檢測哪個按鈕需要修改文本在細胞

Question

我有一個按鈕，在tableviewcell

- (UITableViewCell *) tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{ 

    static NSString *CellIdentifier = @"Cell"; 

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; 


    if (!cell) { 
     cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:nil]; 

     DBImageView *imageView = [[DBImageView alloc] initWithFrame:(CGRect){ 0, 0, 320, 320 }]; 
     [imageView setPlaceHolder:[UIImage imageNamed:@"Placeholder"]]; 
     [imageView setTag:101]; 
     [cell.contentView addSubview:imageView]; 
    } 


    NSDictionary *tmpDict = [myObject objectAtIndex:indexPath.row]; 
    [(DBImageView *)[cell viewWithTag:101] setImageWithPath:[tmpDict objectForKey:@"thumb_link"]]; 


    likeButton = [UIButton buttonWithType:UIButtonTypeCustom] ; 
    [likeButton setFrame:CGRectMake(cell.frame.size.width-60,280,81,33)]; 
    likeButton.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter; 
    likeButton.contentEdgeInsets = UIEdgeInsetsMake(3, 2, 0, 0); 
    [likeButton.titleLabel setFont:[UIFont fontWithName:@"Trebuchet MS" size:16]]; 
    [likeButton setBackgroundImage:[UIImage imageNamed:@"heart.png"] forState:UIControlStateNormal]; 
    [likeButton setBackgroundImage:[UIImage imageNamed:@"heart_pressed.png"] forState:UIControlStateSelected]; 
    [cell addSubview:likeButton]; 


    // like button 
    likeButton.selected = ![likeButton isSelected]; 
    NSInteger defaultKey2 = [[NSUserDefaults standardUserDefaults] integerForKey:[tmpDict objectForKey:@"id"]]; 
    if (defaultKey2 == 0) 
    { 
     //[likeButton setTitleColor:[UIColor colorWithRed:255/255.0 green:255/255.0 blue:255/255.0 alpha:1.0] forState:UIControlStateNormal]; 
     [likeButton setSelected:NO]; 
    } 
    else if (defaultKey2 == 1) 
    { 
     //[likeButton setTitleColor:[UIColor colorWithRed:229/255.0 green:85/255.0 blue:140/255.0 alpha:1.0] forState:UIControlStateNormal]; 
     [likeButton setSelected:YES]; 
    } 


    [likeButton setTitle:[tmpDict objectForKey:@"likes"] forState:UIControlStateNormal]; 
    [likeButton addTarget:self action:@selector(like:) forControlEvents: UIControlEventTouchUpInside]; 
    [likeButton setTag:indexPath.row]; 

    return cell; 

} 

這是我的行動：

-(void)like:(id) sender{ 
    UIButton *likebtn = (UIButton *)sender; 
    NSDictionary *tmpDict = myObject[likebtn.tag]; 
    NSInteger defaultKey2 = [[NSUserDefaults standardUserDefaults] integerForKey:[tmpDict objectForKey:@"id"]]; 
    if (defaultKey2 == 0) 
    { 
     //Increase value 
     int varTemp = [[tmpDict objectForKey:@"likes"] intValue]+1; 
     NSString *strValue = [NSString stringWithFormat:@"%d", varTemp]; 
     [likeButton setTitle:strValue forState:UIControlStateNormal]; 
     NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults]; 
     [prefs setInteger:1 forKey:[tmpDict objectForKey:@"id"]]; 
     [[NSUserDefaults standardUserDefaults]synchronize]; 
    } 
    if (defaultKey2 == 1) 
    { 
     //Decrease value 
     int varTemp = [[tmpDict objectForKey:@"likes"] intValue]-1; 
     NSString *strValue = [NSString stringWithFormat:@"%d", varTemp]; 
     [likeButton setTitle:strValue forState:UIControlStateNormal]; 
     NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults]; 
     [prefs setInteger:0 forKey:[tmpDict objectForKey:@"id"]]; 
     [[NSUserDefaults standardUserDefaults]synchronize];  
    } 
    NSIndexPath *tmpIndexpath=[NSIndexPath indexPathForRow:likebtn.tag inSection:0]; 
    [self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:tmpIndexpath, nil] withRowAnimation:UITableViewRowAnimationNone]; 
} 

