iOS必备知识

1获取系统语言设置

NSUserDefaults *userDefault = [NSUserDefaults standardUserDefaults];

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

NSString *preferredLang = [languages objectAtIndex:0];

2缓存路径下文件大小

- (unsigned long long int) cacheFolderSize

{

NSFileManager *_manager = [NSFileManager defaultManager];

NSArray *_cachePaths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory,

NSUserDomainMask, YES);

NSString *_cacheDirectory = [_cachePaths objectAtIndex:];

NSArray *_cacheFileList;

NSEnumerator *_cacheEnumerator;

NSString *_cacheFilePath;

unsigned long long int _cacheFolderSize = ;

_cacheFileList = [ _manager subpathsAtPath:_cacheDirectory];

_cacheEnumerator = [_cacheFileList objectEnumerator];

while (_cacheFilePath = [_cacheEnumerator nextObject])

{

NSDictionary *_cacheFileAttributes = [_managerfileAttributesAtPath:

[_cacheDirectory stringByAppendingPathComponent:_cacheFilePath]

traverseLink:YES];

_cacheFolderSize += [_cacheFileAttributes fileSize];

}

// 单位是字节

return _cacheFolderSize;

}

3Popover push 时 Frame无法改变解决办法

在popover中的ViewController中实现：

- (void)viewWillAppear:(BOOL)animated

{

CGSize size = CGSizeMake(320, 480); // size of view in popover

self.contentSizeForViewInPopover = size;

[super viewWillAppear:animated];

}

4SFHFKeychainUtils 存储信息

苹果SDK自带的就有密码保护，使用方法很简单，如下：

1、引入Security.frameWork框架。

2、引入头文件：SFHKeychainUtils.h.

3、存密码：

[SFHFKeychainUtils storeUsername:@"dd" andPassword:@"aa"forServiceName:SERVICE_NAMEupdateExisting:1 error:nil];

[SFHFKeychainUtils deleteItemForUsername:@"dd" andServiceName:SERVICE_NAME error:nil];

4、取密码：

NSString *passWord = [SFHFKeychainUtils getPasswordForUsername:@"dd"andServiceName:SERVICE_NAMEerror:nil];

5missing required architecture i386 in file 解决办法

在TargetInfo里面修改 Framework Search Pasths 删除里面内容就可以了。

6view 放大缩小动画效果

//创建缩小了的视图

myWeiBoImageVC = [[UIViewController alloc] init];

myWeiBoImageVC.view.clipsToBounds = YES;

myWeiBoImageVC.view.alpha = 0.0;

myWeiBoImageVC.view.frame = CGRectMake(64, 0, 1024-64, 768-20);

[self.view addSubview:myWeiBoImageVC.view];

CGAffineTransform newTransform =

CGAffineTransformScale(myWeiBoImageVC.view.transform, 0.1, 0.1);

[myWeiBoImageVC.view setTransform:newTransform];

myWeiBoImageVC.view.center = CGPointMake(670, 100);

[self performSelector:@selector(imageViewControllerBigAnimation)];

//放大刚刚创建缩小后的视图

- (void)imageViewControllerBigAnimation{

[UIView beginAnimations:@"imageViewBig" context:nil];

[UIView setAnimationDuration:0.5];

CGAffineTransform newTransform = CGAffineTransformConcat(myWeiBoImageVC.view.transform, CGAffineTransformInvert(myWeiBoImageVC.view.transform));

[myWeiBoImageVC.view setTransform:newTransform];

myWeiBoImageVC.view.alpha = 1.0;

myWeiBoImageVC.view.center = CGPointMake(416, 510)；

[UIView commitAnimations];

}

//缩小视图隐藏

- (void)imageViewControllerSmallAnimation{

[UIView beginAnimations:@"imageViewSmall" context:nil];

[UIView setAnimationDuration:0.5];

CGAffineTransform newTransform = CGAffineTransformScale(myWeiBoImageVC.view.transform, 0.1, 0.1);

[myWeiBoImageVC.view setTransform:newTransform];

myWeiBoImageVC.view.center = CGPointMake(670, 100);

[UIView commitAnimations];

}

7、给View添加阴影和边框

UIImageView *imgvPhoto = [UIImageView alloc] init];

//添加边框

CALayer *layer = [_imgvPhoto layer];

layer.borderColor = [[UIColor whiteColor] CGColor];

layer.borderWidth = 5.0f;

//添加四个边阴影

_imgvPhoto.layer.shadowColor = [UIColor blackColor].CGColor;

