alloc] initWithFrame:[UIScreen mainScreen] bounds];
aView.autoresizingSubviews = YES;
aView.autoresizingMask = (UIViewAutoresizingFlexibleWidth |
UIViewAutoresizingFlexibleHeight);
UIButton *scaleUpButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[scaleUpButton setTitle:@"放 大" forState:UIControlStateNormal];
scaleUpButton.frame = CGRectMake(40, 420, 100, 40);
[scaleUpButton addTarget:self
action:@selector(scaleUp)
forControlEvents:UIControlEventTouchUpInside];
UIImageView *aView;
[aView setImage:[UIImage imageNamed:@”name.png”]];
view1.backgroundColor = [UIColor colorWithPatternImage:
[UIImage imageNamed:@"image1.png"]];
自定义UISlider的样式和滑块
我们使用的是UISlider的setMinimumTrackImage，和setMaximumTrackImage方法来定义图片的，这两个方法可以设置滑块左边和右边的图片的，不过如果用的是同一张图片且宽度和控件宽度基本一致，就不会有变形拉伸的后果，先看代码，写在viewDidLoad中：
//左右轨的图片
UIImage *stetchLeftTrack= [UIImage imageNamed:@"brightness_bar.png"];
UIImage *stetchRightTrack = [UIImage imageNamed:@"brightness_bar.png"];
//滑块图片
UIImage *thumbImage = [UIImage imageNamed:@"mark.png"];
UISlider *sliderA=[[UISlider alloc]initWithFrame:CGRectMake(30, 320, 257, 7)];
sliderA.backgroundColor = [UIColor clearColor];
sliderA.value=1.0;
sliderA.minimumValue=0.7;
sliderA.maximumValue=1.0;
[sliderA setMinimumTrackImage:stetchLeftTrack forState:UIControlStateNormal];
[sliderA setMaximumTrackImage:stetchRightTrack forState:UIControlStateNormal];
//注意这里要加UIControlStateHightlighted的状态，否则当拖动滑块时滑块将变成原生的控件
[sliderA setThumbImage:thumbImage forState:UIControlStateHighlighted];
[sliderA setThumbImage:thumbImage forState:UIControlStateNormal];
//滑块拖动时的事件
[sliderA addTarget:self action:@selector(sliderValueChanged:) forControlEvents:UIControlEventValueChanged];
//滑动拖动后的事件
[sliderA addTarget:self action:@selector(sliderDragUp:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:sliderA];
为了大家实验方便，我附上背景图brightness_bar.png和滑块图mark.png
http://pic002.cnblogs.com/images/2011/162291/2011121611431816.png
http://pic002.cnblogs.com/images/2011/162291/2011121611432897.png
-(IBAction)sliderValueChanged:(id)sender{
UISlider *slider = (UISlider *) sender;
NSString *newText = [[NSString alloc] initWithFormat:@”%d”, (int)(slider.value + 0.5f)];
label.text = newText;
}
- (IBActive) someButtonPressed:(id) sender
{
UIActionSheet *actionSheet = [[UIActionSheet alloc]
initWithTitle:@”Are you sure?”
delegate:self
cancelButtonTitle:@”No way!”
destructiveButtonTitle:@”Yes, I’m Sure!”
