UI学习笔记---第十天UITableView表视图编辑

UITableView表视图编辑

表视图编辑的使用场景

当我们需要手动添加或者删除某条数据到tableView中的时候,就可以使用tableView编辑.比如微信 扣扣中删除和某人的通话

当我们需要手动调整单元格的顺序时,就可以通过tableView移动,移动单元格到指定位置

代理AppDelegate.m中代码

#import "AppDelegate.h"

#import "RootViewController.h"

@implementation AppDelegate

-(void)dealloc

{

    [_window release];

    [super dealloc];

}

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

{

    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];

    // Override point for customization after application launch.

    self.window.backgroundColor = [UIColor whiteColor];

    

    RootViewController *rootVC = [[RootViewController alloc] init];

    UINavigationController *ngVC = [[UINavigationController alloc] initWithRootViewController:rootVC];

    self.window.rootViewController = ngVC;

    

    [ngVC release];

    [rootVC release];



    [self.window makeKeyAndVisible];

    return YES;

}

RootViewController.h中建立一个可变数组属性 

 NSMutableArray *_mArr;

RootViewController.m中初始化和loadView代码

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

{

    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

    if (self) {

        self.navigationItem.title = @"百家讲坛";

        self.navigationItem.rightBarButtonItem = self.editButtonItem;//控制器自带的编辑按钮

        _mArr = [[NSMutableArray alloc] initWithObjects:@"赵",@"钱",@"孙",@"李",@"周",@"武",@"郑",@"王",@"唐僧",@"孙悟空",@"猪八戒",@"沙僧",@"小白龙",@"二郎神",@"哪吒",@"雷震子", nil];

        // Custom initialization

    }

    return self;

}

-(void)loadView

{

    

    UITableView *table = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, 320, 480) style:UITableViewStyleGrouped];

    table.dataSource = self;

    table.delegate = self;

    self.view = table;

    [table release];



}

 

 

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

    return [_mArr count];

}



- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{

    static NSString *identifier = @"reuse";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];

    if (cell == nil) {

        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier];

    }

    cell.textLabel.text = [_mArr objectAtIndex:indexPath.row];

//    tableView.editing = YES;

    //cell右侧属性

    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

    return cell;

}

 

编辑的步骤

1.让tableView处于编辑状态

-(void)setEditing:(BOOL)editing animated:(BOOL)animated

{

    //调用父类方法,实现edit和done的变换

    [super setEditing:editing animated:animated];

    UITableView *tableView = (UITableView *)self.view;

    [tableView setEditing:editing animated:animated];

}

2.指定tableView那些行可以编辑

 //设置cell的可编辑状态,默认是yes

- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath

{

//    if (indexPath.row == 0) {

//        return YES;

//    }

    return YES;

}

3.指定tableView的编辑的样式(添加.删除)

//delegate中得方法

- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath

{

    if (indexPath.row ==0) {

        return UITableViewCellEditingStyleInsert;//添加

    }

    return UITableViewCellEditingStyleDelete;//删除

}

4.编辑完成(先操作数据源,后修改UI)

//点击加号或者delete时触发的事件

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath

{

    if (editingStyle == UITableViewCellEditingStyleDelete) {

        [tableView beginUpdates];

        //删除数据  (写在删除cell前面  或者写一个[tableView beginUpdates]放前面一个[tableView endUpdates]放后面)

        [_mArr removeObjectAtIndex:indexPath.row];

        //删除cell

        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationRight];

        [tableView endUpdates];

        NSLog(@"删除");

    }else{

        [tableView beginUpdates];

        [_mArr insertObject:@"hello" atIndex:indexPath.row];

        [tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationRight];

        [tableView endUpdates];

        

        NSLog(@"添加");

    }

}

表视图的移动

移动的步骤

1.让tableView处于编辑状态

-(void)setEditing:(BOOL)editing animated:(BOOL)animated

{

    //调用父类方法,实现edit和done的变换

    [super setEditing:editing animated:animated];

    UITableView *tableView = (UITableView *)self.view;

    [tableView setEditing:editing animated:animated];

}

2.指定tableView哪些行可以移动

-(BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath

{

    return YES;

}

3.移动完成

- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath

{

    NSString *str = [_mArr objectAtIndex:sourceIndexPath.row];

    

    //引用计数加1.避免出现野指针

    [str retain];

    

    

    //删除元素

    [_mArr removeObjectAtIndex:sourceIndexPath.row];

    //插入元素

    [_mArr insertObject:str atIndex:destinationIndexPath.row];

    

    [str release];//释放之前,retain的对象

}

监测移动过程,实现限制跨区移动

- (NSIndexPath *)tableView:(UITableView *)tableView targetIndexPathForMoveFromRowAtIndexPath:(NSIndexPath *)sourceIndexPath toProposedIndexPath:(NSIndexPath *)proposedDestinationIndexPath

{

    NSLog(@"%d",sourceIndexPath.row);

    NSLog(@"%d",proposedDestinationIndexPath.row);

    if (sourceIndexPath.row == [_mArr count]-1) {

        return sourceIndexPath;

    }else{

    return proposedDestinationIndexPath;

    }

}

UITableViewController表视图控制器

继承自UIViewController

自带一个tableView,根视图就是tableView

模板自带编辑移动相关的代码