9.19. Use of table view

The IOS table view consists of cells (generally reusable) that display views scrolling vertically.

In iOS, the table view is used to display a list of data, such as a list of contacts, to-dos, or shopping items.

9.19.1. Important attribute ¶

Delegate
DataSource
RowHeight
SectionFooterHeight
SectionHeaderHeight
SeparatorColor
TableHeaderView
TableFooterView

An important method ¶

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

- (void)deleteRowsAtIndexPaths:(NSArray *)indexPaths
   withRowAnimation:(UITableViewRowAnimation)animation

- (id)dequeueReusableCellWithIdentifier:(NSString *)identifier

- (id)dequeueReusableCellWithIdentifier:(NSString *)identifier
  forIndexPath:(NSIndexPath *)indexPath

- (void)reloadData

- (void)reloadRowsAtIndexPaths:(NSArray *)indexPaths
   withRowAnimation:(UITableViewRowAnimation)animation

- (NSArray *)visibleCells

9.19.2. Sample code and steps ¶

1.在ViewController.xib中添加表格视图，如下所示

two。 Set the delegate and data source to File’s Owner (owner of the file) by right-clicking and selecting the data source and delegate. Set up the data source as follows

3.为表格视图创建IBOutlet的并将其命名为myTableView。如以下图片中所示

To own the data, add a NSMutableArray so that it can be displayed in the list grid view

5.ViewController应采用的UITableViewDataSource和UITableViewDelegate协议。ViewController.h代码如下所示

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController<UITableViewDataSource,
UITableViewDelegate>
{

    IBOutlet UITableView *myTableView;
    NSMutableArray *myData;
}

@end

6.执行所需的表格视图委托和数据源的方法。更新ViewController.m，如下所示

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // table view data is being set here
    myData = [[NSMutableArray alloc]initWithObjects:
    @"Data 1 in array",@"Data 2 in array",@"Data 3 in array",
    @"Data 4 in array",@"Data 5 in array",@"Data 5 in array",
    @"Data 6 in array",@"Data 7 in array",@"Data 8 in array",
    @"Data 9 in array", nil];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table View Data source
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:
  (NSInteger)section{
    return [myData count]/2;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:
  (NSIndexPath *)indexPath{
    static NSString *cellIdentifier = @"cellID";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:
    cellIdentifier];
    if (cell == nil) {
        cell = [[UITableViewCell alloc]initWithStyle:
        UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
    }
    NSString *stringForCell;
    if (indexPath.section == 0) {
        stringForCell= [myData objectAtIndex:indexPath.row];

    }
    else if (indexPath.section == 1){
        stringForCell= [myData objectAtIndex:indexPath.row+ [myData count]/2];

    }
    [cell.textLabel setText:stringForCell];
    return cell;
}

// Default is 1 if not implemented
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
    return 2;
}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:
  (NSInteger)section{
    NSString *headerTitle;
    if (section==0) {
        headerTitle = @"Section 1 Header";
    }
    else{
        headerTitle = @"Section 2 Header";

    }
    return headerTitle;
}
- (NSString *)tableView:(UITableView *)tableView titleForFooterInSection:
  (NSInteger)section{
    NSString *footerTitle;
    if (section==0) {
        footerTitle = @"Section 1 Footer";
    }
    else{
        footerTitle = @"Section 2 Footer";

    }
    return footerTitle;
}

#pragma mark - TableView delegate

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:
 (NSIndexPath *)indexPath{
    [tableView deselectRowAtIndexPath:indexPath animated:YES];
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    NSLog(@"Section:%d Row:%d selected and its data is %@",
    indexPath.section,indexPath.row,cell.textLabel.text);
}


@end

7.现在当我们运行应用程序时我们就会得到下面的输出