otherButtonTitles:nil];
[actionSheet showInView:self.view];
[actionSheet release];
}
- (void) actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger) buttonIndex
{
if(buttonIndex != [actionSheet cancelButtonIndex])
{
NSString *message = [[NSString alloc] initWithFormat:@”You can
breathe easy, everything went OK.”];
UIAlertView *alert = [[UIAlertView alloc]
initWithTitle:@”Something was done”
message:message
delegate:self
cancelButtonTitle:@”OK”
otherButtonTitles:nil];
[alert show];
[alert release];
[message release];
}
}
-(void)doChange:(id)sender
{
if(view2 == nil)
{
[self loadSec];
}
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:1];
[UIView setAnimationTransition:([view1
superview]?UIViewAnimationTransitionFlipFromLeft:UIViewAnimationTransitionFlipFromRight)forView:self.view
cache:YES];
if([view1 superview]!= nil)
{
[view1 removeFromSuperview];
[self.view addSubview:view2];
}else {
[view2 removeFromSuperview];
[self.view addSubview:view1];
}
[UIView commitAnimations];
}
Table View
#pragma mark -
#pragma mark Table View Data Source Methods
//指定分区中的行数，默认为1
- (NSInteger)tableView:(UITableView *)tableView
numberOfRowsInSection:(NSInteger)section
{
return [self.listData count];
}
//设置每一行cell显示的内容
- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *SimpleTableIndentifier = @"SimpleTableIndentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:SimpleTableIndentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleSubtitle
reuseIdentifier:SimpleTableIndentifier]
autorelease];
}
UIImage *image = [UIImage imageNamed:@"13.gif"];
cell.imageView.image = image;
NSUInteger row = [indexPath row];
cell.textLabel.text = [listData objectAtIndex:row];
cell.textLabel.font = [UIFont boldSystemFontOfSize:20];
if(row < 5)
cell.detailTextLabel.text = @"Best friends";
else
cell.detailTextLabel.text = @"friends";
return cell;
}
图像：如果设置图像，则它显示在文本的左侧； 文本标签：这是单元的主要文本（UITableViewCellStyleDefault 只显示文本标签）；详细文本标签：这是单元的辅助文本，通常用作解释性说明或标签
UITableViewCellStyleSubtitle
UITableViewCellStyleDefault
UITableViewCellStyleValue1
UITableViewCellStyleValue2
#pragma mark -
#pragma mark Table View Delegate Methods
//把每一行缩进级别设置为其行号
- (NSInteger)tableView:(UITableView *)tableView indentationLevelForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSUInteger row = [indexPath row];
return row;
}
//获取传递过来的indexPath值
- (NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSUInteger row = [indexPath row];
if (row == 0)
return nil;
return indexPath;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSUInteger row = [indexPath row];
NSString *rowValue = [listData objectAtIndex:row];
NSString *message = [[NSString alloc] initWithFormat:@"You selected %@",rowValue];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Row Selected"
message:message
delegate:nil
cancelButtonTitle:@"Yes, I did!"
otherButtonTitles:nil];
[alert show];
[alert release];
[message release];
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
//设置行的高度
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 40;
}
NavigationController推出push推出pop
[self.navigationController pushViewController:_detailController animated:YES];
[self.navigationController popViewControllerAnimated:YES];
Debug:
NSLog(@"%s %d", __FUNCTION__, __LINE__);
点击textField外的地方回收键盘
先定义一个UIControl类型的对象，在上面可以添加触发事件，令SEL实践为回收键盘的方法,最后将UIControl的实例加到当前View上。
UIControl *m_control = [[UIControl alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
[m_control addTarget:self action:@selector(keyboardReturn)
forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:m_control];
- (void) keyboardReturn
{
[aTextField resignFirstResponder];
}
当键盘调出时将输入框覆盖时，可以用下方法：
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField
{
[self.view setFrame:CGRectMake(0, -100, 320, 480) ];
return YES;
}
- (BOOL)textFieldShouldEndEditing:(UITextField *)textField
{
[self.view setFrame:CGRectMake(0, 0, 320, 480)];
return YES;
}
当准备输入时，将视图的位置上调100，这样键盘就不能覆盖到输入框。
当依赖注入方法不好使时，可以在AppDelegate内申明一个全局的控制器实例_anotherViewController，在另一个需要使用_anotherViewController的地方定义以下委托方法，使用共享的UIApplication实例来获取该委托的引用
SomeAppDelegate *appDelegate = (SomeAppDelegate *)[[UIApplication sharedApplication] delegate];
