Question

在桌面视图中滚动时我的应用会冻结。它加载数据，但是当我尝试滚动时，应用程序立即冻结。问题是什么？我的cellforrowatindexpath方法是：

if (cell == nil) { 

    cell = [[[NSBundle mainBundle] loadNibNamed:@"MyCellView" owner:self options:nil]objectAtIndex:0];
}

getDats *gDatas=[[[getDats alloc]init]autorelease];

gDatas=[self.bookmarks objectAtIndex:indexPath.row];

const char *prior = "High"; 

const char *prior1 =[gDatas.Priority UTF8String]; 

if (strcmp(prior1 , prior) == 0)
 {
    NSString *imagePath = [[NSBundle mainBundle]pathForResource:@"highPriority" ofType:@"png"]; 

cell.imageView.image = [UIImage imageWithContentsOfFile:imagePath];   
}

[cell.MOwner setText:gDatas.WhatId];

[cell.DueDate setText:gDatas.EndDateTime];

[cell.theTextLabel setText:gDatas.Subject];

[cell.Descri setText:gDatas.Desc];

[cell.TaskId setText:[NSString stringWithFormat:@"%d" , gDatas.rowId]];  

cell.backgroundView.backgroundColor = [UIColor scrollViewTexturedBackgroundColor];

return cell;

，调试器显示：

- [__ NSCFString Priority]：无法识别的选择器发送到实例0x7341790 2012-07-09 10：23：46.761 MeetingMaker [716：207] *由于未捕获的异常'NSInvalidArgumentException'终止应用程序，原因：' - [__ NSCFString Priority]：无法识别的选择器发送到实例0x7341790' * 第一次抛出调用堆栈：（0x1cbf052 0x2152d0a 0x1cc0ced 0x1c25f00 0x1c25ce2 0xf449 0x4e7e0f 0x4e8589 0x4d3dfd 0x4e2851 0x48d301 0x1cc0e72 0x29492d 0x29e827 0x224fa7 0x226ea6 0x2c037a 0x2c01af 0x1c93966 0x1c93407 0x1bf67c0 0x1bf5db4 0x1bf5ccb 0x2656879 0x265693e 0x44ea9b 0xe0c2 0x1e15）终止调用抛出异常（gdb）。

该应用在线显示错误：

const char *prior1 =[gDatas.Priority UTF8String];

并显示

线程：程序接收信号SIGABRT。

Answer 1

你需要重用你的单元格，当你向下滚动一个UITableView时，不再在视图中的单元格被重用，因为你需要为单元格设置一个resuseIdentifier。

来自UITableViewCell docs

reuseIdentifier
A string used to identify a cell that is reusable. (read-only)

@property(nonatomic, readonly, copy) NSString *reuseIdentifier
Discussion
The reuse identifier is associated with a UITableViewCell object that the table-view’s delegate creates with the intent to reuse it as the basis (for performance reasons) for multiple rows of a table view. It is assigned to the cell object in initWithFrame:reuseIdentifier: and cannot be changed thereafter. A UITableView object maintains a queue (or list) of the currently reusable cells, each with its own reuse identifier, and makes them available to the delegate in the dequeueReusableCellWithIdentifier: method.

因此，你应该用这样的方法开始你的方法：

static NSString *CellIdentifier = @"Cell";  
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
 if (cell == nil) {      
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];

}

在tableview中滚动时应用冻结

1 个答案: