iOS开发中一些常用的方法

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mob604756f44f2a 2016-09-19 13:53:00

文章标签 webview ico lua ide #define 文章分类 iOS 移动开发

1.压缩图片

[objc] view plain copy

#pragma mark 处理图片
- (void)useImage:(UIImage *)image
{
NSLog(@"with-----%f heught-----%f",image.size.width,image.size.height);
float scales = image.size.height / image.size.width; //图片比例
NSLog(@"图片比例：%f",scales);
UIImage * normalImg;
if (image.size.width >300 || image.size.height > 300) {
if (scales > 1) {
normalImg = [self imageWithImageSimple:image scaledToSize:CGSizeMake(300 / scales, 300)];
}else {
normalImg = [self imageWithImageSimple:image scaledToSize:CGSizeMake(300 ,3300 * scales)];
}
}
else {
normalImg = image;
}
NSLog(@"第一次处理后：with-----%f height-----%f",normalImg.size.width, normalImg.size.height);
CGSize newSize = CGSizeMake(normalImg.size.width, normalImg.size.height);
float kk = 1.0f;//图片压缩系数
int mm;//压缩后的大小
float aa = 1.0f;//图片压缩系数变化步长(可变)
mm = (int)UIImageJPEGRepresentation(normalImg, kk).length;
while (mm / 1024 > 300) {
if (kk > aa + aa / 10) {
kk -= aa;
if (mm == (int)UIImageJPEGRepresentation(normalImg, kk).length) {
break;
}
mm = (int)UIImageJPEGRepresentation(normalImg, kk).length;
}else{
aa /= 10;
}
}
NSLog(@"KK:%f -- aa:%f",kk,aa);
#warning 图片压缩
NSLog(@"第二次处理后：with-----%f height-----%f",normalImg.size.width, normalImg.size.height);
NSData *newData;
newData = UIImageJPEGRepresentation(normalImg, kk);//最后压缩结果
if (newData.length/1024 > 300) {
[APPRequest showAlert:@"提示" message:@"图片过大"];
}else{
// 上传图片网络请求
}
}];
}
}

2.发布时间

[objc] view plain copy

NSDate * timeDate = [NSDate date];
NSTimeInterval nowInt = [timeDate timeIntervalSince1970]*1;
NSDateFormatter *dateformatter=[[NSDateFormatter alloc] init];
[dateformatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
NSDate* publishDate = [dateformatter dateFromString:[demandlist.publish_time substringToIndex:19]];
NSTimeInterval publishInt = [publishDate timeIntervalSince1970]*1;
NSTimeInterval cha = nowInt - publishInt;
NSString *timeString=@"";
if (cha/3600<1) {
timeString = [NSString stringWithFormat:@"%f", cha/60];
timeString = [timeString substringToIndex:timeString.length-7];
timeString = [NSString stringWithFormat:@"%@分钟前发布", timeString];
}
if (cha/3600>1&&cha/86400<1) {
timeString = [NSString stringWithFormat:@"%f", cha/3600];
timeString = [timeString substringToIndex:timeString.length-7];
timeString = [NSString stringWithFormat:@"%@小时前发布", timeString];
}
if (cha/86400>1)
{
timeString = [NSString stringWithFormat:@"%f", cha/86400];
timeString = [timeString substringToIndex:timeString.length-7];
timeString = [NSString stringWithFormat:@"%@天前发布", timeString];
}

3.返回字符串所占的尺寸

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//返回字符串所占用的尺寸.
-(CGSize)sizeWithFont:(UIFont *)font maxSize:(CGSize)maxSize
{ NSDictionary *attrs = @{NSFontAttributeName : font};
return [self boundingRectWithSize:maxSize options:NSStringDrawingUsesLineFragmentOrigin attributes:attrs context:nil].size;
}

4.tableView自动滑倒某一行

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NSIndexPath *scrollIndexPath = [NSIndexPath indexPathForRow:10 inSection:0];
[[self tableView] scrollToRowAtIndexPath:scrollIndexPath
atScrollPosition:UITableViewScrollPositionTop animated:YES];

