表格视图的使用

IOS表格视图由单元格 （一般可重复使用） 组成，用于显示垂直滚动的视图。

在iOS 中,表格视图用于显示数据列表,如联系人、待办事项或购物项列表。

重要的属性

• delegate
• dataSource
• rowHeight
• sectionFooterHeight
• sectionHeaderHeight
• separatorColor
• tableHeaderView
• tableFooterView

重要的方法

- (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

示例代码和步骤

1.在ViewController.xib中添加表格视图，如下所示

2. 通过右键单击并选择数据源和委托将委托和数据源设定到"File's Owner（文件的所有者）"。设置数据源如下所示

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

4. 为拥有数据，添加一个NSMutableArray使其能够在列表格视图中显示

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