_imgvPhoto.layer.shadowOffset = CGSizeMake(0, 0);

_imgvPhoto.layer.shadowOpacity = 0.5;

_imgvPhoto.layer.shadowRadius = 10.0;

//添加两个边阴影

_imgvPhoto.layer.shadowColor = [UIColor blackColor].CGColor;

_imgvPhoto.layer.shadowOffset = CGSizeMake(4, 4);

_imgvPhoto.layer.shadowOpacity = 0.5;

_imgvPhoto.layer.shadowRadius = 2.0;

8、使用NSTimer与UIView动画实现飘雪效果

viewDidLoad事件中，增加一个图片及定时器并启动,这里的pic请在头文件中定义。

-(void)viewDidLoad{

[super viewDidLoad];

self.pic = [UIImage imageNamed:@"snow.png"];//初始化图片

//启动定时器，实现飘雪效果

[NSTimer scheduledTimerWithTimeInterval:(0.2) target:self selector:@selector(ontime) userInfo:nil repeats:YES];

}

然后再实现定时器定时调用的ontime方法：

-(void)ontime{

UIImageView *view = [[UIImageView alloc] initWithImage:pic];//声明一个UIImageView对象，用来添加图片

view.alpha = 0.5;//设置该view的alpha为0.5，半透明的

int x = round(random()20);//随机得到该图片的x坐标

int y = round(random()20);//这个是该图片移动的最后坐标x轴的

int s = round(random())+10;//这个是定义雪花图片的大小

int sp = 1/round(random()0)+1;//这个是速度

view.frame = CGRectMake(x, -50, s, s);//雪花开始的大小和位置

[self.view addSubview:view];//添加该view

[UIView beginAnimations:nil context:view];//开始动画

[UIView setAnimationDuration:10*sp];//设定速度

view.frame = CGRectMake(y, 500, s, s);//设定该雪花最后的消失坐标

[UIView setAnimationDelegate:self];

[UIView commitAnimations];

}

9、ASIHTTPRequest实现断点下载

- (IBAction)URLFetchWithProgress:(id)sender

{

[startButton setTitle:@"Stop" forState:UIControlStateNormal];

[startButton addTarget:self action:@selector(stopURLFetchWithProgress:)forControlEvents:UIControlEventTouchUpInside];

NSString*tempFile = [[[[NSBundle mainBundle] bundlePath]stringByDeletingLastPathComponent]stringByAppendingPathComponent:@"MemexTrails_1.0b1.zip.download"];

if ([[NSFileManager defaultManager] fileExistsAtPath:tempFile]) {

[[NSFileManager defaultManager] removeItemAtPath:tempFile error:nil];

}

[self resumeURLFetchWithProgress:self];

}

- (IBAction)stopURLFetchWithProgress:(id)sender

{

networkQueue = [[ASINetworkQueue alloc] init];

timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:selfselector:@selector(updateBandwidthUsageIndicator) userInfo:nil repeats:YES];

timer = nil;

[startButton setTitle:@"Stop" forState:UIControlStateNormal];

[startButton addTarget:self action:@selector(URLFetchWithProgress:)forControlEvents:UIControlEventTouchUpInside];

[networkQueue cancelAllOperations];

[resumeButton setEnabled:YES];

}

- (IBAction)resumeURLFetchWithProgress:(id)sender

{

[resumeButton setEnabled:NO];

[startButton setTitle:@"Start" forState:UIControlStateNormal];

[startButton addTarget:self action:@selector(stopURLFetchWithProgress:)forControlEvents:UIControlEventTouchUpInside];

[networkQueue cancelAllOperations];

[networkQueue setShowAccurateProgress:YES];

[networkQueue setDownloadProgressDelegate:progressIndicator];

[networkQueue setDelegate:self];

[networkQueue setRequestDidFinishSelector:@selector(URLFetchWithProgressComplete:)];

ASIHTTPRequest*request=[[[ASIHTTPRequest alloc] initWithURL:[NSURLURLWithString:@"http://9991.net/blog/mp3/2.mp3"]] autorelease];

[request setDownloadDestinationPath:[[[[NSBundle mainBundle] bundlePath]

stringByDeletingLastPathComponent] stringByAppendingPathComponent:@"MemexTrails_1.0b1.mp3"]];

[request setTemporaryFileDownloadPath:[[[[NSBundle mainBundle] bundlePath]stringByDeletingLastPathComponent]stringByAppendingPathComponent:@"MemexTrails_1.0b1.zip.down"]];

[request setAllowResumeForFileDownloads:YES];

