ios - 如何使用 UItableViewCell reuseIdentifier

Question

我想使用 UITableviewCell 重用，我有一个自定义的 UITableViewCell 和使用 ARC，我的 UITableViewCell 是不同的。我的代码是:

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

PostCount *post=[listArr objectAtIndex:indexPath.row];

static NSString *CellIdentifier = @"TimeLineViewCell";

TimeLineViewCell *cell = (TimeLineViewCell*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell==nil){

    cell = [[TimeLineViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"CellIdentifier11"];
}
cell.tag=indexPath.row+1000;
cell.lab_time.text=[ModelClass intervalSinceNow:post.when btime:0];
cell.delegate=self;
[cell setViewStyle:post];
post=nil;
return cell;
}

你知道我用过吗

cell = [[TimeLineViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] 

代替

cell = [[TimeLineViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"CellIdentifier11"]; 

我的手机总是在错误的位置。为什么我不能使用相同的 reuseIdentifier。如果我使用不同的 reuseIdentifier，如果我的 cell 没有被重用。

对于其他 Viewcontroller View ，当单元格的高度相同且我使用相同的 reuseIdentifier 时一切正常。谁能帮我解决这个问题？

编辑:我的自定义单元格代码:

#import "TimeLineViewCell.h"

@implementation TimeLineViewCell



- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
    if (self) {

        imageView_t=[[UIImageView alloc]initWithFrame:CGRectMake(5, 5, 40, 40)];
        imageView_t.hidden=YES;




        imageIcon=[[UIImageView alloc]initWithFrame:CGRectMake(295, 5, 16, 16)];




        self.lab_time = [[UILabel alloc] initWithFrame:CGRectMake(210, 5, 80, 20)];
        self.lab_time.textColor=[UIColor grayColor];
        self.lab_time.font=[UIFont systemFontOfSize:12];
        self.lab_time.textAlignment=UITextAlignmentRight;
        self.lab_time.backgroundColor=[UIColor clearColor];



        whoscreenName = [[UILabel alloc] initWithFrame:CGRectMake(60, 5, 145, 20)];
        whoscreenName.textColor=[UIColor blackColor];
        whoscreenName.font=[UIFont systemFontOfSize:18];
        whoscreenName.lineBreakMode = UILineBreakModeTailTruncation;
        whoscreenName.numberOfLines = 0;
        whoscreenName.backgroundColor=[UIColor clearColor];



        myWhat = [[UITextView alloc] init];
        myWhat.textColor=[UIColor blackColor];

        myWhat.backgroundColor=[UIColor clearColor];
        [myWhat setScrollEnabled:NO];
        [myWhat setEditable:NO];
        myWhat.dataDetectorTypes=UIDataDetectorTypeLink;
        [myWhat setCanCancelContentTouches:NO];


        self.myWhaticon=[[UIView alloc]init];



        myImageView=[[UIImageView alloc]init];
        myImageView.hidden=YES;




        myIndicatorView=[[UIActivityIndicatorView alloc ]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
        myIndicatorView.hidden=YES;



        whoBgView=[[UIImageView alloc]init];

        whoBgView.image = [[UIImage imageNamed:@"timeline_rt_border_t.png"] stretchableImageWithLeftCapWidth:130 topCapHeight:7];




        whoWhat = [[UITextView alloc] init];
        whoWhat.textColor=[UIColor blackColor];

        whoWhat.backgroundColor=[UIColor clearColor];
        [whoWhat setScrollEnabled:NO];
        [whoWhat setEditable:NO];

        whoWhat.dataDetectorTypes=UIDataDetectorTypeLink;//url
        [whoWhat setCanCancelContentTouches:NO];



        whoImageView=[[UIImageView alloc]init];
        whoImageView.hidden=YES;

        activityIndicatorView=[[UIActivityIndicatorView alloc ]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];

        activityIndicatorView.hidden=YES;



        myWhat.font=[UIFont systemFontOfSize:15];
        whoWhat.font=[UIFont systemFontOfSize:14];




    }
    return self;
}

- (void)setSelected:(BOOL)selected animated:(BOOL)animated
{
    [super setSelected:selected animated:animated];

    // Configure the view for the selected state
}


- (void)layoutSubviews
{
    [super layoutSubviews];

     [self addSubview:imageView_t];
    [self addSubview:imageIcon];
     [self addSubview: self.lab_time];
    [self addSubview:whoscreenName];
     [self addSubview:myWhat];
    [self addSubview:self.myWhaticon];
    [self addSubview:myImageView];
    [self addSubview:myIndicatorView]; 
    [self addSubview:whoBgView];

