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