#import "AppDelegate.h"
#import "RootController.h"
#import "NewTableViewController.h"@interface AppDelegate ()@end@implementation AppDelegate-(void)dealloc{[self.window release];[super dealloc];
}- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];// Override point for customization after application launch.self.window.backgroundColor = [UIColor whiteColor];[self.window makeKeyAndVisible];/* */RootController * RootVC = [[RootController alloc]init];UINavigationController * navl = [[UINavigationController alloc]initWithRootViewController:RootVC];self.window.rootViewController = navl;[RootVC release];[navl release];/*//使用 uitableViewcontrollerNewTableViewController * RootVC = [[NewTableViewController alloc]init];UINavigationController * navl = [[UINavigationController alloc]initWithRootViewController:RootVC];self.window.rootViewController = navl;[RootVC release];[navl release];*/return YES;
}

#import <UIKit/UIKit.h>
#import "Contacts.h"
#import "UIImage+Scale.h"
#import "CustomCell.h"@interface RootController : UIViewController@end

//
//  RootController.m

#import "RootController.h"
#import "DetailViewController.h"@interface RootController ()<UITableViewDataSource,UITableViewDelegate>
@property(nonatomic,retain)NSMutableDictionary * dataDic;//存储所有联系人
@property(nonatomic,retain)NSMutableArray * sortedKeys;//存储排好序的 key
@property(nonatomic,retain)Contacts * per1;
@end
/*一个工程的基本框架的规范组成Appdelegate //这里存放一些工程的代理事件Resource // 存放工程的公共资源 图片 音频General // 存放共有的类，可以重复使用的共有的类Macro // 存放一些宏定义Vender //存放第三方类Section {模块一{ Controller Model  View }模块二{ Controller Model  View }模块三{ Controller Model  View }...}
*/
@implementation RootController
/*tableView 的编辑1.添加编辑按钮2.重写 setEditing:(BOOL)editing animated:(BOOL)animated 方法3.设置 tableView 的可编辑状态4.设置 tableView 的编辑样式 也可以设置哪些行可以被编辑 （Delegate）5.提交编辑状态 对数据以及界面进行处理 （真正的数据是放在集合或或数组，者字典里）*/- (void)viewDidLoad {[super viewDidLoad];UITableView * tableView =[[UITableView alloc]initWithFrame:[[UIScreen mainScreen]bounds] style:UITableViewStylePlain];tableView.separatorColor = [UIColor grayColor];tableView.dataSource = self;//设置数据源tableView.delegate = self;//设置代理tableView.separatorInset = UIEdgeInsetsMake(0, 10, 0, 10);self.view = tableView;//设置 tableView 为根视图
    [tableView release];[self coustomNavBar];//添加系统自带的编辑按钮//从本地读取数据
    [self readDAtaFromLocal];
}
#pragma mark ---------读取本地数据
-(void)readDAtaFromLocal{NSString  * filePath = [[NSBundle mainBundle]pathForResource:@"contacts" ofType:@"plist"];self.dataDic = [NSMutableDictionary dictionaryWithContentsOfFile:filePath];NSDictionary * dic = [NSMutableDictionary dictionaryWithDictionary:self.dataDic];//拷贝出来一份给不可变字典  对不可变字典遍历NSDictionary * dict = [NSDictionary dictionaryWithDictionary:dic];//获取拍好序的 keyNSArray * sorted = [[dict allKeys]sortedArrayUsingSelector:@selector(compare:)];self.sortedKeys = [NSMutableArray arrayWithArray:sorted];//不能一边遍历结合一边操作//外层字典遍历
//    for (NSString * key in dict) { 得到的是无序的for (NSString * key in _sortedKeys) {NSMutableArray * contactArr = [NSMutableArray array];NSArray * group = [dict objectForKey:key];//内层遍历获取每一个分组 将 dic 的信息封装到 Contacts 对象里面for (NSDictionary * dic in group) {Contacts *per = [[Contacts alloc]initWithDic:dic];//将联系人村放到数组中
            [contactArr addObject: per];}//重新把原来的大字典赋拍好序的信息
        [self.dataDic setValue:contactArr forKey:key];}
}
#pragma mark0 --------必须实现的两个方法
//设置分区的行数
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
//    return [self.dataDic[_sortedKeys[section]] count];//不同的section就是不同的key，代表了不同的组， section的值即为key排好序后的 数组的下标NSArray *everyKeyForGroup = [self.dataDic valueForKey: self.sortedKeys[section]];return everyKeyForGroup.count;
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{static NSString * identifier = @"cell";CustomCell * cell = [tableView dequeueReusableCellWithIdentifier:identifier];//如果没有获取成功，就新建 cellif (!cell) {cell = [[[CustomCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:identifier]autorelease];}//获取分组的 keyNSString * key =  [_sortedKeys objectAtIndex:indexPath.section];//获取对应的分组NSArray * group = [self.dataDic objectForKey:key];//获取联系人对象Contacts * contact = [group objectAtIndex:indexPath.row];//为 cell 赋新值self.per1 = contact;cell.nameLabel.text = contact.name;cell.contentLabel.text =contact.phoneNum;cell.photoView.image = [[UIImage imageNamed:contact.photo]scaleToSize:CGSizeMake(50, 50)];//使用到了图片的方法的分类
    [cell.callBtn addTarget:self action:@selector(handleCallBtn:) forControlEvents:UIControlEventTouchUpInside];//点击呼叫return cell;
}
//打电话就条状下一页(这里的功能还没有实现？？？？？？？？？？？？？)