    [whoBgView addSubview:whoWhat];
    [whoBgView addSubview:whoImageView];
    [whoBgView addSubview: activityIndicatorView];


    whoImageView=nil;
    whoWhat=nil;
}

-(void)my_imag_btnClick:(UIButton *)btn{

    [self.delegate my_imag_btnClick:btn.tag];

}


-(void)who_imag_btnClick:(UIButton *)btn{
     NSLog(@"who_imag_btnClick");
    [self.delegate who_imag_btnClick:btn.tag];

}

- (void)dealloc
{
    imageView_t.image=nil;
    imageView_t=nil;

    imageIcon.image=nil;
    imageIcon=nil;

    whoscreenName=nil;

    self.lab_time=nil;
    whoscreenName=nil;
    myWhat=nil;

    self.myWhaticon=nil;
    myImageView.image=nil;
    myImageView=nil;

    whoBgView.image=nil;
    whoBgView=nil;

    whoImageView.image=nil;
    whoImageView=nil;

}

-(void)setViewStyle:(PostCount *)post{

    //时间
    if (self.btime==1) {
        self.lab_time.text=[ModelClass intervalSinceNow:post.when btime:1 ];
    }else{
        self.lab_time.text=[ModelClass intervalSinceNow:post.when btime:0];
    }

    imageView_t.hidden=NO;

    //     imageView_t.isRoundIcon=YES;
    imageView_t.layer.cornerRadius = 5;
    imageView_t.layer.masksToBounds = YES;
    //给图层添加一个有色边框
    imageView_t.layer.borderWidth = 0.8;
    imageView_t.layer.borderColor = [[UIColor colorWithRed:230.0/255 green:230.0/255 blue:230.0/255 alpha:1.0] CGColor];

    if(![GlobalVariable isBlankString:post.who.avatarbig])
    {


        [imageView_t setImageWithURL:[NSURL URLWithString:post.who.avatarbig]
                    placeholderImage:[UIImage imageNamed:@"default_user.png"]];

    }
    else{
        imageView_t.image=[UIImage imageNamed:@"default_user.png"];
    }



    //icon
    imageIcon.image=[UIImage imageNamed:[ModelClass returnimage_source:post.source]];
    whoscreenName.text=post.who.screenName;



    CGSize size_myWhat =[ModelClass heightForTextView:[UIFont systemFontOfSize:15] WithText:post.what weith:250];


    myWhat.frame=CGRectMake(50, 25, 250, size_myWhat.height);
    myWhat.text=[NSString stringWithFormat:@"%@",post.what];
    self.myWhaticon.frame=myWhat.frame;


    if(![GlobalVariable isBlankString:post.img_small])
    {

        CGSize size_myImageView=CGSizeMake(80, 80);

        myImageView.frame=CGRectMake(50, 30+size_myWhat.height, size_myImageView.width, 80);
        myImageView.hidden=NO;


        myIndicatorView.center=myImageView.center;
        myIndicatorView.hidden=NO;
        [myIndicatorView startAnimating];
        __block UIActivityIndicatorView *indicatorView=myIndicatorView;

        __block UIImageView *myImage = myImageView;
        [myImageView setImageWithURL:[NSURL URLWithString:post.img_small]
                    placeholderImage:nil
                             success:^(UIImage *image){

                                 CGRect  sFrame=myImage.frame;
                                 //缩放
                                 CGSize newSize=image.size;

                                 if (newSize.height>80) {
                                     newSize.height=80;
                                     newSize.width=newSize.width*80.0/image.size.height;

                                 }else{
                                     if (newSize.width>80) {
                                         newSize.height=newSize.height *80.0/image.size.width;
                                         newSize.width=80;
                                     }else{//2个都小于80
                                         newSize.height=newSize.height;
                                         newSize.width=newSize.width;

                                     }

                                 }
                                 sFrame.size=newSize;
                                 myImage.frame=sFrame;

                                 indicatorView.hidden=YES;
                                 [indicatorView stopAnimating];
                                 [indicatorView removeFromSuperview];
                             }
                             failure:^(NSError *error){
                                 indicatorView.hidden=YES;
                                 [indicatorView stopAnimating];
                                 [indicatorView removeFromSuperview];
                             }];


