Ios 如何从单元格中删除以前的内容

我有带搜索栏的tableview。我正在显示单元格中的数据数。我正在使用xib创建细胞。我还在单元格中添加了两个按钮。现在，当我在搜索栏中搜索任何东西时，时间表正在重新加载，单元格按钮再次添加到该位置。 请参见以下屏幕截图： 1） 第一次创建tableview：

2） 搜索后数据：

![enter image description here][2]

我的代码：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
WorkDetailCell *cell = [tableView dequeueReusableCellWithIdentifier:@"WorkDetailCell"];
if (cell == nil) {
    NSArray *topLevelObject;
    topLevelObject = [[NSBundle mainBundle] loadNibNamed:@"WorkDetailCell" owner:self options:nil];
    cell = [topLevelObject objectAtIndex:0];
    cell.backgroundColor=RGB(210, 200, 191);
    cell.selectedBackgroundView=[self selectedCellView];
}

if(search==FALSE){
    NSLog(@"%d",indexPath.row);
    cell.clearsContextBeforeDrawing=YES;
    //NSDictionary *detailList=[tempDataArray objectAtIndex:indexPath.row];
    NSArray *temp=[tempDataArray objectAtIndex:indexPath.row];
    cell.lblOrganization.text=[temp objectAtIndex:1];//@"TGB";//[detailList valueForKey:@"organizationName"];
    cell.lblAddress.text=[temp objectAtIndex:2];//@"Ahmedabad";//detailList[@"address"];
    cell.lblLandmark.text=[temp objectAtIndex:3];//@"SG HighWay";//detailList[@"landmark"];
    cell.lblCity.text=[temp objectAtIndex:4];//@"Ahmedabad";//detailList[@"city"];
    cell.lblState.text=[temp objectAtIndex:5];//@"Ahmedabad";//detailList[@"state"];


    UIButton *doneButton=[UIButton buttonWithType:UIButtonTypeCustom];
    doneButton.frame=CGRectMake(220, 45, 100, 60);
  //[doneButton setTitle:@"pick" forState:UIControlStateNormal];
    [doneButton addTarget:self action:@selector(doneButtonClicked:) fo rControlEvents:UIControlEventTouchUpInside];
   [doneButton setImage:[UIImage imageNamed:@"pick"] forState:UIControlStateNormal];
    [doneButton setTag:indexPath.row];
   UIButton *previewButton=[UIButton buttonWithType:UIButtonTypeCustom];
    previewButton.frame=CGRectMake(235, 15, 65, 30);
    [previewButton setTitle:@"Preview" forState:UIControlStateNormal];
    [previewButton setTitleColor:RGB(110, 73, 44) forState:UIControlStateNormal];
    [previewButton addTarget:self action:@selector(previewButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
    [previewButton setTag:indexPath.row];
    [cell.contentView addSubview:doneButton];
    [cell.contentView addSubview:previewButton];
}
else{
 //   NSDictionary *detailList=[searchResultArray objectAtIndex:indexPath.row];
   // NSLog(@"dic%@",detailList);
    //cell.contentView.clearsContextBeforeDrawing=YES;
  cell.clearsContextBeforeDrawing=YES;
    NSArray *temp=[searchResultArray objectAtIndex:indexPath.row];
    cell.lblOrganization.text= [temp objectAtIndex:1]; //[detailList valueForKey:@"organizationName"];
    cell.lblAddress.text=[temp objectAtIndex:2];//detailList[@"address"];
    cell.lblLandmark.text=[temp objectAtIndex:3];//detailList[@"landmark"];
    cell.lblCity.text=[temp objectAtIndex:4];//detailList[@"city"];
    cell.lblState.text=[temp objectAtIndex:5];//detailList[@"state"];
    UIButton *doneButton=[UIButton buttonWithType:UIButtonTypeCustom];
    doneButton.frame=CGRectMake(220, 45, 100, 60);
  //[doneButton setTitle:@"pick" forState:UIControlStateNormal];
    [doneButton addTarget:self action:@selector(doneButtonClicked:) fo rControlEvents:UIControlEventTouchUpInside];
   [doneButton setImage:[UIImage imageNamed:@"pick"] forState:UIControlStateNormal];
    [doneButton setTag:indexPath.row];
   UIButton *previewButton=[UIButton buttonWithType:UIButtonTypeCustom];
    previewButton.frame=CGRectMake(235, 15, 65, 30);
    [previewButton setTitle:@"Preview" forState:UIControlStateNormal];
    [previewButton setTitleColor:RGB(110, 73, 44) forState:UIControlStateNormal];
    [previewButton addTarget:self action:@selector(previewButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
    [previewButton setTag:indexPath.row];
    [cell.contentView addSubview:doneButton];
    [cell.contentView addSubview:previewButton];
   }
   return cell;

