Why I can't draw in a loop? (Using UIView in iPhone)
- by Tattat
I can draw many things using this :
NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"dummy2.png" ofType:nil];
UIImage *img = [UIImage imageWithContentsOfFile:imagePath];
image = CGImageRetain(img.CGImage);
CGRect imageRect;
double x = 0;
double y = 0;
for (int k=0; k<someValue; k++) {
x += k;
y += k;
imageRect.origin = CGPointMake(x, y);
imageRect.size = CGSizeMake(25, 25);
CGContextDrawImage(UIGraphicsGetCurrentContext(), imageRect, image);
}
}
CGImageRelease(img.CGImage);
So, it works, so, I put it into a command object's execute method. Then, I want to do similar thing, but this time, my execute method only do this:
NSString *imagePath = [[NSBundle mainBundle] pathForResource:@"dummy2.png" ofType:nil];
UIImage *img = [UIImage imageWithContentsOfFile:imagePath];
image = CGImageRetain(img.CGImage);
CGRect imageRect;
double x = inComingX;
double y = inComingY;
imageRect.origin = CGPointMake(x, y);
imageRect.size = CGSizeMake(25, 25);
CGContextDrawImage(UIGraphicsGetCurrentContext(), imageRect, image);
CGImageRelease(img.CGImage);
This time, this is also a Command, and it is the execute method. But I take the for loop away. I will have another method that pass the inComingX , and inComingY into my Command object.
My Drawing method is simply execute the Cmd that passed in my drawingEngine:
-(void)drawInContext:(CGContextRef)context
{
[self.cmdToBeExecuted execute];
}
I also have the assign method to assign the command,:
-(void)assignCmd:(Command* )cmd{
self.cmdToBeExecuted = cmd;
}
And this is the way I called the drawingEngine
for(int k=0; k<5; k++){
[self.drawingEngine assignCmd:[DrawingCmd setDrawingInformation:(10*k):0:@"dummy.png"]];
[self.drawingEngine setNeedsDisplay];
}
It can draw, but the sad thing is it only draw the last one. Why? and how to fix it? I can draw all the things in my First code, but after I take the loop outside, and use the loop in last code, it just only draw the last one. Plz help
