UIColor *bgColor = [[UIColor alloc] initWithWhite:1 alpha:0.0];
historyTable.backgroundColor = bgColor;

UIColor *bgColor = [[UIColor alloc] initWithWhite:1 alpha:0.0];
historyTable.backgroundColor = bgColor;

historyTable.backgroundColor = [UIColor clearColor];

xxx.backgroundView = nil;

if ([self.tableView respondsToSelector:@selector(setBackgroundView:)]) {
    [self.tableView setBackgroundView:nil];
}

[myTableView setBackgroundView:nil];
[myTableView setBackgroundColor:[UIColor clearColor]];

[[UIColor alloc] initWithWhite:1 alpha:0.0];

[UIColor clearColor];

cell.backgroundColor =  [UIColor clearColor];