-(void)handleCallBtn:(UIButton *)sender{DetailViewController * detalVC = [[DetailViewController alloc]init];detalVC.name = self.per1.name;detalVC.phonenum = self.per1.phoneNum;detalVC.image = [UIImage imageNamed:self.per1.photo];[self.navigationController pushViewController:detalVC animated:YES];[detalVC release];
}
-(void)viewWillDisappear:(BOOL)animated{}
//设置分区数
-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{return _sortedKeys.count;
}
//设置分区标题
-(NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section{return self.sortedKeys[section];
}
//指定行高
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{return 60;
}
- (void)didReceiveMemoryWarning {[super didReceiveMemoryWarning];// Dispose of any resources that can be recreated.
}
#pragma mark1 ------------添加系统自带的编辑按钮
-(void)coustomNavBar{//添加系统自带的编辑按钮 （done 不可编辑 edit 可以编辑）self.navigationItem.rightBarButtonItem = self.editButtonItem;
}
#pragma mark2 ------------ 重写 setEditing:(BOOL)editing animated:(BOOL)animated 方法
//重写方法
-(void)setEditing:(BOOL)editing animated:(BOOL)animated{[super setEditing:editing animated:animated];//editing Edit：YES 可编辑的   Done : NO 不可编辑//设置 tableview 的编辑状态 目的就是让 tableView 处于编辑状态[(UITableView *)self.view setEditing:editing animated:YES];
}
#pragma mark3 -----------提交编辑状态 对数据以及界面进行处理 （真正的数据是放在集合或或数组，者字典里）
//设置哪些行可以被编辑
-(BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath{if (indexPath.row == 1) {//某行能否被修改return YES;}return YES;
}#pragma mark4 ------------设置 tableView 的编辑样式
- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath{if (indexPath.section == 0) {//设置第一分组可以添加 一些数据return UITableViewCellEditingStyleInsert;//插入样式
    }return UITableViewCellEditingStyleDelete;//删除样式
}
- (NSString *)tableView:(UITableView *)tableView titleForDeleteConfirmationButtonForRowAtIndexPath:(NSIndexPath *)indexPath NS_AVAILABLE_IOS(3_0){return @"点我删除";
}//提交编辑状态 提交编辑状态的时刻 被触发
-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath{//获取到编辑的这一行所在的位置 （key）NSString * key  = [self.sortedKeys objectAtIndex:indexPath.section];//获取到联系人的数组NSMutableArray * group = [_dataDic objectForKey:key];//获取到对应的联系人对象Contacts * contact = [group objectAtIndex:indexPath.row];
//    Contacts * contact = group[indexPath.row];//也可这样写//判断编辑状态if (editingStyle == UITableViewCellEditingStyleDelete) {
//        if (indexPath.row == 2) {//0
//            [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
//        }//删除操作//需要判断是否需要删除对应的分区,当数组的联系人只有一个的时候，这时候需要把该联系人对应的分区也要被删除if (group.count == 1) {//删除整个分区//1.数据源删除 删除对应分组的信息[_dataDic removeObjectForKey:key];//删除对应的分组的数据[_sortedKeys removeObject:key];//删除对应的 key//2.界面上删除 修改界面  删除所在分区的界面
            [tableView deleteSections:[NSIndexSet indexSetWithIndex:indexPath.section] withRowAnimation:UITableViewRowAnimationBottom];}else{//删除该行//1.数据源[group removeObject:contact];//删除联系人//2.界面
#warning  mark @[indexPath]   什么意思？[tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationLeft];}}//添加编辑状态else{//添加操作//1.数据源操作NSDictionary * dic = @{@"name":@"白白",@"gender":@"男",@"phoneNum":@"12345625602",@"photo":@"uuuuuu"};//将字典封装成联系人对象Contacts * newPer = [[Contacts alloc]initWithDic:dic];//将联系人添加到对应的分区的联系人数组里[group insertObject:newPer atIndex:indexPath.row];//添加一个联系人//2.界面操作[tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationRight];//界面上添加一个联系人
        [newPer release];}
}// PM
#pragma mark5 ------------设置 tableView 的cell 的移动
//移动（设置某些行的 cell 可以移动）(先打一个 BOOl 寻找方法)
-(BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath{return YES;
}
//提交移动的操作 （先打 void 再寻找方法）
-(void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath{//该方法 sourceIndexPath 是原来的区域 destinationIndexPath 是移动后的区域//做移动操作的时候，界面上已经发生了改变.所以我们只需要处理数据上的//获取分组的数组//获取外层大字典的 keyNSString * key = [self.sortedKeys objectAtIndex:sourceIndexPath.section];NSMutableArray * group =  [_dataDic objectForKey:key];//这里写 retain 的原因就是让其引用计数器加1，保持所有权Contacts * per = [[group objectAtIndex:sourceIndexPath.row]retain];//让引用计数加1，保证对象的存在//从数组中把对应的 per 对象从数组中删除
    [group removeObjectAtIndex:sourceIndexPath.row];//然后再把对应的对象移动到目的位置
    [group insertObject:per atIndex:destinationIndexPath.row];[per release];
}
//限定 cell 的移动界限 ----禁止跨区移动
-(NSIndexPath *)tableView:(UITableView *)tableView targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath{//tableView  当前操作的 tableview//sourceIndexPath 移动之前的下标索引值 就是移动之前的 cell 的位置//proposedDestinationIndexPath 移动之后所得到的目的位置//如果移动之前 和 移动之后的所在分区是同一个分区，则支持移动if ( sourceIndexPath.section == proposedDestinationIndexPath.section) {return proposedDestinationIndexPath;//移动的位置}else{return sourceIndexPath;//原来位置
    }}
@end

