性能核心图

Question

I have tabbar with 2 inset. In first inset i have image on which 8 labels with some values. I wrote method thath remove first object from an array and add random object to end of array. I use this method for add values for labels. Every 2 seconds it updates.

-(void) imageBackground
{
    labValues1.text = [[[CPDConstants sharedInstance].arr lastObject] stringValue];
    labValues2.text = [[[CPDConstants sharedInstance].arr2 lastObject] stringValue];
    labValues3.text = @"9.76";
    labValues4.text = @"9.81";
    labValues5.text = [[[CPDConstants sharedInstance].arr3 lastObject] stringValue];
    labValues6.text = [[[CPDConstants sharedInstance].arr4 lastObject] stringValue];
    labValues7.text = @"10.01";
    labValues8.text = @"10.03";

   [NSTimer scheduledTimerWithTimeInterval:2.0f
                                     target:self
                                   selector:@selector(imageBackground)
                                   userInfo:nil
                                    repeats:YES];
}

In viewDidLoad i create array [CPDConstants sharedInstance].arr with some start values and use timer for updating the values

  [NSTimer scheduledTimerWithTimeInterval:2 target:self selector:@selector(generator) userInfo:nil repeats:YES];

-(void)generator
{
    [[CPDConstants sharedInstance].arr removeObjectAtIndex:0];
    NSInteger countKiss=arc4random()%30;
    [[CPDConstants sharedInstance].arr addObject:[NSNumber numberWithInteger:(20+countKiss)]];
}

In second inset i have 4 plot. I devide the screen on 4 view and add the graphs. and call

[graph reloadData];
[graph2 reloadData];
[graph3 reloadData];
[graph4 reloadData];

And it's work. But it's very slow. I make it for creating real-time plot with dynamic data.

How can I make it faster? I think the main problem is in updating labels. If my program work more than 10-15 sec it becomes very slow and i can change inset, it doesn't responds.

Answer 1

See the "Real Time Plot" demo in the Plot Gallery example app for one approach. Instead of loading all of the plot data and labels on every update, tell the plots to update only the points that change. Use -insertDataAtIndex:numberOfRecords: to insert the new data points and -deleteDataInIndexRange: to remove any old data that you no longer need.