自定义的UITableViewCell创建问题
问题描述：
概述
我创建一个UITableView定制UITableViewCell（iOS中8.4，Objective-C的）。我在Custom Cell中创建了每个项目的IBoutlets。它似乎工作得很好，但随机我的UIButton从自定义单元中消失。
自定义的UITableViewCell创建问题
这里我的cellForRowAtIndexPath代码
-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
linkCell*cell = (linkCell*)[tableView dequeueReusableCellWithIdentifier:@"cell" forIndexPath:indexPath];
if(!cell){
cell = [[linkCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"cell"];
}
cell.contentView.backgroundColor = [UIColor clearColor];
NSDictionary *aDict = [numberOfSections objectAtIndex:indexPath.section];
NSDictionary* info = [[aDict objectForKey:@"Data"]objectAtIndex:indexPath.row];
static float span = 5;
static float dateviewsize = 83;
static float linesize = 1;
static float descriptionsize = 65;
//DAY_NAME
NSString* string = [self getDayNameFromDate:[info valueForKey:@"copied_url_date"]];
cell.lblDayName.text = string;
//DAY_NUMBER
string = [self getDayNumberFromDate:[info valueForKey:@"copied_url_date"]];
cell.lblDayNumber.text = string;
//DAY_TIME
string = [self getTimeFromDate:[info valueForKey:@"copied_url_date"]];
cell.lblDayTime.text = string;
//Link Label
if([[info objectForKey:@"copied_url_title"] isEqualToString:@"nil"]){
string = [NSString stringWithFormat:@"%@",[info valueForKey:@"copied_url"]];
cell.lblLink.font = [UIFont fontWithName:FONT_LIGHT size:14];
cell.lblLink.textColor = [UIColor colorWithRed:51.0/255.0 green:0/255.0 blue:135.0/255.0 alpha:1.0];
}else{
string = [NSString stringWithFormat:@"%@",[info objectForKey:@"copied_url_title"]];
cell.lblLink.font = [UIFont fontWithName:FONT_MEDIUM size:16];
cell.lblLink.textColor = [UIColor darkGrayColor];
}
cell.lblLink.text = string;
float w,h,y;
w = self.view.frame.size.width-(span*2);
CGRect dataviewframe,titleRect,buttonviewrect,imageRect;
CGSize newsize;
[cell.lblDescreption setFont:[UIFont fontWithName:FONT_LIGHT size:16]];
[cell.lblDescreption setNumberOfLines:3];
[cell.linkimage setHidden:NO];
if([AFNetworkReachabilityManager sharedManager].isReachable){
//Unspacified ImageView
if([[info objectForKey:@"copied_url_img"]isEqualToString:@"nil"]){
[cell.linkimage setHidden:YES];//hide image
//make call to get image & title of Copied URL
[self MakeCallAndSetImageToImageView:indexPath ToGetImageFromURL:[info valueForKey:@"copied_url"]];
//new size of link title
y = span+dateviewsize+span+linesize+1;
if([[info objectForKey:@"copied_url_description"] isEqualToString:@"nil"]){
[cell.lblDescreption setHidden:YES];//hide description
//set dataview's new height
h = span+dateviewsize+span;
}
else{
[cell.lblDescreption setHidden:NO];//show description
NSString* string = [NSString stringWithFormat:@"%@",[info objectForKey:@"copied_url_description"]];
[cell.lblDescreption setText:string];
newsize = [self getStringHeightWithMaxWidth:w-(span*2) AndText:cell.lblDescreption];
if(newsize.height > descriptionsize){
titleRect = CGRectMake(span,y,w-(span*2),descriptionsize);
//set dataview's new height
h = y+descriptionsize+span;
}else{
titleRect = CGRectMake(span,y,w-(span*2),newsize.height);
//set dataview's new height
h = y+newsize.height+span;
}
[cell.lblDescreption setFrame:titleRect];
}
dataviewframe = CGRectMake(span,span,w,h);
//set buttonview's new frame
buttonviewrect = CGRectMake(span,h+span+2,w,50);
}else{
[cell.linkimage setHidden:NO];//show image
//new size of link image
y = span+dateviewsize+span+linesize+1;
float imageH = [self SizeWithScaledToWidth:w-(span*2)].height;
imageRect = CGRectMake(span,y,w-(span*2),imageH);
NSString* imgurl=[NSString stringWithFormat:@"%@",[info objectForKey:@"copied_url_img"]];
[cell.linkimage setImageWithURL:[NSURL URLWithString:imgurl]];
[cell.linkimage setFrame:imageRect];
y = y+imageH+span;
//new size of link title
if([[info objectForKey:@"copied_url_description"] isEqualToString:@"nil"]){