#import <UIKit/UIKit.h>@interface NewTableViewController : UITableViewController@end

//
//  NewTableViewController.m

#import "NewTableViewController.h"@interface NewTableViewController ()@end@implementation NewTableViewController
/*UITableViewController 和 UIViewController 的区别1.前者的根视图是 tableView  后者是 UIView2.如果用 UIView 的话 需要再设置 dataSource ，前者不用再设置 dataSource 和 delegate ,同时也不用再服从协议，因为自身已经服从了， 而后者我们需要指定他的 dataSource 和 delegate3.前者不用重写 setEdting:Animation : 方法控制 tabelview，后者需要指定4.前者已经自动的帮我们生成了对应的 dataSource 的最基本最常用的协议的方法（需要使用，就注开就可以了），后者需要自己去手动添加相应的协议方法*/
- (void)viewDidLoad {[super viewDidLoad];//     Uncomment the following line to preserve selection between presentations.
//     self.clearsSelectionOnViewWillAppear = NO;//     Uncomment the following line to display an Edit button in the navigation bar for this view controller.self.navigationItem.rightBarButtonItem = self.editButtonItem;
}- (void)didReceiveMemoryWarning {[super didReceiveMemoryWarning];if ([self isViewLoaded] && !self.view.window) {self.view = nil;}
}#pragma mark - Table view data source- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
#warning Potentially incomplete method implementation.// Return the number of sections.return 4;
}- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
#warning Incomplete method implementation.// Return the number of rows in the section.return 2;
}/*UIActionSheetUIAlertView调用系统的相册，查询相册UIDatePickerUIPickerView绘图 DrawRectUITextViewUIToolBar*/- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {//设置重用标志符static NSString * identifier = @"cell";//根据重用的标志符在 重用列表中取 cellUITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];//如果没有获取重用的 cell ,则新建if (!cell) {cell = [[[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier]autorelease];}// Configure the cell...cell.textLabel.text = @"时间广场";return cell;
}/**/
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {// Return NO if you do not want the specified item to be editable.return YES;
}/*
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {if (editingStyle == UITableViewCellEditingStyleDelete) {// Delete the row from the data source[tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];} else if (editingStyle == UITableViewCellEditingStyleInsert) {// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view}
}
*//*
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath {
}
*//*
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath {// Return NO if you do not want the item to be re-orderable.return YES;
}
*//*
#pragma mark - Navigation// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {// Get the new view controller using [segue destinationViewController].// Pass the selected object to the new view controller.
}
*/@end