---

您必须使用

nil

值来删除或插入可重复代码以实现可重用性

if

（这是：

if（cell==nil）{

这里的主要规则是创建一个单元格，您必须将两种对象分开： -每个单元格特有的对象（文本除外） -重复对象（主要是样式对象，如颜色、背景、阴影、按钮等）

第一组应该在可重用性“if”（cell==nil）之外。第二组应该在内部

就你而言：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
WorkDetailCell *cell = [tableView dequeueReusableCellWithIdentifier:@"WorkDetailCell"];
if (cell == nil) {
    NSArray *topLevelObject;
    topLevelObject = [[NSBundle mainBundle] loadNibNamed:@"WorkDetailCell" owner:self options:nil];
    cell = [topLevelObject objectAtIndex:0];
    cell.backgroundColor=RGB(210, 200, 191);
    cell.selectedBackgroundView=[self selectedCellView];

   UIButton *doneButton=[UIButton buttonWithType:UIButtonTypeCustom];
    doneButton.frame=CGRectMake(220, 45, 100, 60);
  //[doneButton setTitle:@"pick" forState:UIControlStateNormal];
    [doneButton addTarget:self action:@selector(doneButtonClicked:) fo rControlEvents:UIControlEventTouchUpInside];
   [doneButton setImage:[UIImage imageNamed:@"pick"] forState:UIControlStateNormal];
    [doneButton setTag:indexPath.row];
   UIButton *previewButton=[UIButton buttonWithType:UIButtonTypeCustom];
    previewButton.frame=CGRectMake(235, 15, 65, 30);
    [previewButton setTitle:@"Preview" forState:UIControlStateNormal];
    [previewButton setTitleColor:RGB(110, 73, 44) forState:UIControlStateNormal];
    [previewButton addTarget:self action:@selector(previewButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
    [cell.contentView addSubview:doneButton];
    [cell.contentView addSubview:previewButton];
}

if(search==FALSE){
    NSLog(@"%d",indexPath.row);
    cell.clearsContextBeforeDrawing=YES;
    //NSDictionary *detailList=[tempDataArray objectAtIndex:indexPath.row];
    NSArray *temp=[tempDataArray objectAtIndex:indexPath.row];
    cell.lblOrganization.text=[temp objectAtIndex:1];//@"TGB";//[detailList valueForKey:@"organizationName"];
    cell.lblAddress.text=[temp objectAtIndex:2];//@"Ahmedabad";//detailList[@"address"];
    cell.lblLandmark.text=[temp objectAtIndex:3];//@"SG HighWay";//detailList[@"landmark"];
    cell.lblCity.text=[temp objectAtIndex:4];//@"Ahmedabad";//detailList[@"city"];
    cell.lblState.text=[temp objectAtIndex:5];//@"Ahmedabad";//detailList[@"state"];


    [previewButton setTag:indexPath.row];

}
else{
 //   NSDictionary *detailList=[searchResultArray objectAtIndex:indexPath.row];
   // NSLog(@"dic%@",detailList);
    //cell.contentView.clearsContextBeforeDrawing=YES;
  cell.clearsContextBeforeDrawing=YES;
    NSArray *temp=[searchResultArray objectAtIndex:indexPath.row];
    cell.lblOrganization.text= [temp objectAtIndex:1]; //[detailList valueForKey:@"organizationName"];
    cell.lblAddress.text=[temp objectAtIndex:2];//detailList[@"address"];
    cell.lblLandmark.text=[temp objectAtIndex:3];//detailList[@"landmark"];
    cell.lblCity.text=[temp objectAtIndex:4];//detailList[@"city"];
    cell.lblState.text=[temp objectAtIndex:5];//detailList[@"state"];

    [previewButton setTag:indexPath.row];
   }
   return cell;

---

重新加载tableview时，需要删除作为子视图添加的按钮 因此，在您的

-（UITableViewCell*）表视图中：（UITableView*）表视图cellforrowatinexpath:（nsindepath*）indepath{

只需调用

[cell.contentView removeSubViews]；

---

这应该会有所帮助，代码中有两个问题：

您为

doneButton

和

previewButton

设置了标记，但该标记从未被使用过。那么该标记的用途是什么

当您滚动表格视图时，表格视图单元格将被重新使用。例如，如果在索引0处显示的单元格在索引10处被重新使用，则作为您的代码，按钮将再次添加

因此，您可以为所有按钮分别设置一个唯一的标记，并且每次调用

-（UITableViewCell*）tableView:（UITableView*）tableView cellforrowatinexpath:（nsindepath*）indepath

，您都应该检查按钮是否已添加，如果已添加，则应避免再次添加按钮

您可以添加如下代码：

    if (![cell viewWithTag:YOUR_BUTTON_TAG]) {
        //create and add your button
    }

---

他不需要可重用性，如果你明白这不是可重用性的问题，他每次都在添加内容，这样你就可以删除不需要的内容，这样按钮就不会像图片中那样被添加两次。每个人都需要可重用性！如果你每次设置单元格的样式，滚动会出现可怕的滞后。更改文本每次都是肯定的，重画按钮-不！好的，我想要完全一样的东西…谢谢…我明白你的意思了