[cell.lblDescreption setHidden:YES];
h = y+span;
}else{
[cell.lblDescreption setHidden:NO];//show description
NSString* string = [NSString stringWithFormat:@"%@",[info objectForKey:@"copied_url_description"]];
[cell.lblDescreption setText:string];
newsize = [self getStringHeightWithMaxWidth:w-(span*2) AndText:cell.lblDescreption];
if(newsize.height > descriptionsize){
titleRect = CGRectMake(span,y,w-(span*2),descriptionsize);
//set dataview's new height
h = y+descriptionsize+span;
}else{
titleRect = CGRectMake(span,y,w-(span*2),newsize.height);
//set dataview's new height
h = y+newsize.height+span;
}
[cell.lblDescreption setFrame:titleRect];
}
//set dataview's new frame
dataviewframe = CGRectMake(span,span,w,h);
//set buttonview's new frame
buttonviewrect = CGRectMake(span,h+span+2,w,50);
}
}else{
//NO INTERNET CONNECTION
//hide link image
[cell.linkimage setHidden:YES];
//hide link title
[cell.lblDescreption setHidden:YES];
//set dataview's new frame
h = span+dateviewsize;
dataviewframe = CGRectMake(span,span,w,h);
//set buttonview's new frame
buttonviewrect = CGRectMake(span,h+span+2,w,50);
}
cell.dataview.frame = dataviewframe;
cell.buttonview.frame = buttonviewrect;
if([selectedRow isEqual:indexPath]){
cell.buttonview.alpha=1;
}else{
cell.buttonview.alpha=0;
}
[cell.btnShare setHidden:NO];
[cell.buttonview bringSubviewToFront:cell.btnShare];
[cell.buttonview bringSubviewToFront:cell.btnOpen];
[cell.buttonview bringSubviewToFront:cell.btnCopy];
[cell.buttonview bringSubviewToFront:cell.btnDelete];
[cell.btnShare addTarget:self action:@selector(Action:) forControlEvents:UIControlEventTouchUpInside];
[cell.btnOpen addTarget:self action:@selector(Action:) forControlEvents:UIControlEventTouchUpInside];
[cell.btnCopy addTarget:self action:@selector(Action:) forControlEvents:UIControlEventTouchUpInside];
[cell.btnDelete addTarget:self action:@selector(Action:) forControlEvents:UIControlEventTouchUpInside];
[cell.btnShare setTag:indexPath.row];
[cell.btnOpen setTag:indexPath.row];
[cell.btnCopy setTag:indexPath.row];
[cell.btnDelete setTag:indexPath.row];
return cell;
}
这里是我的屏幕截图
在此先感谢告诉我是否需要更多信息。
答
经过很长时间，我发现我的代码中有错误。我正在设置buttonview标记indexPath.row并且还给button标记了相同的标记。当DidSelectRowAtIndexPath被调用，我在做什么，
-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
linkCell*cell = (linkCell*)[tableView cellForRowAtIndexPath:indexPath];
if([selectedRow isEqual:indexPath]){
selectedRow = nil;
//this is where i'm mistaking.
[[cell viewWithTag: indexPath.row]setAlpha:1];
}else{
selectedRow = indexPath;
//this is where i'm mistaking.
[[cell viewWithTag: indexPath.row]setAlpha:0];
}
[tableView reloadData];
}
所以，我给-1标签buttonview，问题就解决了。
if([selectedRow isEqual:indexPath]){
selectedRow = nil;
[[cell viewWithTag: -1]setAlpha:1];
}else{
selectedRow = indexPath;
[[cell viewWithTag: -1]setAlpha:0];
}
的方式感谢您宝贵提示，并建议。
答
你在-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath方法中做得太多了。给定制单元一个配置方法，比如-(void)configureCell，这个单元的内容和布局将被定义是一个很好的习惯。换句话说，让单元负责（尽可能）其内容和布局而不是tableview。
我想这个部分会导致问题：
if([AFNetworkReachabilityManager sharedManager].isReachable) {
...
}
特别：
[self MakeCallAndSetImageToImageView:indexPath ToGetImageFromURL:[info valueForKey:@"copied_url"]];
我不知道这种方法的实现，但我有你要看看那边的感觉，因为它可能是检索您请求的图像时的线程问题。
另一个提示：您命名类和方法的方式并不总是遵循Objective-C约定。检查linkCell（班级）和MakeCallAndSetImageToImageView ...（方法）。
答
可能的布局破裂。尝试捕获视图层次结构。在Xcode中：调试>查看调试>捕获视图层次结构。
此外，方法dequeueReusableCellWithIdentifier：forIndexPath：始终返回有效的单元格。如果（！cell）{...}永远不会被执行，您可以将其删除。
答
尝试使用这块GCD，我认为它会工作。
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
//Do data fetching and calculation
dispatch_async(dispatch_get_main_queue(), ^(void) {
//Update UI on main thread
});
});
删除并尝试'if（！cell）{cellCell alloc] initWithStyle：UITableViewCellStyleDefault reuseIdentifier：@“cell”]; }' –
将表格视图单元格作为自定义单元格 –