        UIButton * myImageBtn=[[UIButton alloc]init];
        myImageBtn.frame= CGRectMake(50, 30+size_myWhat.height, size_myImageView.width, 80);
        [myImageBtn addTarget:self action:@selector(my_imag_btnClick:) forControlEvents:UIControlEventTouchUpInside];
        myImageBtn.tag=self.tag-1000;
        //        myImageBtn.backgroundColor=[UIColor blueColor];
        [self addSubview:myImageBtn ];


    }


    if ([post.sourceTweet.what length]>0) {
        whoWhat.text=[NSString stringWithFormat:@"@%@: %@",post.sourceTweet.who.screenName,post.sourceTweet.what];

    }

    CGSize size_whoWhat =[ModelClass heightForTextView:[UIFont systemFontOfSize:14] WithText:whoWhat.text weith:250];

    whoWhat.frame=CGRectMake(10, 10, 250, size_whoWhat.height);


    if(![GlobalVariable isBlankString:post.sourceTweet.img_small])
    {

        CGSize size_whoImageView=CGSizeMake(80, 80);
        whoImageView.frame=CGRectMake(30, 15+size_whoWhat.height, size_whoImageView.width, 80);
        whoImageView.hidden=NO;

        activityIndicatorView.center=whoImageView.center;
        activityIndicatorView.hidden=NO;
        [activityIndicatorView startAnimating];
          __block UIActivityIndicatorView *indicatorView = activityIndicatorView;

        __block UIImageView *whoImage = whoImageView;


        [whoImageView setImageWithURL:[NSURL URLWithString:post.sourceTweet.img_small]
                     placeholderImage:nil
                              success:^(UIImage *image){

                                  CGRect  sFrame=whoImage.frame;
                                  //缩放
                                  CGSize newSize=image.size;

                                  if (newSize.height>80) {
                                      newSize.height=80;
                                      newSize.width=newSize.width*80.0/image.size.height;

                                  }else{
                                      if (newSize.width>80) {
                                          newSize.height=newSize.height *80.0/image.size.width;
                                          newSize.width=80;
                                      }else{//2个都小于80
                                          newSize.height=newSize.height;
                                          newSize.width=newSize.width;

                                      }

                                  }
                                  sFrame.size=newSize;
                                  whoImage.frame=sFrame;

                                  indicatorView.hidden=YES;
                                  [indicatorView stopAnimating];
                                  [indicatorView removeFromSuperview];

                              }
                              failure:^(NSError *error){
                                  indicatorView.hidden=YES;
                                  [indicatorView stopAnimating];
                                  [indicatorView removeFromSuperview];
                              }];

        UIButton * whoImageBtn=[[UIButton alloc]init];
        int myimageHeight=0;
        if (myImageView.frame.size.height>0) {
            myimageHeight=5+80;
        }
        whoImageBtn.frame=CGRectMake(30+42, 40+size_myWhat.height+size_whoWhat.height+myimageHeight, 80, 80);
        whoImageBtn.backgroundColor=[UIColor clearColor];
        [whoImageBtn addTarget:self action:@selector(who_imag_btnClick:) forControlEvents:UIControlEventTouchUpInside];
        whoImageBtn.tag=self.tag-1000;
        [self addSubview:whoImageBtn ];
    }



    if (size_whoWhat.height<20) {
        whoBgView.hidden=YES;
    }else{

        int myimageHeight=0;
        if (myImageView.frame.size.height>0) {
            myimageHeight=5+80;
        }

        whoBgView.frame=CGRectMake(42, 25+size_myWhat.height+myimageHeight, 270, 20+size_whoWhat.height+whoImageView.frame.size.height);

    }


}


@end

Answer 1

要么不要重复使用单元格，要么给每个单元格一个自定义标识符。

对于自定义标识符，替换为:

static NSString *CellIdentifier = @"TimeLineViewCell";

TimeLineViewCell *cell = (TimeLineViewCell*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if(cell==nil){

    cell = [[TimeLineViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"CellIdentifier11"];
}

用这个:

TimeLineViewCell *cell = (TimeLineViewCell*)[tableView dequeueReusableCellWithIdentifier:[NSString stringWithFormat:@"%i", indexPath.row]];
if(cell==nil){
     cell = [[TimeLineViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:[NSString stringWithFormat:@"%i", indexPath.row]];
}

否则，就是不dequeue，每次都创建一个新的cell。

注意:基于单元格的 indexPath.row 的自定义标识符只有在用户没有进行表格编辑时才有效。如果他们要编辑表格，请不要重复使用这些单元格。