_anotherViewController = appDelegate._anotherViewController;
纯代码在UIViewController控制器内建Table View
@interfaceRootViewController : UIViewController {
NSArray *timeZoneNames;
}
@property (nonatomic,retain) NSArray *timeZoneNames;
(void) loadView
{
UITableView *tableView = [[UITableView alloc]
initWithFrame:[[UIScreen mainScreen] applicationFrame]] style:
UITableViewStylePlain];
tableView.autoresizingMask = (UIViewAutoresizingFlexibleHeight | UIViewAutoresizingWidth);
tableView.delegate = self;
tableView.dataSource = self;
[tableView reloadData];
self.view = tableView;
[tableView release];
}
NSString *thePath = [[NSBundle mainBundle] pathForResource:@"States" ofType:@"plist"];
NSArray *array = [NSArray arrayWithContentsOfFile:thePath];
手指的触摸范围：64X64
#pragma mark -
#pragma mark Touch Events
- (void)touchesBegan:(NSSet *) touches withEvent:(UIEvent *) event {
originFrame = bookCover.frame;
NSLog(@"%s %d", __FUNCTION__,__LINE__);
if ([touches count] == 2)
{
NSArray *twoTouches = [touches allObjects];
UITouch *firstTouch = [twoTouches objectAtIndex:0];
UITouch *secondTouch = [twoTouches objectAtIndex:1];
CGPoint firstPoint = [firstTouch locationInView:bookCover];
CGPoint secondPoint = [secondTouch locationInView:bookCover];
CGFloat deltaX = secondPoint.x - firstPoint.x;
CGFloat deltaY = secondPoint.y - firstPoint.y;
initialDistance = sqrt(deltaX * deltaX + deltaY * deltaY );
frameX = bookCover.frame.origin.x;
frameY = bookCover.frame.origin.y;
frameW = bookCover.frame.size.width;
frameH = bookCover.frame.size.height;
NSLog(@"%s %d", __FUNCTION__,__LINE__);
}
}
- (void)touchesMoved:(NSSet *) touches withEvent:(UIEvent *) event {
if([touches count] == 2)
{
NSLog(@"%s %d", __FUNCTION__,__LINE__);
NSArray *twoTouches = [touches allObjects];
UITouch *firstTouch = [twoTouches objectAtIndex:0];
UITouch *secondTouch = [twoTouches objectAtIndex:1];
CGPoint firstPoint = [firstTouch locationInView:bookCover];
CGPoint secondPoint = [secondTouch locationInView:bookCover];
CGFloat deltaX = secondPoint.x - firstPoint.x;
CGFloat deltaY = secondPoint.y - firstPoint.y;
CGFloat currentDistance = sqrt(deltaX * deltaX + deltaY * deltaY );
if (initialDistance == 0) {
initialDistance = currentDistance;
}
else if (currentDistance != initialDistance)
{
CGFloat changedDistance = currentDistance - initialDistance;
NSLog(@"changedDistance = %f",changedDistance);
[bookCover setFrame:CGRectMake(frameX - changedDistance / 2,
frameY - (changedDistance * frameH) / (2 * frameW),
frameW + changedDistance,
frameH + (changedDistance * frameH) / frameW)];
}
}
}
- (void)touchesEnded:(NSSet *) touches withEvent:(UIEvent *) event {
UITouch *touch = [touches anyObject];
UITouch双击图片变大/还原
if ([touch tapCount] == 2)
{
NSLog(@"%s %d", __FUNCTION__,__LINE__);
if (!flag) {
[bookCover setFrame:CGRectMake(bookCover.frame.origin.x - bookCover.frame.size.width / 2,
bookCover.frame.origin.y - bookCover.frame.size.height / 2,
2 * bookCover.frame.size.width,
2 * bookCover.frame.size.height)];
flag = YES;
}
else {
[bookCover setFrame:CGRectMake(bookCover.frame.origin.x +
bookCover.frame.size.width / 4, bookCover.frame.origin.y +
bookCover.frame.size.height / 4,
bookCover.frame.size.width / 2, bookCover.frame.size.height / 2)];
flag = NO;
}
}
}
(CGPoint)locationInView:(UIView *)view
(CGPoint)previousLocationInView:(UIView *)view
view window
tapCount(read only) timestamp(read only) phase(read only)
Getting a Touch Object's Gesture Recognizers
gestureRecognizers
UITouchPhaseBegan
UITouchPhaseMoved
UITouchPhaseStationary
UITouchPhaseEnded
UITouchPhaseCancelled
NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"book" ofType:@"plist"];
NSDictionary *dictionary = [[NSDictionary alloc] initWithContentsOfFile:plistPath];
NSString *book = [dictionary objectForKey:bookTitle];
[textView setText:book];
(void) initialize {
NSUserDefaults = [NSUserDefaults standardUserDefaults];
NSDictionary *appDefaults = [NSDictionary dictionaryWithObject:@"YES" forKey:@"DeleteBackup"];
[defaults registerDefaults:appDefaults];
}
To get a value of a default, use the valueForKey: method:
