未能正确声明/实现 UITableViewDataSource 方法 [英] Failing to properly declare/implement UITableViewDataSource methods

问题描述

我有一个 UIViewController，我想用它来实现 UITableViewDataSource 的方法.我有这个标题，FriendsController.h:

I have a UIViewController that I want to use to implement the methods of UITableViewDataSource on. I have this header, FriendsController.h:

#import <UIKit/UIKit.h>
@interface FriendsController : UIViewController <UITableViewDataSource>
@end

现在将@interface声明更新为:

@interface FriendsController : UIViewController <UITableViewDataSource, UITableViewDelegate>

和这个实现，FriendsController.m:

#import "FriendsController.h"

@implementation FriendsController

- (NSInteger)tableView:(UITableView *)tableView 
numberOfRowsInSection:(NSInteger)section
{
  // Return the number of rows in the section.
  NSLog(@"CALLED .numberOfRowsInSection()");
  return 1;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
  NSLog(@"CALLED cellForRowAtIndexPath()");
  UITableViewCell *cell = [tableView
                             dequeueReusableCellWithIdentifier:@"FriendCell"];
  cell.textLabel.text = @"Testing label";
  return cell;
}
@end

运行时，这给了我一个-[UIView tableView:numberOfRowsInSection:]: unrecognized selector sent to instance 0x81734d0".谁能看看我对 .numberOfRowsInSection() 的实现/声明是否有问题?

When run this gives me a '-[UIView tableView:numberOfRowsInSection:]: unrecognized selector sent to instance 0x81734d0'. Can anyone see if there is something wrong with my implementation/declaration of .numberOfRowsInSection()?

我从 here 并运行视图未连接"，它输出以下列表:

I've added a technique for method listing from here and run the view 'unconnected', it outputs the following list:

[<timestamp etc>] Method no #0: tableView:numberOfRowsInSection:
[<timestamp etc>] Method no #1: tableView:cellForRowAtIndexPath:
[<timestamp etc>] Method no #2: numberOfSectionsInTableView:
[<timestamp etc>] Method no #3: tableView:didSelectRowAtIndexPath:
[<timestamp etc>] Method no #4: viewDidLoad

发布脚本:@ThisDarkTao 和 @Pei 都做对了，从我之前记录视觉部分的问题中可以看出，此处.

Post scriptum: Both @ThisDarkTao and @Pei got it right, as can be seen in my previous question documenting the visual parts, here.

推荐答案

需要在接口文件中的协议列表中添加UITableViewDelegate，像这样:<UITableViewDataSource, UITableViewDelegate>

You need to add UITableViewDelegate to the list of protocols in the interface file, like this: <UITableViewDataSource, UITableViewDelegate>

您还需要以下所有委托方法:

You also need all of the following delegate methods:

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return 1; // Number of rows
}

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

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }

    cell.textLabel.text = @"Test Cell";

    return cell;
}

在您的 xib/storyboard 视图中，您还需要将 tableview 的委托和数据源连接连接到 viewcontroller.

In your xib/storyboard view, you also need to connect the tableview's delegate and datasource connections to the viewcontroller.

如果你想让你的单元格在你点击它们时做某事"，你还需要实现以下委托方法:

If you want your cells to 'do something' when you tap them, you also need to implement the following delegate method:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"Tapped cell %d",indexPath.row);     
}

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