[networkQueue addOperation:request];

[networkQueue go];

}

- (void)URLFetchWithProgressComplete:(ASIHTTPRequest *)request

{

if ([request error]) {

fileLocation.text=[NSString stringWithFormat:@"An error occurred:%@",[[[requesterror] userInfo] objectForKey:@"Title"]];

} else {

fileLocation.text=[NSString stringWithFormat:@"File downloaded to %@",[requestdownloadDestinationPath]];

}

[startButton setTitle:@"Start" forState:UIControlStateNormal];

[startButton addTarget:self action:@selector(URLFetchWithProgress:)forControlEvents:UIControlEventTouchUpInside];

}

- (IBAction)throttleBandwidth:(id)sender

{

if ([(UIButton *)sender state] ==YES) {

[ASIHTTPRequest setMaxBandwidthPerSecond:ASIWWANBandwidthThrottleAmount];

} else {

[ASIHTTPRequest setMaxBandwidthPerSecond:];

}

10、CoreText 总结

（1） NSAttributedString

NSAttributedString 可以将一段文字中的部分文字设置单独的字体和颜色。

与UITouch结合可以实现点击不同文字触发不同事件的交互功能。

主要方法：

- (void)addAttribute:(NSString *)name value:(id)value range:(NSRange)range;

可以设置某段文字的字体名称，颜色，下滑线等信息。

- (void)removeAttribute:(NSString *)name range:(NSRange)range;

移除之前设置的字体属性值。

- (void)addAttributes:(NSDictionary *)attrs range:(NSRange)range;

存储某段文字包含的信息（包括字体属性或其它，也可以存储一些自定义的信息）

- (NSDictionary *)attributesAtIndex:(NSUInteger)location effectiveRange:(NSRangePointer)range;

通过location来获取某段文字中之前存储的信息NSDictionary

//设置字体

CTFontRef aFont = CTFontCreateWithName((CFStringRef)textFont.fontName, textFont.pointSize, NULL);

if (!aFont) return;

CTFontRef newFont = CTFontCreateCopyWithSymbolicTraits(aFont, 0.0, NULL, kCTFontItalicTrait, kCTFontBoldTrait); //将默认黑体字设置为其它字体

[self removeAttribute:(NSString*)kCTFontAttributeName range:textRange];

[self addAttribute:(NSString*)kCTFontAttributeName value:(id)newFont range:textRange];

CFRelease(aFont);

CFRelease(newFont);

//设置字体颜色

[self removeAttribute:(NSString*)kCTForegroundColorAttributeName range:textRange];

[self addAttribute:(NSString*)kCTForegroundColorAttributeName value:(id)textColor.CGColor range:textRange];

//设置对齐换行

CTTextAlignment coreTextAlign = kCTLeftTextAlignment;

CTLineBreakMode coreTextLBMode = kCTLineBreakByCharWrapping;

CTParagraphStyleSetting paraStyles[2] =

{

{.spec = kCTParagraphStyleSpecifierAlignment, .valueSize = sizeof(CTTextAlignment), .value = (const void*)&coreTextAlign},

{.spec = kCTParagraphStyleSpecifierLineBreakMode, .valueSize = sizeof(CTLineBreakMode), .value = (const void*)&coreTextLBMode},

};

CTParagraphStyleRef aStyle = CTParagraphStyleCreate(paraStyles, 2);

[self removeAttribute:(NSString*)kCTParagraphStyleAttributeName range:textRange];

[self addAttribute:(NSString*)kCTParagraphStyleAttributeName value:(id)aStyle range:textRange];

CFRelease(aStyle);

（2）Draw NSAttributedString

CGContextRef cgc = UIGraphicsGetCurrentContext();

CGContextSaveGState(cgc);

//图像方向转换

CGContextConcatCTM(cgc, CGAffineTransformScale(CGAffineTransformMakeTranslation(0, self.bounds.size.height), 1.f, -1.f));

CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)weiBoText);

drawingRect = self.bounds;

CGMutablePathRef path = CGPathCreateMutable();

CGPathAddRect(path, NULL, drawingRect);

textFrame = CTFramesetterCreateFrame(framesetter,CFRangeMake(0,0), path, NULL);

CGPathRelease(path);

CFRelease(framesetter);

CTFrameDraw(textFrame, cgc);

CGContextRestoreGState(cgc);

（3）图文混排

CTFrameRef textFrame // coreText 的 frame

CTLineRef line // coreText 的 line

CTRunRef run // line 中的部分文字

iOS必备知识

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