[[theDefaultsController values] valueForKey:@"userName"];
To set a value for a default, use setValue:forKey:
[[theDefaultsController values] setValue:newUserName forKey:@"userName"];
[[NSUserDefaults standardUserDefaults] setValue:aVale forKey:aKey];
[[NSUserDefaults standardUserDefaults] valueForKey:aKey];
NSArray *paths = NSSearchPathForDictionariesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filename = [documentsDirectory
stringByAppendingPathComponent:@"theFile.txt"];
NSString *tempPath = NSTemporaryDirectory();
NSString *tempFile = [tempPath stringByAppendingPathComponent:@"tempFile.txt"];
[[NSUserDefaults standardUserDefaults] setObject:data forKey:@"someKey"];
[[NSUserDefaults standardUserDefaults] objectForKey:aKey];
自定义NavigationBar
navigationBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
[navigationBar setBarStyle:UIBarStyleBlackOpaque];
myNavigationItem = [[UINavigationItem alloc] initWithTitle:@"Setting"];
[navigationBar setItems:[NSArray arrayWithObject:myNavigationItem]];
[self.view addSubview:navigationBar];
backButton = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonItemStylePlain target:self action:@selector(back)];
myNavigationItem.leftBarButtonItem = backButton;
NSURL *url = [NSURL URLWithString:@"http://www.cnblogs.com/tracy-e/"];
[[UIApplication sharedApplication] openURL:url];
webView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
[webView setDelegate:self];
[webView setScalesPageToFit:YES];
[webView setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight];
[webView setAllowsInlineMediaPlayback:YES];
[self.view addSubview:webView];
NSString *pdfPath = [[NSBundle mainBundle] pathForResource:@"ojc" ofType:@"pdf"];
NSURL *url = [NSURL fileURLWithPath:pdfPath];
NSURLRequest *request = [NSURLRequest requestWithURL:url
cachePolicy:NSURLRequestUseProtocolCachePolicy
timeoutInterval:5];
[webView loadRequest:request];
[myWebView loadRequest:[NSURLRequest requestWithURL:[NSURL
URLWithString: @"http://www.cnblogs.com/tracy-e/"]]];
NSString *errorString = [NSString stringWithFormat:@"
+5 color ='red'>An Error Occurred:
%@",error];
[myWebView loadHTMLString:errorString baseURL:nil];
//Stopping a load request when the view is to disappear
- (void)viewWillDisappear:(BOOL)animate{
if ([myWebView loading]){
[myWebView stopLoading];
}
myWebView.delegate = nil;
[UIApplication shareApplication].networkActivityIndicatorVisible = NO;
}
NSString *oriString = @"\\u67aa\\u738b";
NSString *escapedString = [oriString
stringByReplacingPercentEscapesUsingEncoding: NSUTF8StringEncoding];
Checking for background support on earlier versions of iOS
UIDevice *device = [UIDevice currentDevice];
BOOL backgroundSupported = NO;
if ([device respondsToSelector:@selector(isMultitaskingSupported)]){
backgroundSupported = device.multitaskingSupported;
}
Being a Responsible,Multitasking-Aware Application
# Do not make any OpenGL ES calls from your code.
# Cancel any Bonjour-related services before being suspended.
# Be prepared to handle connection failures in your network-based sockets.
# Save your application state before moving to the background.
# Release any unneeded memory when moving to the background.
# Stop using shared system resources before being suspended.
# Avoid updating your windows and views.
# Respond to connect and disconnect notification for external accessories.
# Clean up resource for active alerts when moving to the background.
# Remove sensitive information from views before moving to the background.
# Do minimal work while running in the background.
Handing the Keyboard notifications
//Call this method somewhere in your view controller setup code
- (void) registerForKeyboardNotifications{
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWasShown:)
name:UIKeyboardDidShowNotification
object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWasHidden:)
name:UIKeyboardDidHideNotification
object:nil];
}
//Called when the UIKeyboardDidShowNotification is sent
- (void)keyboardWasShown:(NSNotification *) aNotification{
if(keyboardShown)
return;
NSDictionary *info = [aNotification userInfo];
//get the size of the keyboard.