當我嘗試在細胞 設置標題爲我的按鈕[likeButton setTitle:strValue forState:UIControlStateNormal];值錯誤的單元格。

如何檢測單元值中的哪個按鈕需要設置？我如何使用我的標籤？

Answer 1

您不能設置按鈕標題這樣在你like:方法，即：

[likeButton setTitle:strValue forState:UIControlStateNormal]; 

（1）因爲你重裝右表事後從而觸發手動調用cellForRowAtIndexPath:和（2 ），即使您沒有重新載入表格數據，即使滾動也會觸發cellForRowAtIndexPath的調用，因此您的單元格將根據cellForRowAtIndexPath:的信息進行填充。

目前的情況是，你cellForRowAtIndexPath:方法是使用下面的行設置標題：

[likeButton setTitle:[tmpDict objectForKey:@"likes"] forState:UIControlStateNormal]; 

這意味着，爲了使like:動作來觸發標題的變化，你必須改變[ tmpDict objectForKey：@「likes」]值爲like:。由於您使用的是臨時字典，並且絕不會將字典添加回myObject數組中，所以您沒有更改最終決定您的按鈕標題的值爲cellForRowAtIndexPath:。所以你必須相應地更新myObject。這裏是我的代碼的建議：

-(void)like:(id)sender { 

    UIButton *likebtn = (UIButton *)sender; 
    NSMutableDictionary *tmpDict = myObject[likebtn.tag]; 
    NSInteger defaultKey2 = [[NSUserDefaults standardUserDefaults] integerForKey:[tmpDict objectForKey:@"id"]]; 

    if (defaultKey2 == 0) 
    { 
     //Increase value 
     int varTemp = [[tmpDict objectForKey:@"likes"] intValue]+1; 

     // Then update myObject 
     [tmpDict setObject:[NSString stringWithFormat:@"%d", varTemp] forKey:@"likes"]; 
     [myObject replaceObjectAtIndex:likebtn.tag withObject:tmpDict]; 

     NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults]; 
     [prefs setInteger:1 forKey:[tmpDict objectForKey:@"id"]]; 
     [[NSUserDefaults standardUserDefaults]synchronize]; 
    } 
    if (defaultKey2 == 1) 
    { 
     //Decrease value 
     int varTemp = [[tmpDict objectForKey:@"likes"] intValue]-1; 

     // Then update myObject 
     [tmpDict setObject:[NSString stringWithFormat:@"%d", varTemp] forKey:@"likes"]; 
     [myObject replaceObjectAtIndex:likebtn.tag withObject:tmpDict]; 


     NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults]; 
     [prefs setInteger:0 forKey:[tmpDict objectForKey:@"id"]]; 
     [[NSUserDefaults standardUserDefaults]synchronize];  
    } 

    NSIndexPath *tmpIndexpath=[NSIndexPath indexPathForRow:likebtn.tag inSection:0]; 
    [self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObjects:tmpIndexpath, nil] withRowAnimation:UITableViewRowAnimationNone]; 

} 

編輯：也有現在是一個很大的問題，我已經看到你的cellForRowAtIndexPath:方法。你已經將該按鈕聲明爲一個類變量？ （1）不要這樣做。保持它的地方，例如：

UIButton *likeButton = [UIButton buttonWithType:UIButtonTypeCustom] ; 

（2）你重用你的細胞，但每次添加一個新的按鈕。所以你要在另一個頂部添加一個按鈕，每個按鈕都要撥打cellForRowAtIndexPath:。這可能會導致你前進的問題。

Answer 2

您的手機可能會重複使用按鈕，並且標記可能會混亂。 嘗試在tableView：willDisplayCell：forRowAtIndexPath：方法中刷新bouttons的標籤。