5.tableView刷新某个分区或某行

[objc] view plain copy

NSIndexSet *indexSet=[[NSIndexSet alloc]initWithIndex:2];
[tableview reloadSections:indexSet withRowAnimation:UITableViewRowAnimationAutomatic];
//一个cell刷新
NSIndexPath *indexPath=[NSIndexPath indexPathForRow:3 inSection:0];
[tableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:indexPath,nil] withRowAnimation:UITableViewRowAnimationNone]; <span style="font-family: Arial, Helvetica, sans-serif;"> </span>

6.读取plist文件

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NSString *plistPath = [[NSBundle mainBundle] pathForResource:@"plistdemo" ofType:@"plist"];
NSMutableDictionary *data = [[NSMutableDictionary alloc] initWithContentsOfFile:plistPath];

7.关键字高亮

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label.text = [NSString stringWithFormat:@" 视野头条:%@",home.title];
NSString *str = [NSString stringWithFormat:@" 视野头条:%@",home.title];
NSMutableAttributedString *titleStr = [[NSMutableAttributedString alloc]initWithString:str];
NSRange range = [str rangeOfString:@"视野头条:"];
[titleStr addAttribute:NSForegroundColorAttributeName value:[UIColor orangeColor] range:range];
[label setAttributedText:titleStr];

8.去掉字符串中的空格

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NSString *str = @"dhak d sh akdl ";
NSString *strUrl = [str stringByReplacingOccurrencesOfString:@" " withString:@""];

9.UIImage添加生成圆角图片的扩展API

[objc] view plain copy

给UIImage添加生成圆角图片的扩展API：
- (UIImage *)imageWithCornerRadius:(CGFloat)radius {
CGRect rect = (CGRect){0.f, 0.f, self.size};
UIGraphicsBeginImageContextWithOptions(self.size, NO, UIScreen.mainScreen.scale);
CGContextAddPath(UIGraphicsGetCurrentContext(),
[UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:radius].CGPath);
CGContextClip(UIGraphicsGetCurrentContext());
[self drawInRect:rect];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
//然后调用时就直接传一个圆角来处理：
imgView.image = [[UIImage imageNamed:@"test"] hyb_imageWithCornerRadius:4];
//最直接的方法就是使用如下属性设置：
imgView.layer.cornerRadius = 10;
// 这一行代码是很消耗性能的
imgView.clipsToBounds = YES;
// 好处是使用简单，操作方便。坏处是离屏渲染（off-screen-rendering）需要消耗性能。对于图片比较多的视图上，不建议使用这种方法来设置圆角。通常来说，计算机系统中CPU、GPU、显示器是协同工作的。CPU计算好显示内容提交到GPU，GPU渲染完成后将渲染结果放入帧缓冲区。
//简单来说，离屏渲染，导致本该GPU干的活，结果交给了CPU来干，而CPU又不擅长GPU干的活，于是拖慢了UI层的FPS（数据帧率），并且离屏需要创建新的缓冲区和上下文切换，因此消耗较大的性能。

10.正则法则

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//1.验证邮箱
+ (BOOL)validateEmail:(NSString *)email
{
NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";
NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];
return [emailTest evaluateWithObject:email];
}
//2.验证手机（简单的）
+ (BOOL)validatePhone:(NSString *)phone
{
NSString *phoneRegex = @"1[3|5|7|8|][0-9]{9}";
NSPredicate *phoneTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", phoneRegex];
return [phoneTest evaluateWithObject:phone];
}
//验证手机（复杂的）
+ (BOOL)validatePhone:(NSString *)phone
{
/**
* 手机号码
* 移动：134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188
* 联通：130,131,132,152,155,156,185,186
* 电信：133,1349,153,180,189
*/
NSString * MOBILE = @"^1(3[0-9]|5[0-35-9]|8[025-9])\\d{8}$";
/**
10 * 中国移动：China Mobile
11 * 134[0-8],135,136,137,138,139,150,151,157,158,159,182,187,188
12 */
NSString * CM = @"^1(34[0-8]|(3[5-9]|5[017-9]|8[278])\\d)\\d{7}$";
/**
15 * 中国联通：China Unicom
16 * 130,131,132,152,155,156,185,186
17 */
NSString * CU = @"^1(3[0-2]|5[256]|8[56])\\d{8}$";
/**
20 * 中国电信：China Telecom
21 * 133,1349,153,180,189
22 */
NSString * CT = @"^1((33|53|8[09])[0-9]|349)\\d{7}$";
/**
25 * 大陆地区固话及小灵通
26 * 区号：010,020,021,022,023,024,025,027,028,029
27 * 号码：七位或八位
28 */
// NSString * PHS = @"^0(10|2[0-5789]|\\d{3})\\d{7,8}$";
NSPredicate *regextestmobile = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", MOBILE];
NSPredicate *regextestcm = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CM];
NSPredicate *regextestcu = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CU];
NSPredicate *regextestct = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", CT];
if (([regextestmobile evaluateWithObject:phone] == YES)
|| ([regextestcm evaluateWithObject:phone] == YES)
|| ([regextestct evaluateWithObject:phone] == YES)
|| ([regextestcu evaluateWithObject:phone] == YES))
{
if([regextestcm evaluateWithObject:phone] == YES) {
NSLog(@"China Mobile");
} else if([regextestct evaluateWithObject:phone] == YES) {
NSLog(@"China Telecom");
} else if ([regextestcu evaluateWithObject:phone] == YES) {
NSLog(@"China Unicom");
} else {
NSLog(@"Unknow");
}
return YES;
}
else
{
return NO;
}
}