#import <Foundation/Foundation.h>@interface Contacts : NSObject@property(nonatomic,copy)NSString * name;
@property(nonatomic,copy)NSString * gender;
@property(nonatomic,copy)NSString * phoneNum;
@property(nonatomic,copy)NSString * photo;-(id)initWithDic:(NSDictionary *)dic;@end

#import "Contacts.h"@implementation Contacts-(id)initWithDic:(NSDictionary *)dic{self  = [super init];if (self) {[self setValuesForKeysWithDictionary:dic];}return self;
}
- (void)setValue:(id)value forUndefinedKey:(NSString *)key {NSLog(@"key值不存在(⊙o⊙)哦");
}@end

#import <UIKit/UIKit.h>@interface CustomCell : UITableViewCell
@property (nonatomic , retain) UIImageView *photoView;
@property (nonatomic , retain) UILabel *nameLabel;
@property (nonatomic , retain) UILabel *contentLabel;
@property (nonatomic , retain) UIButton *callBtn;@end

//
//  CustomCell.m

#import "CustomCell.h"@implementation CustomCell-(instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier{self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];if (self) {[self customSubViews];//自定义 cell 控件
    }return self;
}-(void)customSubViews{//photoViewself.photoView = [[UIImageView alloc] initWithFrame:CGRectMake(15, 8, self.frame.size.width / 4 - 20, self.frame.size.height)];
//    _photoView.backgroundColor = [UIColor greenColor];
    [self.contentView addSubview:_photoView];_photoView.layer.cornerRadius = 20;_photoView.layer.masksToBounds = YES;//当绘制底层的边界的时候,本控件也和边界一起绘制
    [_photoView release];//nameLableself.nameLabel = [[UILabel alloc] initWithFrame:CGRectMake(self.frame.size.width / 4 , 12, self.frame.size.width / 3 - 20, self.frame.size.height -20)];_nameLabel.textAlignment = UITextAlignmentCenter;
//    _nameLabel.backgroundColor = [UIColor orangeColor];
    [self.contentView addSubview:_nameLabel];[_nameLabel release];//contenlableself.contentLabel = [[UILabel alloc] initWithFrame:CGRectMake(_nameLabel.frame.origin.x + self.frame.size.width / 3 - 20, 12, self.frame.size.width / 3 , self.frame.size.height -20)];
//    _contentLabel.backgroundColor = [UIColor greenColor];
    [self.contentView addSubview:_contentLabel];[_contentLabel release];//callBtnself.callBtn = [UIButton buttonWithType:UIButtonTypeRoundedRect];_callBtn.backgroundColor = [UIColor redColor];_callBtn.alpha = 0.4;_callBtn.frame = CGRectMake(_nameLabel.frame.origin.x + self.frame.size.width / 3 - 8 + self.frame.size.width / 3  + 5, 12, self.frame.size.width / 6 , self.frame.size.height -20);
//    [_callBtn addTarget:self action:@selector(handleCallBtn:) forControlEvents:UIControlEventTouchUpInside];[_callBtn setTitle:@"呼叫" forState:UIControlStateNormal];[self.contentView addSubview:_callBtn];
}@end

