CODEWITHSUNDEEP
iosipad
Christina Watson
Christina Watson

Reputation: 13

setNeedsDisplay in a UIView subclass (in an ipad Splitview) not calling drawRect

My Question is about the setNeedsDisplay method which is in my UIView sub class which doesn't call the drawRect in the same class.

I'm developing an Ipad application to show a X Y Graph (cartesian plane) where a user can enter coordinates for points. (ex: 2,4 and 2,8: this should draw a straight vertical line). I used a Master-Detail Application (so a split view controller).

1) Initially the drawRect in the UIView subclass draw the initial grid. I need to add the lines on the fly to the grid, when user adding the new points (x, y values)

2) And then after entering the x and y values (in the MasterViewController), I'm calling the point update method in UIView subclass (gridview) like the following:

- (void) updateGrid
{
    // this is a mutable array of newly created points
    self.gridview.pointList = self.pointList; 
    [self.gridview redrawGrid];
}

3) I have the setNeedsDisplay in the method, "redrawGrid" in the UIView subclass (gridview) to call the drawRect in order to redraw the grid with new data points.

Upvotes: 1

Views: 288

Answers (1)

Sulthan
Sulthan

Reputation: 130102

My guess is that you have a problem inside the drawRect:. Put a breakpoint inside the drawRect: method and you should see very fast what's going on.

Also make sure that setNeedsDisplay is really called.

Upvotes: 1

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