11.清除缓存

[objc] view plain copy

// 删除缓存
- (void)removeCache
{
NSString *cachePath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) lastObject];
NSLog(@"%@",cachePath);
NSArray *files = [[NSFileManager defaultManager] subpathsAtPath:cachePath];
for (NSString *p in files) {
NSString *path = [NSString stringWithFormat:@"%@/%@", cachePath, p];
if ([[NSFileManager defaultManager] fileExistsAtPath:path]) {
[[NSFileManager defaultManager] removeItemAtPath:path error:nil];
}
}
}
// 计算清除的缓存大小
- (CGFloat)floatWithPath:(NSString *)path
{
CGFloat num = 0;
NSFileManager *man = [NSFileManager defaultManager];
if ([man fileExistsAtPath:path]) {
NSEnumerator *childFile = [[man subpathsAtPath:path] objectEnumerator];
NSString *fileName;
while ((fileName = [childFile nextObject]) != nil) {
NSString *fileSub = [path stringByAppendingPathComponent:fileName];
num += [self fileSizeAtPath:fileSub];
}
}
return num / (1024.0 * 1024.0);
}
//计算单个文件大小
- (long long)fileSizeAtPath:(NSString *)file
{
NSFileManager *man = [NSFileManager defaultManager];
if ([man fileExistsAtPath:file]) {
return [[man attributesOfItemAtPath:file error:nil] fileSize];
}
return 0;
}

