core text view memory leak

问题

I have created a core text view and visually it's working great but i run it for 30 minutes with a lot of data coming in and it crashes. The debugger starts saying 'received memory warning'. I think the views i'm drawing that refresh on every new line that comes in from telnet, are not leaving memory on a redraw completely. code below. The first part of this code might be an issue. I found on a redraw i had to clear the old views or it over layed or drew on top and text got garbled. But it could be any of my variables that i create that are becoming persistent.

- (void)buildFrames
{

    for (UIView __strong *view in self.subviews) {
        [view removeFromSuperview];
        view = nil;
    }



    frameXOffset = 20; //1
    frameYOffset = 0;
    double height=0;
    double oldHeight = 0;
    int columnIndex = 0;
    self.frames=nil;
    self.frames = [NSMutableArray array];
    // self.pagingEnabled = YES;
    self.delegate = self;
    CGRect textFrame = CGRectInset(self.bounds, frameXOffset, frameYOffset);
    // set string
    int spot =0;
    if(self.chatLog != nil && self.chatLog != NULL)
      if(self.chatLog.total > 300)
          spot = self.chatLog.total - 300;
    if(spot < 0)
        spot=0; // double check for thread saftey;
    int _total = self.chatLog.total;
    if(_total < 0 || _total > self.chatLog.max)
        return;

    if(self.chatLog != nil && self.chatLog != NULL)
        for(int index = spot; index < _total; index ++)
        {

            NSString *theTell = [self.chatLog getChatAt:index];
             NSString *chatType = [self.chatLog getTypeAt:index];

            if(theTell == nil || theTell == NULL)
            {    theTell=@"nil";

                 chatType = @"line";
            }
        attString=nil;
        attString = [[NSMutableAttributedString alloc] initWithString:theTell];



            //else
    //    attString = [[NSAttributedString alloc] initWithString:@"Hello core text world"];

    CTFontRef font = CTFontCreateWithName(CFSTR("Courier"), self.fontSize, NULL);
    CFAttributedStringSetAttribute((__bridge CFMutableAttributedStringRef)(attString), CFRangeMake(0, CFAttributedStringGetLength((__bridge CFAttributedStringRef)(attString))), kCTFontAttributeName, font);
if([chatType isEqual: @"line"])
{
CFAttributedStringSetAttribute((__bridge CFMutableAttributedStringRef)(attString), CFRangeMake(0, CFAttributedStringGetLength((__bridge CFAttributedStringRef)(attString))), kCTForegroundColorAttributeName, _lineColor);    

}
else if([chatType isEqual: @"notify"])
{
CFAttributedStringSetAttribute((__bridge CFMutableAttributedStringRef)(attString), CFRangeMake(0, CFAttributedStringGetLength((__bridge CFAttributedStringRef)(attString))), kCTForegroundColorAttributeName, _notifyColor);
}
else if([chatType isEqual: @"tell"])
{
    CFAttributedStringSetAttribute((__bridge CFMutableAttributedStringRef)(attString), CFRangeMake(0, CFAttributedStringGetLength((__bridge CFAttributedStringRef)(attString))), kCTForegroundColorAttributeName, _tellColor);
}
else
{
CFAttributedStringSetAttribute((__bridge CFMutableAttributedStringRef)(attString), CFRangeMake(0, CFAttributedStringGetLength((__bridge CFAttributedStringRef)(attString))), kCTForegroundColorAttributeName, _defaultColor);        
}

    textFrame =  CGRectMake(0, 0, self.bounds.size.width, self.fontSize+4);
    CGMutablePathRef path = CGPathCreateMutable(); //2
       CGPathAddRect(path, NULL, textFrame );

    CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((__bridge CFAttributedStringRef)attString);
    int textPos = 0; //3

    while (textPos < [attString length]) { //4


    //  CGPoint colOffset = CGPointMake( (columnIndex+1)*frameXOffset + columnIndex*(textFrame.size.width), 20 );
        CGPoint colOffset = CGPointMake(  20, (columnIndex+1)*frameYOffset + columnIndex*(textFrame.size.height) );
        CGRect colRect = CGRectMake(0, 0 , textFrame.size.width-10, textFrame.size.height);// was -40

        CGMutablePathRef path = CGPathCreateMutable();
        CGPathAddRect(path, NULL, colRect);

        //use the column path
        CTFrameRef frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(textPos, 0), path, NULL);
        CFRange frameRange = CTFrameGetVisibleStringRange(frame); //get visiblestringrange
        //create an empty column view
        CTColumnView *content = [[CTColumnView alloc] initWithFrame: CGRectMake(0, 0, self.contentSize.width, self.contentSize.height)];
        content.backgroundColor = [UIColor clearColor];
        content.frame = CGRectMake(colOffset.x, colOffset.y, colRect.size.width, colRect.size.height) ;

        //set the column view contents and add it as subview
        [content setCTFrame:(__bridge id)frame];  //6
        [self.frames addObject: (__bridge id)frame];
        [self addSubview: content];

        //prepare for next frame
        textPos += frameRange.length;

        //CFRelease(frame);
        CFRelease(path);

        columnIndex++;
        oldHeight = height;
        height= [self measureFrameHeight:frame];

    }
        }// end while
    //set the total width of the scroll view
    int totalPages = (columnIndex) ; //7
   // self.contentSize = CGSizeMake(totalPages*self.bounds.size.width, textFrame.size.height);


    self.contentSize = CGSizeMake(textFrame.size.width, (textFrame.size.height ) * (totalPages -1) + height + 40 );

   [self scrollRectToVisible:CGRectMake(0, 0 , textFrame.size.width-10,  (textFrame.size.height) * (totalPages -1) + height +40 ) animated: FALSE];



}

the class definition is:

@interface ConsoleView :UIScrollView<UIScrollViewDelegate>
{
    float frameXOffset;
    float frameYOffset;

    NSMutableArray *frames;

}
@property  (strong, nonatomic) NSAttributedString *attString;
-(void) addNewText:(NSString *) text;
@property (weak, nonatomic) NSMutableArray *frames;// was reatin not strong
- (void)buildFrames;
@property (strong, nonatomic) ChatTextQueue *chatLog;
@property (nonatomic) int fontSize;
@property  (strong, nonatomic) UIColor *userColor;
@property (nonatomic) CGColorRef notifyColor;
@property (nonatomic) CGColorRef lineColor;
@property (nonatomic) CGColorRef defaultColor;
@property (nonatomic) CGColorRef tellColor;

@end

回答1:

you are not releasing some objects, for example font, framesetter and frame. Use the Analyze command in xCode to find all memory leaks in your buildFrames method.

来源：https://stackoverflow.com/questions/14921476/core-text-view-memory-leak