NSValue *aValue = [info objectForKey:UIKeyboardFrameBeginUserInfoKey];
CGSize keyboardSize = [aValue CGRectValue].size;
//Resize the scroll view
CGRect viewFrame = [scrollView frame];
viewFrame.size.height -= keyboardSize.height;
//Scroll the active text field into view
CGRect textFieldRect = [activeField frame];
[scrollView scrollRectToVisible:textFieldRect animated:YES];
keyboardShown = YES;
}
//Called when the UIKeyboardDidHideNotification is sent
- (void)keyboardWasHidden:(NSNotification *) aNotification{
NSDictionary *info = [aNotification userInfo];
//Get the size of the keyboard.
NSValue *aValue = [info objectForKey:UIKeyboardFrameEndUserInfoKey];
CGSize keyboardSize = [aValue CGRectValue].size;
//Reset the height of the scroll view to its original value
CGRect viewFrame = [scrollView Frame];
viewFrame.size.height += keyboardSize.height;
scrollView.frame = viewFrame;
keyboardShown = NO;
}
//首先给不同的textField赋不同的且相邻的tag值
- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
if ([textField returnKeyType] != UIReturnKeyDone)
{
NSInteger nextTag = [textField tag] + 1;
UIView *nextTextField = [[self tableView] viewWithTag:nextTag];
[nextTextField becomeFirstResponder];
}
else {
[textField resignFirstResponder];
}
return YES;
}
- (void)viewDidLoad {
[super viewDidLoad];
dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setGeneratesCalendarDates:YES];
[dateFormatter setLocale:[NSLocale currentLocale]];
[dateFormatter setCalendar:[NSCalendar autoupdatingCurrentCalendar]];
[dateFormatter setTimeZone:[NSTimeZone defaultTimeZone]];
[dateFormatter setDateStyle:NSDateFormatterShortStyle];
DOB.placeholder = [NSString stringWithFormat:@"Example: %@",[dateFormatter stringFromDate:[NSDate date]]];
}
- (void)textFieldDidEndEditing:(UITextField *)textField{
[textField resignFirstResponder];
if ([textField.text isEqualToString:@""])
return;
switch (textField.tag){
case DOBField:
NSDate *theDate = [dateFormatter dateFromString:textField.text];
if (theDate)
[inputDate setObject:theDate forKey:MyAppPersonDOBKey];
break;
default:
break;
}
}
tableView的cell高度除了在delegate中指定外，还可以在任意位置以[tableView setRowHeight:44]的方式指定
[[self navigationItem] setLeftBarButtonItem:[self editButtonItem]];
- (void)setEditing:(BOOL)editing animated:(BOOL)animated{
[super setEditing:editing animated:animated];
if (editing){
......
}
else{
......
}
}
One added a subview to a view, release the subview to avoid
the extra retain count of it, Because when you insert a view as a
subview using addSubview:, the subview is retained by its superview.
When you remove the subview from its superview using the
removeFromSuperview: method, subview is autoreleased.
在iPhone开发中,有时候我们想给导航条添加背景图片,实现多样化的导航条效果,用其他方法往往无法达到理想的效果,经过网上搜索及多次实验,确定如下最佳实现方案:
为UINavigatonBar增加如下Category(类别:提供一种为某个类添加方法而又不必编写子类的途径,类别只能添加成员函数，不能添加数据成员):
@implementation UINavigationBar (CustomImage)
- (void)drawRect:(CGRect)rect {
UIImage *image = [UIImage imageNamed: @"NavigationBar.png"];
[image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
}
@end
例如,在我的项目中,添加如下代码:
/////////////////////////////////////////////////////////
/* input: The image and a tag to later identify the view */
@implementation UINavigationBar (CustomImage)
- (void)drawRect:(CGRect)rect {
UIImage *image = [UIImage imageNamed: @"title_bg.png"];
[image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
}
@end
/////////////////////////////////////////////////////////
@implementation FriendsPageViewController
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
self.navigationBar.tintColor = [UIColor purpleColor];
[self initWithRootViewController:[[RegPageViewController alloc] init]];
[super viewDidLoad];
}
......
