子类化UITableViewCell后,Label不会显示文本

时间:2011-07-24 06:36:16

标签: iphone ios uitableview

所以我知道这被问了一百万次。也许我太累了,但我无法弄清楚为什么这个标签文字不会更新。继承人我的代码

CustomCell.h

#import <UIKit/UIKit.h>


@interface CustomCell : UITableViewCell {
    UILabel *mainLabel; 
    UILabel *leftBottomLabel;
    UILabel *rightBottomLabel;

}


@property (nonatomic, retain) UILabel *mainLabel;
@property (nonatomic, retain) UILabel *leftBottomLabel;
@property (nonatomic, retain) UILabel *rightBottomLabel;


@end

CustomCell.m

#import "CustomCell.h"


@implementation CustomCell

@synthesize mainLabel;
@synthesize leftBottomLabel; 
@synthesize rightBottomLabel;



-(id) initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier {

    if (self = [super initWithStyle:style reuseIdentifier:reuseIdentifier]) {
        // Initialization code


        UIView *myContentView = self.contentView;



        self.mainLabel.textAlignment = UITextAlignmentLeft; 
        [myContentView addSubview:self.mainLabel];
        [self.mainLabel release];



        self.leftBottomLabel.textAlignment = UITextAlignmentLeft; 
        [myContentView addSubview:self.leftBottomLabel];
        [self.leftBottomLabel release];


        self.rightBottomLabel.textAlignment = UITextAlignmentLeft; // default
        [myContentView addSubview:self.rightBottomLabel];
        [self.rightBottomLabel release];
    }


    return self;
}


- (void)layoutSubviews {

    [super layoutSubviews];


    CGRect contentRect = self.contentView.bounds;
    CGFloat boundsX = contentRect.origin.x;
    CGRect frame;


        frame = CGRectMake(boundsX + 10, 4, 200, 20);
        self.mainLabel.frame = frame;
        self.mainLabel.backgroundColor = [UIColor redColor];

        frame = CGRectMake(boundsX + 10, 28, 200, 20);
        self.leftBottomLabel.frame = frame;
        self.leftBottomLabel.backgroundColor = [UIColor greenColor];


        frame = CGRectMake(boundsX + 100, 28, 200, 14);
        self.rightBottomLabel.frame = frame;
        self.rightBottomLabel.backgroundColor = [UIColor blueColor];

}



- (void)dealloc {

    [mainLabel dealloc];
    [leftBottomLabel dealloc];
    [rightBottomLabel dealloc];
    [super dealloc];
}

@end

MyView.m

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

    static NSString *CellIdentifier = @"Cell";

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

    cell.mainLabel.text = @"Hello";
return cell;
}

有什么想法?我没有在这个标签中得到任何东西,不知道为什么。

2 个答案:

答案 0 :(得分:3)

您需要先创建每个三个标签,然后才能更改其属性或进行任何屏幕绘制。目前,这三个标签仅被宣布。要解决此问题,请在initWithStyle:reuseIdentifier:中,在顶部添加以下内容:

self.mainLabel = [[UILabel alloc] init];
self.leftBottomLabel = [[UILabel alloc] init];
self.rightBottomLabel = [[UILabel alloc] init];

您的layoutSubviews代码将处理框架更改(这就是您不需要[[UILabel alloc] initWithFrame..]初始化的原因,因为您在适当的时候自己设置了框架),现在应该显示您的标签正确。

答案 1 :(得分:1)

您似乎永远不会真正创建标签。

你需要一个

mailLabel = [[UILabel alloc] initwithframe...]
在你的初始化代码中