iOS 开发小技巧（一）
liuwentao 2013-04-08
1.取字符串中的某段字符串
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NSString*str=@"12sadfsdf56afsdf";
NSLog(@"%@",str);
NSString*thrStr=[strstringByReplacingOccurrencesOfString:@"56"withString:@"88"];
NSLog(@"%@",thrStr);
即把12sadfsdf56afsdf中的56替换为88，替换后字符串为：12sadfsdf88afsdf
2.简单plist获取
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NSString*path=[[NSBundlemainBundle]pathForResource:@"Array"ofType:@"plist"];
NSMutableDictionary*data=[[NSMutableDictionaryalloc]initWithContentsOfFile:path];
NSLog(@"%d",[datacount]);
NSLog(@"%@",[dataallValues]);
NSLog(@"------------");
NSArray*ary=[dataallKeys];
NSLog(@"%d",[arycount]);
NSArray*array=[NSArrayarrayWithArray:ary];
for(inti=0;i<[arraycount];i++)
{
NSLog(@"\nvalue=%@",[arrayobjectAtIndex:i]);
}
NSArray*getArray=[[dataallValues]objectAtIndex:5];
NSLog(@"get_array:%@",getArray);
3.状态栏和UINavigationBar设置成透明
[[UIApplicationsharedApplication]setStatusBarStyle:UIStatusBarStyleBlackTranslucent];//状态栏设置为透明
theNavigationController.navigationBar.barStyle=UIBarStyleBlackTranslucent;//设置navigationBar为透明
4.设置object圆角，如UIView、UIImageView等
简单几步：
一.导入QuartzCore.framework框架#import<QuartzCore/QuartzCore.h>
二.object.layer.masksToBounds=YES;
三.object.layer.cornerRadius=XXX;
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UIImageView*testImageView=[[UIImageViewalloc]initWithImage:[UIImageimageNamed:@"1.jpg"]];
[testImageViewsetFrame:CGRectMake(20,20,100,100)];
testImageView.layer.masksToBounds=YES;
testImageView.layer.cornerRadius=50/2;//设置的角度，改变查看效果
testImageView.layer.borderWidth=5;//边框宽度
testImageView.layer.borderColor=[UIColoryellowColor].CGColor;//边框颜色
[self.viewaddSubview:testImageView];
[testImageViewrelease];
5.程序是启动状态时设置屏幕一直亮
UIApplication*appDelegate=[UIApplicationsharedApplication];
appDelegate.idleTimerDisabled=YES;
6.设置UITableViewCell显示子标题
初始化时：cell=[[UITableViewCellalloc]initWithStyle:UITableViewCellStyleSubtitlereuseIdentifier:CellIdentifier];
此处样式应注意，即设置为显示子标题样式，默认样式为不显示子标题，设置完后可用：
cell.detailTextLabel.text=@"详细标签";设置子标题
7.给UIView设置阴影效果
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UIView*showView=[[UIViewalloc]initWithFrame:CGRectMake(10,150,100,100)];
showView.backgroundColor=[UIColorredColor];
showView.layer.shadowOffset=CGSizeMake(15,5);
showView.layer.shadowOpacity=0.6;
showView.layer.shadowColor=[UIColorblackColor].CGColor;
[self.viewaddSubview:showView];
[showViewrelease];
8.设置UITableView选中行数的位置
[self.tableViewselectRowAtIndexPath:[NSIndexPathindexPathForRow:5inSection:0]animated:NOscrollPosition:UITableViewScrollPositionMiddle];
//selectRowAtIndexPath设置行数和sectionscrollPosition设置滚动到的位置（4项可供选择）
9.UITextField每次操作调用的代理，可根据需求作相应改变
-(BOOL)textField:(UITextField*)textFieldshouldChangeCharactersInRange:(NSRange)rangereplacementString:(NSString*)string
{
NSMutableString*newString=[[textField.textmutableCopy]autorelease];
[newStringreplaceCharactersInRange:rangewithString:string];//得到改变的字符串
}
10.如何用UIColor生成UIImage
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-(void)viewDidLoad
{
[superviewDidLoad];
UIImageView*imageView=[[UIImageViewalloc]initWithFrame:CGRectMake(10,10,100,100)];
UIImage*image=[selfcreateImageWithColor:[UIColoryellowColor]];//生成一张黄颜色的图片
[imageViewsetImage:image];
[self.viewaddSubview:imageView];
[imageViewrelease];
}
-(UIImage*)createImageWithColor:(UIColor*)color
{
CGRectrect=CGRectMake(0.0f,0.0f,1.0f,1.0f);
UIGraphicsBeginImageContext(rect.size);
CGContextRefcontext=UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context,[colorCGColor]);
CGContextFillRect(context,rect);
UIImage*theImage=UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
returntheImage;
}