12 系统原生态二维码扫描（包括闪光灯，系统提示音）

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#import <AVFoundation/AVFoundation.h>
#import <AudioToolbox/AudioToolbox.h> // 系统提示音
#define SCANVIEW_EdgeTop 40.0
#define SCANVIEW_EdgeLeft 50.0
#define TINTCOLOR_ALPHA 0.2 //浅色透明度
#define DARKCOLOR_ALPHA 0.5 //深色透明度
#define VIEW_WIDTH [UIScreen mainScreen].bounds.size.width
#define VIEW_HEIGHT [UIScreen mainScreen].bounds.size.height
/*
＊＊＊＊＊＊＊＊＊注意：系统原生态二维码扫描苹果官方目前不支持扫扫描图册图片＊＊＊＊＊＊＊＊＊＊＊＊
1.第一步引入框架 AVFoundation.framework
2.第二步声明代理：AVCaptureMetadataOutputObjectsDelegate 。 define 几个东东用来画框、画线：
*/
@interface ViewController ()<AVCaptureMetadataOutputObjectsDelegate>
{
AVCaptureSession * session;//输入输出的中间桥梁
UIView *AVCapView;//此 view 用来放置扫描框、取消按钮、说明 label
UIView *_QrCodeline;//上下移动绿色的线条
NSTimer *_timer;
}
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
[self createUI];
// Do any additional setup after loading the view, typically from a nib.
}
#pragma mark 4.在某个方法中（我是点击扫描按钮）创建扫描界面，开始扫描
- (void)createUI{
//创建一个 view 来放置扫描区域、说明 label、取消按钮
UIView *tempView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, [UIScreen mainScreen].bounds.size.height )];
AVCapView = tempView;
AVCapView.backgroundColor = [UIColor colorWithRed:54.f/255 green:53.f/255 blue:58.f/255 alpha:1];
UIButton *cancelBtn = [[UIButton alloc]initWithFrame:CGRectMake(15, [UIScreen mainScreen].bounds.size.height - 100, 50, 25)];
UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(15, 268, 290, 60)];
label.numberOfLines = 0;
label.text = @"小提示：将条形码或二维码对准上方区域中心即可";
label.textColor = [UIColor grayColor];
[cancelBtn setTitle:@"取消" forState: UIControlStateNormal];
[cancelBtn setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];
[cancelBtn addTarget:self action:@selector(touchAVCancelBtn) forControlEvents:UIControlEventTouchUpInside];
[AVCapView addSubview:label];
[AVCapView addSubview:cancelBtn];
[self.view addSubview:AVCapView];
//画上边框
UIView *topView = [[UIView alloc] initWithFrame:CGRectMake(SCANVIEW_EdgeLeft, SCANVIEW_EdgeTop, VIEW_WIDTH- 22 * SCANVIEW_EdgeLeft, 1)];
topView.backgroundColor = [UIColor whiteColor];
[AVCapView addSubview:topView];
//画左边框
UIView *leftView = [[UIView alloc] initWithFrame:CGRectMake(SCANVIEW_EdgeLeft, SCANVIEW_EdgeTop , 1,VIEW_WIDTH - 22 * SCANVIEW_EdgeLeft )];
leftView.backgroundColor = [UIColor whiteColor];
[AVCapView addSubview:leftView];
//画右边框
UIView *rightView = [[UIView alloc] initWithFrame:CGRectMake(SCANVIEW_EdgeLeft + VIEW_WIDTH- 22 * SCANVIEW_EdgeLeft, SCANVIEW_EdgeTop , 1,VIEW_WIDTH - 22 * SCANVIEW_EdgeLeft + 1)];
rightView.backgroundColor = [UIColor whiteColor];
[AVCapView addSubview:rightView];
//画下边框
UIView *downView = [[UIView alloc] initWithFrame:CGRectMake(SCANVIEW_EdgeLeft, SCANVIEW_EdgeTop + VIEW_WIDTH- 22 * SCANVIEW_EdgeLeft,VIEW_WIDTH - 22 * SCANVIEW_EdgeLeft ,1 )];
downView.backgroundColor = [UIColor whiteColor];
[AVCapView addSubview:downView];
//闪光灯
UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
btn.frame = CGRectMake(150, [UIScreen mainScreen].bounds.size.height - 100, 80, 35);
[btn setTintColor:[UIColor grayColor]];
[btn setTitle:@"闪光灯" forState:UIControlStateNormal];
[btn addTarget:self action: @selector(OPEN:) forControlEvents:UIControlEventTouchUpInside];
[AVCapView addSubview:btn];
//画中间的基准线
_QrCodeline = [[UIView alloc] initWithFrame:CGRectMake(SCANVIEW_EdgeLeft + 1, SCANVIEW_EdgeTop, VIEW_WIDTH- 22 * SCANVIEW_EdgeLeft - 1, 2)];
_QrCodeline.backgroundColor = [UIColor greenColor];
[AVCapView addSubview:_QrCodeline];
// 先让基准线运动一次，避免定时器的时差
[UIView animateWithDuration:1.2 animations:^{
