iPhone开发技巧

来源：互联网发布：iso8859 java 编辑：程序博客网时间：2024/06/04 17:39

原文地址。

1、如果在程序中想对某张图片进行处理的话（得到某张图片的一部分）可一用以下代码：

UIImage *image = [UIImage imageNamed:filename];

CGImageRef imageRef = image.CGImage;

CGRect rect = CGRectMake(origin.x, origin.y ,size.width, size.height);

CGImageRef imageRefRect = CGImageCreateWithImageInRect(imageRef, rect);

UIImage *imageRect = [[UIImage alloc] initWithCGImage:imageRefRect];

===================学习补充个

截取给定View返回image （当前看到的视图的image）

- (UIImage *)captureWithView:(UIView *) view
{
if(version7)
{
UIGraphicsBeginImageContext(view.frame.size);
}
else
{
UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.opaque,0.0);

//在ios7中不执行不会报错但是界面就卡在那边找了很久才找到问题的根源这个方法截取的图片会比上一个清晰但是IOS7中不能执行了只能用上面一个方法
}
[view.layerrenderInContext:UIGraphicsGetCurrentContext()];
UIImage * img =UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}

2、判断设备是iphone还是iphone4的代码：

640*960 3.5寸为iPhone4

#define isRetina ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640, 960), [[UIScreen mainScreen] currentMode].size) : NO)

640*960 4寸为iPhone5

//判断是否为4寸设备设备

#define inch4 ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640,1136), [[UIScreen mainScreen] currentMode].size) : NO)

版本号判断

//是否为7.0以上的的设备

#define version7 ([[[UIDevice currentDevice] systemVersion] floatValue] >=7.0 ? YES:NO)

3、判断邮箱输入的是否正确：

- (BOOL) validateEmail: (NSString *) candidate

{

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:candidate];

}

强大的NSPredicete 大家可以看看这个

http://blog.sina.com.cn/s/blog_859ab336010158dz.html

4、如何把当前的视图作为照片保存到相册中去：

#import <QuartzCore/QuartzCore.h>

UIGraphicsBeginImageContext(currentView.bounds.size); //currentView 当前的view

[currentView.layer renderInContext:UIGraphicsGetCurrentContext()];

UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);

= = 上面自己添加了.....

5、本地通知（类似于push通知）按home键到后台十秒后触发：

UILocalNotification *notification=[[UILocalNotification alloc] init];

if (notification!=nil) {

NSLog(@">> support local notification");

NSDate *now=[NSDate new];

notification.fireDate=[now addTimeInterval:10];

notification.timeZone=[NSTimeZone defaultTimeZone];

notification.alertBody=@"该去吃晚饭了！";

[[UIApplication sharedApplication].scheduleLocalNotification:notification];

}

又是个不懂的东西

电脑编译有问题有些函数已经弃用了

UILocalNotification *notification=[[UILocalNotificationalloc]init];

if (notification!=nil)

{

NSDate *now=[NSDatedate];

notification.fireDate=[now dateByAddingTimeInterval:5]; //5秒后推送

notification.timeZone=[NSTimeZonedefaultTimeZone];

notification.repeatInterval = kCFCalendarUnitWeek;

notification.alertBody=@"该去吃晚饭了！";

notification.alertAction = @"打开";

// notification.hasAction = YES;

notification.applicationIconBadgeNumber =1; //应用上的红色提示数字 application.applicationIconBadgeNumber = 0;原来那个数字提示是这样改的

notification.soundName =UILocalNotificationDefaultSoundName;

[[UIApplicationsharedApplication]scheduleLocalNotification:notification];

}

改过之后的效果

参考： http://www.cnblogs.com/bandy/archive/2012/03/29/2423555.html

6、捕获iphone通话事件：

CTCallCenter *center = [[CTCallCenter alloc] init];

center.callEventHandler = ^(CTCall *call) //有个块的用法

{

NSLog(@"call:%@", call.callState);

}

7、iOS 4 引入了多任务支持，所以用户按下 “Home” 键以后程序可能并没有退出而是转入了后台运行。如果您想让应用直接退出，最简单的方法是：在 info－plist 里面找到 Application does not run in background 一项，勾选即可。

8、使UIimageView的图像旋转：

float rotateAngle = M_PI;

CGAffineTransform transform =CGAffineTransformMakeRotation(rotateAngle);

imageView.transform = transform;

9、设置旋转的原点：

#import <QuartzCore/QuartzCore.h>

UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"bg.png"]];

imageView.layer.anchorPoint = CGPointMake(0.5, 1.0);

++++++++++ 更改图片的锚点

self.imageV.frame = cgrectmake(-160,150,320,160);

self.imageV.layer.anchorPoint =CGPointMake(0,0.5);

//设置锚点的时候旋转的中心点没有变是改变了图片的位置默认锚点为（0.5，0.5）

//让图片在屏幕的左边旋转以前不懂将图片加在两倍imageV宽的View 中选中view达到那种效果现在设置锚点就可以了个人理解一张图片大小位置确定后图片的旋转的中心点就确定了这时改变锚点是该片图片的layer相对这个锚点的位置

frame.origin.x = center.x - anchorPoint.x * bounds.size.width/2.0;//上面的imageV的layer的_x变为0
frame.origin.y = center.y - anchorPoint.x * bounds.size.height/2.0;//上面的imageV的layer的_y没有变
frame.size = bounds.size;大小不变

可以看看这个：http://blog.csdn.net/ch_soft/article/details/8199251

可以试试让他转转....

