iOS 笔记

1.配置全局为中文，例如输入框弹出“全选”

打开 info.plist 将Localization native development region 设置为china ；选择project 点击 info 在 localizations 添加 Chinese(Simplified)

2.节约内存读取本地文件

NSMutableData *data = [NSMutableDatadataWithContentsOfFile:fileName options:NSDataReadingMappedIfSafeerror:&error];

3.调整图片大小

//调整图片大小

+(UIImage *)scaleImage:(UIImage *)image toScale:(float)scaleSize

{

    UIGraphicsBeginImageContext(CGSizeMake(image.size.width*scaleSize,image.size.height*scaleSize));

    [image drawInRect:CGRectMake(0,0, image.size.width * scaleSize, image.size.height *scaleSize)];

    UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return scaledImage;

}

或者：

UIImage *images = [imagefixOrientation];

NSData *imageData = UIImageJPEGRepresentation(images, 0.3);

4.获取当前时间

//获取当前时间根据自定义格式，例如yyyy-MM-dd HH:mm:ss

+(NSString*)getCurrentTimeWithTimaFormat:(NSString *)timeFormat{

    NSDateFormatter *dateformat=[[NSDateFormatter alloc]init];

    [dateformat setDateFormat:timeFormat];

    NSString *currentTime = [dateformatstringFromDate:[NSDatedate]];

    [dateformat release];

    return currentTime;

}

 

5.设置navigationbar

    [self.navigationController.navigationBarsetTitleTextAttributes:[NSDictionarydictionaryWithObjectsAndKeys:[UIColorwhiteColor],UITextAttributeTextColor, [UIColorcolorWithRed:0.0green:0.0 blue:0.0 alpha:0.0],UITextAttributeTextShadowColor,[UIFontsystemFontOfSize:17],UITextAttributeFont,nil]];

[self.navigationController.navigationBarsetBackgroundImage:[UIImageimageNamed:@"lclNavbar_black.png"]forBarMetrics:UIBarMetricsDefault];

 

6.设置statusbar

    [[UIApplication sharedApplication]setStatusBarStyle:UIStatusBarStyleLightContent];

将 View controller-based status barappearance 设为 NO

 

7.强制转换为arc   ： -fobjc-arc

 

8.设置边框阴影

    self.lclImageViewHeadBack.layer.shadowColor = [UIColorblackColor].CGColor;

    self.lclImageViewHeadBack.layer.shadowOffset =CGSizeMake(-1.0,1.0);

    self.lclImageViewHeadBack.layer.shadowOpacity =0.8;

self.lclImageViewHeadBack.layer.shadowRadius =2.0;

 

9.监听键盘通知

    [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(keyboardWillShow:)

                                                name:UIKeyboardWillShowNotificationobject:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(keyboardShow:)

                                                name:UIKeyboardDidShowNotification object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(keyboardWillHide:)

                                                name:UIKeyboardWillHideNotificationobject:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(keyboardHide:)

                                                name:UIKeyboardDidHideNotification object:nil];

10. 沙盒存储/缓存路径

//NSString*tempPath = NSTemporaryDirectory();

    //NSArray*cacPathArray =NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES);//library

    //NSArray *cacPathArray =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES); //Documents

    NSArray *cacPathArray = NSSearchPathForDirectoriesInDomains(NSCachesDirectory,NSUserDomainMask, YES); //cache

NSString *fileDir = [cacPathArrayobjectAtIndex:0];

 

11. 截屏

   +(NSData*)getScreenImageFromView:(UIView *)view{

    UIGraphicsBeginImageContext(view.bounds.size);

    [view.layer renderInContext:UIGraphicsGetCurrentContext()];

    UIImage *image=UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    NSData *imageData = UIImageJPEGRepresentation(image, 0.3);

    return imageData;

}

 

12. GCD 线程

dispatch_queue_t downloadQueue = dispatch_queue_create("lcl downloader",NULL);

dispatch_async(downloadQueue, ^{

   dispatch_async(dispatch_get_main_queue(), ^{

    });

});

dispatch_release(downloadQueue); //won’t actually go away until queue is empty

 

13. 本地文件处理：复制 删除 重命名

    NSFileManager*fileManager = [NSFileManagerdefaultManager];

创建本地文件夹：[fileManager createDirectoryAtPath:namewithIntermediateDirectories:YESattributes:nilerror:nil];

创建本地文件： [fileManager createFileAtPath:namecontents:nilattributes:nil];

重命名：[fileManager moveItemAtPath:[[self.copysFileArrayobjectAtIndex:i] objectForKey:LCLFileURL]toPath:[NSStringstringWithFormat:@"%@%@",self.currentFolderPath,name]error:&error]

删除：[fileManager removeItemAtPath:[[self.copysFileArrayobjectAtIndex:i] objectForKey:LCLFileURL]error:nil];

 

14. scrollview 放大图片

- (UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView

{

    for (id viewin [scrollView subviews]) {

        if ([view isKindOfClass:[UIImageView class]]) {

            return view;

        }

    }

    return  nil;

}

 

15.多参数传值

- (IBAction)showLCLActionSheetOnView:(UIView *)view otherButtonTitles:(NSString *)otherButtonTitles, ...NS_REQUIRES_NIL_TERMINATION{

    UIActionSheet * actionSheet = [[UIActionSheetalloc]init];

    int i=0;

    va_list args;

    // scan for arguments afterotherButtonTitles.

    va_start(args, otherButtonTitles);

    // get rest of the objects until nil isfound

    for (NSString *str = otherButtonTitles;str !=nil; str = va_arg(args,NSString*)) {

        [actionSheet addButtonWithTitle:str];

        i++;

    }

    va_end(args);

    [actionSheet addButtonWithTitle:@"取消"];

    [actionSheet setCancelButtonIndex:i];

    [actionSheet setDelegate:self];

    actionSheet.actionSheetStyle =UIActionSheetStyleBlackTranslucent;

    [actionSheet showInView:view];

    [actionSheet release];

}

 

16. JSON 字符串转data

NSData* plistData =[message dataUsingEncoding:NSUTF8StringEncoding];

 

17. itunes 传输文件到app

设置 Application supports iTunes filesharing 为 YES

 

18. openfire 插件编译

进入build路径：/Users/lcl/Documents/workspace/openfire_src/build

编译所有插件

ant plugin

编译指定插件

ant plugin-Dplugin=SamplePlugin

 

19. id 转为json 字符串

    NSString *str = nil;

    if ([NSJSONSerializationisValidJSONObject:self.addPeopleArrray]){

        NSError *error;

        // 创造一个json从Data,NSJSONWritingPrettyPrinted指定的JSON数据产的空白，使输出更具可读性。

        NSData *jsonData = [NSJSONSerializationdataWithJSONObject:self.addPeopleArrrayoptions:NSJSONWritingPrettyPrintederror:&error];

        str =[[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];

        NSLog(@"json data:%@",str);

    }