1、页面跳转
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//隐藏底部的菜单栏
self.hidesBottomBarWhenPushed = YES;
// 初始化页面并且跳转
Newpage*newpage=[[Newpage alloc]init];
[self.navigationController pushViewController:about animated:YES];
//记得返回的时候显示底部菜单栏
self.hidesBottomBarWhenPushed = NO;
[newpage release];
about=nil;
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2、网络请求
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NSString *urlstring=@"www.baidu.com";
NSError *error =nil;//定义一个error类型的变量存储错误
//获取路径对象
NSArray *paths =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
//获取完整路径
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filename = [documentsDirectory stringByAppendingPathComponent:@"zhibin.plist"];
NSFileManager *fm=[NSFileManager defaultManager];//文件管理
//判断文件是否存在，如果存在则删除再重建，不存在 就创建
if ([fm fileExistsAtPath:filename]) {
if(reload){
//如果文件存在且是应用开启的第一次加载则删除上次的缓存 再重新创建
[fm removeItemAtPath:filename error:&error];
[fm createFileAtPath:filename contents:nil attributes:nil];}
reload=false;
} else {
//如果应用是安装完后第一次打开 则直接创建
[fm createFileAtPath:filename contents:nil attributes:nil];
}
//定义一个url类型的变量 然后把string类型的变量用urlwithstring函数转换为url
NSURL *url=[NSURL URLWithString:urlstring];
//定义一个request请求
NSURLRequest *request=[NSURLRequest requestWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10.0f];
//定义一个data类型来存储request类型的数据
NSData *respone=[NSURLConnection sendSynchronousRequest:request returningResponse:nil error:&error];
//定义一个string类型的把data类型枪支转换成字符类型并用utf8去转码
NSString *str=[[NSString alloc]initWithData:respone encoding:NSUTF8StringEncoding];
//字符串替换
str = [str stringByReplacingOccurrencesOfString:@"1" withString:@"2"];
NSData *res = [str dataUsingEncoding:NSUTF8StringEncoding];
if (res!=nil)//证明有返回数据
{
//定义一个字典类型的变量把data类型枪支转成字典类型
NSDictionary *jsonObject = [NSJSONSerialization JSONObjectWithData:res options:NSJSONReadingMutableLeaves error:&error];
//定义一个数组把查找字典中的根 把根的子孩子写入数组
NSMutableArray *templist = [jsonObject objectForKey:@"root"];
}
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3、显示本地图片
UIImage *image = [UIImage imageNamed:@"zhibin.png"];
[tmpImageArray addObject:image];
4、显示网络图片
// 指定URL生成UIImage
NSData *dt = [NSData dataWithContentsOfURL:
[NSURL URLWithString:@"http://xxx/aa.png"]];
UIImage *image = [[UIImage alloc] initWithData:dt];
5、全局变量
appdelegate.h
@property BOOL netstatus;
.m文件
AppDelegate *app=(AppDelegate *)[[UIApplication sharedApplication]delegate];
app.netstatus=YES;/
6、用户退出也可以保存的数据
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//添加一个退出也可以保存的用户变量
NSUserDefaults *set=[NSUserDefaults standardUserDefaults];
BOOL first=[set boolForKey:@"first"];
if(!first)
{
[set setBool:YES forKey:@"first"];
[set setInteger:1forKey:@"one"];
[set setBool:NO forKey:@"bool"];
[set setInteger:3 forKey:@"three"];
[set setInteger:4 forKey:@"four"];
[set setBool:YES forKey:@"five"];
}
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NSUserDefaults *set=[NSUserDefaults standardUserDefaults];
BOOL temp=[set boolForKey:@"five"];
6、allertview
UIAlertView *myalert = [[UIAlertView alloc] initWithTitle:@"警告" message:@"网络不存在" delegate:self cancelButtonTitle:@"确认"
otherButtonTitles:nil,nil];
[myalert show];
[myalert release];
7、图片下载到本地
.h文件
-(UIImage *)getImageFromURL:(NSString *)fileURL;
-(void)saveImage:(UIImage *)tupian withFileName:(NSString *)imageName ofType:(NSString *)extension inDirectory:(NSString *)directoryPath;
-(UIImage *)loadImage:(NSString *)fileName ofType:(NSString *)extension inDirectory:(NSString *)directoryPath;
.m文件
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UIImage *imageFromURL=[self getImageFromURL:picurl];
