UITableView 滚动出现问题了，帮忙找找原因

这是什么原因呢？
-(id)initWithTextFild:(UITextField *)_txtFild

{

self=[super init]; 

if(self){ 

    txtFild=_txtFild; 

// [txtFild resignFirstResponder];

} 

return self; 

}
-(void)viewDidLoad

{

[super viewDidLoad]; 

//初始化tableview的数据 

self.tableView.separatorStyle = UITableViewCellSeparatorStyleNone; 

[self refreshData:[self->txtFild text]]; 

}

-(void) refreshData:(NSString *) text

{

datalist = nil; 

datalist = [[NSMutableArray alloc] init];     

NSRange range=[text rangeOfString:@"@"]; 

prefix=[text substringToIndex:range.location]; 

suffixPrefix=[text substringFromIndex:range.location]; 

NSString * suffixStr=[NSStringlocalizedStringWithFormat:ILEAD_STRING_EMAIL_SUFFIX,@"email suffix"];

NSArray * suffixList=[suffixStr componentsSeparatedByString:@";"]; 

for (NSString * suffix in suffixList) { 

    if([suffix hasPrefix:suffixPrefix]){ 

        [datalist addObject:[NSString stringWithFormat:@"%@%@",prefix,suffix]]; 

    } 

} 

float hg =81; 

if([datalist count]<3){ 

    hg=[datalist count]*27; 

} 

float x=txtFild.frame.origin.x; 

float y=txtFild.frame.origin.y; 

float width=txtFild.frame.size.width; 

float height=txtFild.frame.size.height; 

[self.view setFrame:CGRectMake(x+2, y+height+8, width-4, hg)]; 

}
-(NSInteger) numberOfSectionsInTableView:(UITableView *)tableView
{

return 1; 

}

• (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
  {

if ([datalist count]>0) 

{ 

    tableView.separatorStyle=UITableViewCellSeparatorStyleSingleLine; 

} 

return [datalist count]; 

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

{

NSString *cellWithIdentifier = [NSString stringWithFormat:@"Cell%d", indexPath.row];//这里按照每个row来标 

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellWithIdentifier]; 

if(cell == nil) 

{ 

    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellWithIdentifier]; 

} 

NSUInteger row  = [indexPath row]; 

cell.textLabel.text = [datalist objectAtIndex:row]; 

cell.textLabel.font = [UIFont fontWithName:@"Helvetica" size:16]; 

return cell; 

}

//设置内容缩进

• (NSInteger)tableView:(UITableView )tableView indentationLevelForRowAtIndexPath:(NSIndexPath )indexPath
  {

return 0;

}
//设置cell的行高

• (CGFloat)tableView:(UITableView )tableView heightForRowAtIndexPath:(NSIndexPath )indexPath

{
return 27;

}
//当选择指定的cell时，显示选择的内容

• (void)tableView:(UITableView )tableView didSelectRowAtIndexPath:(NSIndexPath )indexPath

{

txtFild.text = [[NSString alloc] initWithFormat:@"%@",[datalist objectAtIndex:[indexPath row]]]; 
  [self.view removeFromSuperview]; 

}
-(BOOL) tableView:(UITableView )tableView canEditRowAtIndexPath:(NSIndexPath )indexPath

{

return NO; 

}

• (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

{ return (interfaceOrientation == UIInterfaceOrientationPortrait);

}
@end