#import <UIKit/UIKit.h>@interface DetailViewController : UITableViewController
@property(nonatomic,retain)NSString * name;
@property(nonatomic,retain)NSString * phonenum;
@property(nonatomic,retain)UIImage * image;
@end

//
//  DetailViewController.m

#import "DetailViewController.h"@interface DetailViewController ()@end@implementation DetailViewController- (void)viewDidLoad {[super viewDidLoad];[self setUpDetail];[self commensetting];}-(void)commensetting{
//    self.navigationItem.title = @"XXX详细信息";
}
-(void)setUpDetail{UIView * backView = [[UIView alloc]initWithFrame:[[UIScreen mainScreen]bounds]];self.view  = backView;backView.backgroundColor = [UIColor orangeColor];UIImageView * imageView = [[UIImageView alloc]initWithFrame:CGRectMake(50, 100, 100, 100)];[imageView setImage:self.image];[self.view addSubview:imageView];imageView.backgroundColor = [UIColor blackColor];UILabel *lable1 = [[UILabel alloc]initWithFrame:CGRectMake(200, 100, 60, 30)];lable1.textAlignment = UITextAlignmentLeft;lable1.text = self.name;[self.view addSubview:lable1];[lable1 release];UILabel *lable2 = [[UILabel alloc]initWithFrame:CGRectMake(200, 150, 60, 30)];lable2.textAlignment = UITextAlignmentLeft;lable2.text = self.phonenum;[self.view addSubview:lable2];[lable2 release];
}- (void)didReceiveMemoryWarning {[super didReceiveMemoryWarning];if ([self isViewLoaded] && !self.view.window) {self.view = nil;}
}#pragma mark - Table view data source- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
#warning Potentially incomplete method implementation.// Return the number of sections.return 0;
}- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
#warning Incomplete method implementation.// Return the number of rows in the section.return 0;
}/*
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:<#@"reuseIdentifier"#> forIndexPath:indexPath];// Configure the cell...return cell;
}
*//*
// Override to support conditional editing of the table view.
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath {// Return NO if you do not want the specified item to be editable.return YES;
}
*//*
// Override to support editing the table view.
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {if (editingStyle == UITableViewCellEditingStyleDelete) {// Delete the row from the data source[tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];} else if (editingStyle == UITableViewCellEditingStyleInsert) {// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view}
}
*//*
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath {
}
*//*
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath {// Return NO if you do not want the item to be re-orderable.return YES;
}
*//*
#pragma mark - Navigation// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {// Get the new view controller using [segue destinationViewController].// Pass the selected object to the new view controller.
}
*/@end

#import <UIKit/UIKit.h>@interface UIImage (Scale)
//获取指定大小的图片
-(UIImage *)scaleToSize:(CGSize)size;
@end

#import "UIImage+Scale.h"@implementation UIImage (Scale)
-(UIImage *)scaleToSize:(CGSize)size{//绘制图片//创建一个 bitmap 的上下文，并指定为当前使用的 context
    UIGraphicsBeginImageContext(size);//根据外界传入的大小绘制改变大小后的图片[self drawInRect:CGRectMake(0, 0, size.width, size.height)];//从当前的 context 获取改变大小后的图片UIImage * scaleImage = UIGraphicsGetImageFromCurrentImageContext();//使我们当前的 context 从栈顶出栈
    UIGraphicsEndImageContext();//返回改变大小后的图片return scaleImage;
}
@end

#import <UIKit/UIKit.h>@interface UIImage (Scale)
//获取指定大小的图片
-(UIImage *)scaleToSize:(CGSize)size;
@end

#import "UIImage+Scale.h"@implementation UIImage (Scale)
-(UIImage *)scaleToSize:(CGSize)size{//绘制图片//创建一个 bitmap 的上下文，并指定为当前使用的 context
    UIGraphicsBeginImageContext(size);//根据外界传入的大小绘制改变大小后的图片[self drawInRect:CGRectMake(0, 0, size.width, size.height)];//从当前的 context 获取改变大小后的图片UIImage * scaleImage = UIGraphicsGetImageFromCurrentImageContext();//使我们当前的 context 从栈顶出栈
    UIGraphicsEndImageContext();//返回改变大小后的图片return scaleImage;
}
@end