10、实现自定义的状态栏（遮盖状态栏）：

CGRect frame = {{0, 0}, {320, 20}};//好吧 frame还可以这样写学习了笨啊

UIWindow* wd = [[UIWindow alloc] initWithFrame:frame];

[wd setBackgroundColor:[UIColor clearColor]];

[wd setWindowLevel:UIWindowLevelStatusBar];

frame = CGRectMake(100, 0, 30, 20);

UIImageView* img = [[UIImageView alloc] initWithFrame:frame];

[img setContentMode:UIViewContentModeCenter];

[img setImage:[UIImage imageNamed:@"00_0103.png"]];

[wd addSubview:img];

[wd makeKeyAndVisible];

[UIView beginAnimations:nil context:nil];

[UIView setAnimationDuration:2];

frame.origin.x += 150;

[img setFrame:frame];

[UIView commitAnimations];

= =试验过上面那样写不可以找了好久终于找到问题的根源 UIWidow 要定义成变量或者属性不能是临时的不然不能显示

11、在程序中实现电话的拨打：

//添加电话图标按钮

UIButton *btnPhone = [[UIButton buttonWithType:UIButtonTypeCustom] retain];

btnPhone.frame = CGRectMake(280,10,30,30);

UIImage *image = [UIImage imageNamed:@"phone.png"];

[btnPhone setBackgroundImage:image forState:UIControlStateNormal];

//点击拨号按钮直接拨号

[btnPhone addTarget:self action:@selector(callAction:event:)forControlEvents:UIControlEventTouchUpInside];

[cell.contentView addSubview:btnPhone]; //cell是一个UITableViewCell

//定义点击拨号按钮时的操作

- (void)callAction:(id)sender event:(id)event{

NSSet *touches = [event allTouches];

UITouch *touch = [touches anyObject];

CGPoint currentTouchPosition = [touch locationInView:self.listTable];

NSIndexPath *indexPath = [self.listTable indexPathForRowAtPoint: currentTouchPosition];

if (indexPath == nil) {

return;

}

NSInteger section = [indexPath section];

NSUInteger row = [indexPath row];

NSDictionary *rowData = [datas objectAtIndex:row];

NSString *num = [[NSString alloc] initWithFormat:@"tel://%@",number]; //number为号码字符串

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:num]]; //拨号

}

= =说了一堆只有最后两句话有用疼建议大家看看这个： http://blog.sina.com.cn/s/blog_65a8ab5d01017nlg.html

NSString *number =@"号码可以填自己的号码实验";

NSString *num = [[NSString alloc] initWithFormat:@"tel://%@",number]; //number为号码字符串如果使用这个方法结束电话之后会进入联系人列表

NSString *num = [[NSStringalloc]initWithFormat:@"telprompt://%@",number];//而这个方法则打电话前先弹框是否打电话然后打完电话之后回到程序中网上说这个方法可能不合法无法通过审核

这里面有很多自己没做的和不知道的东西等下下面把工程文件传上来共享

12、更改iphone的键盘颜色：

1.只有这2种数字键盘才有效果。UIKeyboardTypeNumberPad，UIKeyboardTypePhonePad

2. keyboardAppearance ＝ UIKeyboardAppearanceAlert

- (void)textViewDidBeginEditing:(UITextView *)textView{

NSArray *ws = [[UIApplication sharedApplication] windows];

for(UIView *w in ws){

NSArray *vs = [w subviews];

for(UIView *v in vs)

{

if([[NSString stringWithUTF8String:object_getClassName(v)] isEqualToString:@"UIKeyboard"])

{

v.backgroundColor = [UIColor redColor];

}

= = 靠又折腾了很久这个颜色设置对uitextField无效而且关键字也不是UIKeyboard 大家不行的话用

UIPeripheralHostView 试试这个键盘设置在uitextview上才能设置

13、设置时区

NSTimeZone *defaultTimeZone = [NSTimeZone defaultTimeZone];

NSTimeZone *tzGMT = [NSTimeZone timeZoneWithName:@"GMT"];

[NSTimeZone setDefaultTimeZone:tzGMT];

上面两个时区任意用一个。

14、Ipad隐藏键盘的同时触发方法。

[[NSNotificationCenter defaultCenter] addObserver:self

selector:@selector(keyboardWillHide:)

name:UIKeyboardWillHideNotification

object:nil];

- (IBAction)keyboardWillHide:(NSNotification *)note//键盘的监听方法

14、在一个程序中打开另一个程序的方法。

http://www.cocoachina.com/iphonedev/sdk/2010/0322/768.html

15、计算字符串的字数

-(int)calculateTextNumber:(NSString *)text

{

float number = 0.0;

int index = 0;

for (index; index < [text length]; index++)

{

NSString *protoText = [text substringToIndex:[text length] - index];

NSString *toChangetext = [text substringToIndex:[text length] -1 -index];

NSString *charater;

if ([toChangetext length]==0)

{

charater = protoText;

}

else

{

NSRange range = [text rangeOfString:toChangetext];

charater = [protoText stringByReplacingCharactersInRange:range withString:@""];

}

NSLog(charater);

if ([charater lengthOfBytesUsingEncoding:NSUTF8StringEncoding] == 3)

{

number++;

}

else

{

number = number+0.5;

}

return ceil(number);

}

练习的工程文件下载地址戳这里..........