实现的效果如下图:
转载，原文地址http://blog.csdn.net/wave_1102/archive/2009/11/04/4768212.aspx
@implementation UINavigationBar (UINavigationBarCategory)
- (void)drawRect:(CGRect)rect {
//颜色填充
// UIColor *color = [UIColor redColor];
// CGContextRef context = UIGraphicsGetCurrentContext();
// CGContextSetFillColor(context, CGColorGetComponents( [color CGColor]));
// CGContextFillRect(context, rect);
// self.tintColor = color;
//图片填充
UIColor *color = [UIColor colorWithRed:46.0f/255.0f
green:87.0f/255.0f blue:29.0f/255.0f alpha:1.0f];
UIImage *img = [UIImage imageNamed: @"bg.png"];
[img drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
self.tintColor = color;
}
你还在使用myImage = [UIImage imageNamed:@"icon.png"]; 吗？
如题，是不是大家为了方便都这样加载图片啊
myImage = [UIImage imageNamed:@"icon.png"];
那么小心了
这种方法在一些图片很少，或者图片很小的程序里是ok的。
但是，在大量加载图片的程序里，请千万不要这样做。
为什么呢 ？？？？？？？
这种方法在application bundle的顶层文件夹寻找由供应的名字的图象。 如果找到图片，装载到iPhone系统缓存图象。那意味图片是(理论上)放在内存里作为cache的。
试想你图片多了，是什么后果？
图片cache极有可能不会响应memory warnings and release its objects
所以，用图片的时候一定要小心的alloc和release。
推荐使用NSString *path = [[NSBundle mainBundle] pathForResource:@"icon" ofType:@"png"];
myImage = [UIImage imageWithContentsOfFile:path];
// Todo use of myImage
[myImage release];
From:http://www.cocoachina.com/bbs/simple/?t27420.html
UIWebView *webView = [[UIWebView alloc]initWithFrame:CGRectMake(0, 55, 320, 300)];
webView.delegate = self;
webView.multipleTouchEnabled = YES;
webView.scalesPageToFit = YES;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *docPath = [documentsDirectory stringByAppendingString:@"/doc2003_1.doc"]; NSLog(@"#######%@",docPath);
NSURL *url = [NSURL fileURLWithPath:docPath];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[webView loadRequest:request];
[self.view addSubview:webView];
[webView release];
From:http://blog.csdn.net/dadalan/archive/2010/10/22/5959301.aspx
有时候在iPhone游戏中，既要播放背景音乐，同时又要播放比如枪的开火音效。此时您可以试试以下方法
NSString *musicFilePath = [[NSBundle mainBundle] pathForResource:fileName ofType:@"wav"]; //创建音乐文件路径
NSURL *musicURL = [[NSURL alloc] initFileURLWithPath:musicFilePath];
AVAudioPlayer* musicPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:musicURL error:nil];
[musicURL release];
[musicPlayer prepareToPlay];
//[musicPlayer setVolume:1]; //设置音量大小
//musicPlayer .numberOfLoops = -1;//设置音乐播放次数-1为一直循环
要导入框架AVFoundation.framework，头文件中#import ；做成类的话则更方便。
From:http://blog.csdn.net/dadalan/archive/2010/10/19/5950493.aspx
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(_willBecomeActive)
name:UIApplicationDidBecomeActiveNotification object:nil];
LOGO_320×44.png图片显示在背景上，
@implementation UINavigationBar (UINavigationBarCategory)
- (void)drawRect:(CGRect)rect {
//加入旋转坐标系代码
// Drawing code
UIImage *navBarImage = [UIImage imageNamed:@"LOGO_320×44.png"];
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(context, 0.0, self.frame.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
CGPoint center=self.center;
CGImageRef cgImage= CGImageCreateWithImageInRect(navBarImage.CGImage, CGRectMake(0, 0, 1, 44));
CGContextDrawImage(context, CGRectMake(center.x-160-80, 0, 80, self.frame.size.height), cgImage);
CGContextDrawImage(context, CGRectMake(center.x-160, 0, 320, self.frame.size.height), navBarImage.CGImage);
CGContextDrawImage(context, CGRectMake(center.x+160, 0, 80, self.frame.size.height), cgImage);
}
old code