_QrCodeline.frame = CGRectMake(SCANVIEW_EdgeLeft + 1, VIEW_WIDTH - 22 * SCANVIEW_EdgeLeft + SCANVIEW_EdgeTop , VIEW_WIDTH - 22 * SCANVIEW_EdgeLeft - 1, 2);
}];
[self performSelector:@selector(createTimer) withObject:nil afterDelay:0.4];
AVCaptureDevice * device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
//创建输入流
AVCaptureDeviceInput * input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
//创建输出流
AVCaptureMetadataOutput * output = [[AVCaptureMetadataOutput alloc]init];
//设置代理在主线程里刷新
[output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
//初始化链接对象
session = [[AVCaptureSession alloc]init];
//高质量采集率
[session setSessionPreset:AVCaptureSessionPresetHigh];
[session addInput:input];
[session addOutput:output];
//设置扫码支持的编码格式(如下设置条形码和二维码兼容)
output.metadataObjectTypes=@[AVMetadataObjectTypeQRCode,AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode128Code];
AVCaptureVideoPreviewLayer * layer = [AVCaptureVideoPreviewLayer layerWithSession:session];
layer.videoGravity=AVLayerVideoGravityResizeAspectFill;
layer.frame = CGRectMake(SCANVIEW_EdgeLeft, SCANVIEW_EdgeTop, VIEW_WIDTH- 22 * SCANVIEW_EdgeLeft, 220);
[AVCapView.layer insertSublayer:layer atIndex:0];
//开始捕获
[session startRunning];
}
#pragma mark 调用闪光灯
- (void)OPEN:(UIButton *)btn{
btn.selected = !btn.isSelected;
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if ([device hasTorch]) {
[device lockForConfiguration:nil];
if (btn.selected) {
[device setTorchMode:AVCaptureTorchModeOn];
}else{
[device setTorchMode:AVCaptureTorchModeOff];
}
[device unlockForConfiguration];
}
}
- (void)touchAVCancelBtn{
//取消按钮的响应时间
}
#pragma mark 5.实现定时器、还有基准线的滚动方法
- (void)createTimer
{
_timer=[NSTimer scheduledTimerWithTimeInterval:1.1 target:self selector:@selector(moveUpAndDownLine) userInfo:nil repeats:YES];
}
- (void)stopTimer
{
if ([_timer isValid] == YES) {
[_timer invalidate];
_timer = nil;
}
}
// 滚来滚去 :D :D :D
- (void)moveUpAndDownLine
{
CGFloat YY = _QrCodeline.frame.origin.y;
if (YY != VIEW_WIDTH - 22 * SCANVIEW_EdgeLeft + SCANVIEW_EdgeTop ) {
[UIView animateWithDuration:1.2 animations:^{
_QrCodeline.frame = CGRectMake(SCANVIEW_EdgeLeft + 1, VIEW_WIDTH - 22 * SCANVIEW_EdgeLeft + SCANVIEW_EdgeTop , VIEW_WIDTH - 22 * SCANVIEW_EdgeLeft - 1,2);
}];
}else {
[UIView animateWithDuration:1.2 animations:^{
_QrCodeline.frame = CGRectMake(SCANVIEW_EdgeLeft + 1, SCANVIEW_EdgeTop, VIEW_WIDTH - 22 * SCANVIEW_EdgeLeft - 1,2);
}];
}
}
#pragma mark 6.扫描成功后，想干嘛干嘛，就在这个代理方法里面实现就行了
-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection{
if (metadataObjects.count>0) {
//[session stopRunning];
AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects objectAtIndex : 0 ];
//输出扫描字符串
NSLog(@"%@",metadataObject.stringValue);
AudioServicesPlaySystemSound(1307);
[session stopRunning];
[self stopTimer];
//[AVCapView removeFromSuperview];
}
}

13.webView计算高度

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1. //第一种：
3. - (void)webViewDidFinishLoad:(UIWebView *)webView{
5. float height = [[webView stringByEvaluatingJavaScriptFromString:@document.body.offsetHeight;] floatValue];
7. //document.body.scrollHeight
9. }
13. //第二种：
17. - (void) webViewDidFinishLoad:(UIWebView *)webView
19. {
21. CGRect frame = webView.frame;
23. CGSize fittingSize = [webView sizeThatFits:CGSizeZero];
25. frame.size = fittingSize;
27. webView.frame = frame;
29. }
33. //另外一种
35. - (void)viewDidLoad {
37. [super viewDidLoad];
39. webview.delegate = self;
41. [webview loadHTMLString:@
43. fdasfda
45. baseURL:nil];
47. }
49. - (void)webViewDidFinishLoad:(UIWebView *)webView
51. {
53. NSString *output = [webview stringByEvaluatingJavaScriptFromString:@document.getElementByIdx_x_x_x(foo).offsetHeight;];
55. NSLog(@height: %@, output);
57. }