NSString *imagename=[xinwenid stringByAppendingFormat:@"_list"];
[self saveImage:imageFromURL withFileName:imagename ofType:@"jpg" inDirectory:documentsDiretoryPath];
UIImage *imageformweb=[self loadImage:imagename ofType:@"jpg" inDirectory:documentsDiretoryPath];
[tmpImageArray addObject:imageformweb];
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//下载图片
-(UIImage *)getImageFromURL:(NSString *)fileURL
{
UIImage *result;
NSData *data=[NSData dataWithContentsOfURL:[NSURL URLWithString:fileURL]];
result=[UIImage imageWithData:data];
return result;
}
//保存图片
-(void)saveImage:(UIImage *)tupian withFileName:(NSString *)imageName ofType:(NSString *)extension inDirectory:(NSString *)directoryPath{
if ([[extension lowercaseString]isEqualToString:@"png"]) {
[UIImagePNGRepresentation(tupian) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@",imageName,@"png"]] options:NSAtomicWrite error:nil];
}else if ([[extension lowercaseString]isEqualToString:@"jpg"]||[[extension lowercaseString]isEqualToString:@"jpeg"] )
{
[UIImageJPEGRepresentation(tupian, 1.0) writeToFile:[directoryPath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.%@",imageName,@"jpg"]] options:NSAtomicWrite error:nil];
}else
{
NSLog(@"不认识拓展名");
}
}
//加载图片
-(UIImage *)loadImage:(NSString *)fileName ofType:(NSString *)extension inDirectory:(NSString *)directoryPath
{
UIImage *result=[UIImage imageWithContentsOfFile:[NSString stringWithFormat:@"%@/%@.%@",directoryPath,fileName,extension]];
return result;
}
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8、页面左右滑动
UISwipeGestureRecognizer *recognizer;
recognizer=[[UISwipeGestureRecognizer alloc]initWithTarget:self action:@selector(handleSwipeFrom5:)];
[recognizer setDirection:(UISwipeGestureRecognizerDirectionRight)];
[self.view addGestureRecognizer:recognizer];
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-(void)handleSwipeFrom5:(UISwipeGestureRecognizer*)recognizer
{
if(recognizer.direction==UISwipeGestureRecognizerDirectionRight)
{
self.hidesBottomBarWhenPushed = YES;
[self.navigationController popViewControllerAnimated:YES];
// self.tabBarController.selectedIndex=0;
// self.hidesBottomBarWhenPushed = NO;
}
}
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9、 .m文件里面创建控件
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UILabel *introduce = [[UILabel alloc] initWithFrame:CGRectMake(15, 230, 290, 160)];
[introduce setFont:[UIFont fontWithName:@"Helvetica" size:17]];
[introduce setTextColor:[UIColor grayColor]];
[introduce setNumberOfLines:0];
[introduce setBackgroundColor:[UIColor clearColor]];
introduce.lineBreakMode = UILineBreakModeWordWrap;
introduce.text = @" 1111\n\n 222\n\n 333\n\n 4444";
[self.view addSubview:introduce];
UIImageView *logoimg1 = [[UIImageView alloc] initWithFrame:CGRectMake(55, 15, 200, 200)];
[logoimg1 setImage:[UIImage imageNamed:@"aboutlogo.png"]];
[self.view addSubview:logoimg1];
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10、数组
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NSMutableArray *items=[[NSMutableArray alloc]init];
[items addObject:@"1"];
[items addObject:@"2"];
[items insertObject:@"0" atIndex:0];
int i=[items count];
[items addObject:[NSNull null]];
for (int i=0; i<items.count; i++) {
NSLog(@"%@",[items objectAtIndex:i]);
}
[items release];
items=nil;
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11、判断字符串长度
NSString *nsstring=@"hello world";
int len=[nsstring length];
int len=[@"hello world" length];
nsstring=[[NSString alloc]initWithString:@"hello world"];
int len=[nsstring length];