CGContextDrawImage(context, CGRectMake(0, 0, self.frame.size.width, self.frame.size.height), navBarImage.CGImage);
hack过logo不再拉伸
From:http://blog.163.com/fengyi1103@126/blog/static/13835627420106279102671/
最近从通讯录读取电话号码，读出得号码如：134－1814－****。
而我需要的为11位纯数字，一直找方法解决此问题，今天终于找到了。。
分享一下……
代码如下：
NSString *originalString = @"(123) 123123 abc";
NSMutableString *strippedString = [NSMutableString
stringWithCapacity:originalString.length];
NSScanner *scanner = [NSScanner scannerWithString:originalString];
NSCharacterSet *numbers = [NSCharacterSet
characterSetWithCharactersInString:@"0123456789"];
while ([scanner isAtEnd] == NO) {
NSString *buffer;
if ([scanner scanCharactersFromSet:numbers intoString:&buffer]) {
[strippedString appendString:buffer];
}
// --------- Add the following to get out of endless loop
else {
[scanner setScanLocation:([scanner scanLocation] + 1)];
}
// --------- End of addition
}
NSLog(@"%@", strippedString); // "123123123"
From：http://stackoverflow.com/questions/1129521/remove-all-but-numbers-from-nsstring
NSString *mystring = @"Letter1234";
NSString *regex = @"[a-z][A-Z][0-9]";
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
if ([predicate evaluateWithObject:mystring] == YES) {
//implement
}
UITableView的cell默认出现在uitableview的第一行，如果你想自定义UITableViewCell与导航条间距的话，可以使用下面这行代码
tableview.tableHeaderView = [[[UIView alloc] initWithFrame:CGRectMake(0, 0, 5, 20)]autorelease];
From:http://blog.163.com/fengyi1103@126/blog/static/1383562742010101611107492/
UITableview的滚动条默认颜色是黑色的，如果UItableview背景也是深颜色，则滚动条会变的很不明显。您可以用下面这行代码来改变滚动条的颜色
self.tableView.indicatorStyle=UIScrollViewIndicatorStyleWhite;
当然，最后的 “White” 也可以换成其它颜色。
下面这段代码，能实现在下载文件之前获得文件大小，应用在软件里，能在很大程度上改善用户体验
[m_pASIHTTPRequest setDidReceiveResponseHeadersSelector:@selector(didReceiveResponseHeaders:)];
- (void)didReceiveResponseHeaders:(ASIHTTPRequest *)request
{
NSLog(@"didReceiveResponseHeaders %@",[m_request.responseHeaders valueForKey:@"Content-Length"]);
｝
一：确认网络环境3G/WIFI
1.添加源文件和framework
开发Web等网络应用程序的时候，需要确认网络环境，连接情况等信息。如果没有处理它们，是不会通过Apple的审(我们的)查的。
Apple的 例程Reachability中介绍了取得/检测网络状态的方法。要在应用程序程序中使用Reachability，首先要完成如下两部：
1.1.添加源文件：
在你的程序中使用Reachability只须将该例程中的Reachability.h和Reachability.m拷贝到你的工程中。如下图：
1.2.添加framework：
将SystemConfiguration.framework添加进工程。如下图：
2.网络状态
Reachability.h中定义了三种网络状态：
typedef enum {
NotReachable = 0, //无连接
ReachableViaWiFi, //使用3G/GPRS网络
ReachableViaWWAN //使用WiFi网络
} NetworkStatus;
因此可以这样检查网络状态：
Reachability *r = [Reachability reachabilityWithHostName:@“www.apple.com”];
switch ([r currentReachabilityStatus]) {
case NotReachable:
//没有网络连接
break;
case ReachableViaWWAN:
//使用3G网络
break;
case ReachableViaWiFi:
//使用WiFi网络
break;
}
3.检查当前网络环境
程序启动时，如果想检测可用的网络环境，可以像这样
//是否wifi
+ (BOOL) IsEnableWIFI {
return ([[Reachability reachabilityForLocalWiFi] currentReachabilityStatus] != NotReachable);
}
//是否3G
+ (BOOL) IsEnable3G {
return ([[Reachability reachabilityForInternetConnection] currentReachabilityStatus] != NotReachable);
}
例子：
- (void)viewWillAppear:(BOOL)animated {
if (([Reachability reachabilityForInternetConnection].currentReachabilityStatus == NotReachable) &&
([Reachability reachabilityForLocalWiFi].currentReachabilityStatus == NotReachable)) {
self.navigationItem.hidesBackButton = YES;
[self.navigationItem setLeftBarButtonItem:nil animated:NO];
}
}
[mySearchBar release];
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