Master-Detail应用背景

Question

我的主-细节应用程序背景有点问题。当我启动应用程序而不是显示我设置的背景图片时，它会显示以下内容：

​

当我按下add按钮时，它会变成真实的背景：

​

这是我使用的代码：

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        self.title = NSLocalizedString(@"Master", @"Master");
    }

    return self;
}

- (void)viewDidLoad
{

        [super viewDidLoad];

    bgView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
    bgView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"textured_paper.png"]];


    // Do any additional setup after loading the view, typically from a nib.
    self.navigationItem.leftBarButtonItem = self.editButtonItem;

    UIBarButtonItem *addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(insertNewObject:)];
    self.navigationItem.rightBarButtonItem = addButton;
}

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

- (void)insertNewObject:(id)sender
{
    if (!_objects) {
        _objects = [[NSMutableArray alloc] init];
    }
    [_objects insertObject:[NSDate date] atIndex:0];
    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
    [self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}

#pragma mark - Table View

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

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return _objects.count;
}

// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    tableView.backgroundView = bgView;
    static NSString *CellIdentifier = @"Cell";
    tableView.separatorColor = [UIColor colorWithHue:0 saturation:0 brightness:33 alpha:0.2];
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;


    }

    cell.textLabel.textColor = [UIColor whiteColor];
    cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"Cell.png"]];
    cell.textLabel.backgroundColor = [UIColor clearColor];

    NSDate *object = _objects[indexPath.row];
    cell.textLabel.text = [object description];
    return cell;
}

- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Return NO if you do not want the specified item to be editable.
    return YES;
}

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

    if (editingStyle == UITableViewCellEditingStyleDelete) {
        [_objects removeObjectAtIndex:indexPath.row];
        [tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
    } else if (editingStyle == UITableViewCellEditingStyleInsert) {
        // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view.
    }
}

/*
// Override to support rearranging the table view.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath
{
}
*/

/*
// Override to support conditional rearranging of the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Return NO if you do not want the item to be re-orderable.
    return YES;
}
*/

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (!self.detailViewController) {
        self.detailViewController = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil];
    }
    NSDate *object = _objects[indexPath.row];
    self.detailViewController.detailItem = object;
    [self.navigationController pushViewController:self.detailViewController animated:YES];
}

我怎么才能让它直接显示背景图像呢？谢谢。

Answer 1

不需要创建另一个视图，只需将其放入viewDidLoad即可

self.tableView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"textured_paper.png"]];
self.tableView.backgroundView = nil;

去掉这些

//in viewDidLoad
bgView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
bgView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"textured_paper.png"]];
//in cellForRowAtIndexPath:
tableView.backgroundView = bgView;

或者试着把

tableView.backgroundView = bgView;

在viewDidLoad中，它应该可以工作。

出现此问题的原因是，您在设置单元格时调用的方法中设置了tableView的backgroundView，但是因为表视图中还没有单元格，所以只有在视图中至少有一个单元格时，才会调用该方法。