应用程序崩溃是由于内存压力

我在这里产生UIViews的图像和我使用下面的代码：应用程序崩溃是由于内存压力

// ======================== Create PDF FROM Images  ============================ 

- (void) drawBorder 
{ 
    CGContextRef currentContext = UIGraphicsGetCurrentContext(); 
    UIColor *borderColor = [UIColor grayColor]; 

    CGRect rectFrame = CGRectMake(kBorderInset, kBorderInset, pageSize.width-kBorderInset*2, pageSize.height-kBorderInset*2); 

    CGContextSetStrokeColorWithColor(currentContext, borderColor.CGColor); 
    CGContextSetLineWidth(currentContext, kBorderWidth); 
    CGContextStrokeRect(currentContext, rectFrame); 

    //CGContextRelease(currentContext); 
} 

- (void)drawPageNumber:(NSInteger)pageNumber 
{ 
    NSString* pageNumberString = [NSString stringWithFormat:@"Page %d", pageNumber]; 
    UIFont* theFont = [UIFont systemFontOfSize:12]; 

    CGSize pageNumberStringSize = [pageNumberString sizeWithFont:theFont 
               constrainedToSize:pageSize 
                lineBreakMode:NSLineBreakByWordWrapping]; 

    CGRect stringRenderingRect = CGRectMake(kBorderInset, 
              pageSize.height - 40.0, 
              pageSize.width - 2*kBorderInset, 
              pageNumberStringSize.height); 

    [pageNumberString drawInRect:stringRenderingRect withFont:theFont lineBreakMode:NSLineBreakByWordWrapping alignment:NSTextAlignmentCenter]; 
} 

- (void) drawHeader:(int)i; 
{ 
    CGContextRef currentContext = UIGraphicsGetCurrentContext(); 
    //CGContextSetRGBFillColor(currentContext, 0.3, 0.7, 0.2, 1.0); 

    CGContextSetRGBFillColor(currentContext, 0.0f, 0.0f, 0.0f, 1); 

    //NSString *textToDraw = [NSString stringWithFormat:@"%@: %@ \n\nDate Range: %@ \n\nNumber of observations: %@",appDelegate.teacherName,@"Curriculum report",lblDate.text,lblNoOf.text]; 
    NSString *textToDraw; 

    if(i<[arrReportTitles count]) 
     textToDraw=[arrReportTitles objectAtIndex:i]; 

    UIFont *font = [UIFont systemFontOfSize:16.0]; 

    CGSize stringSize = [textToDraw sizeWithFont:font constrainedToSize:CGSizeMake(pageSize.width - 2*kBorderInset-2*kMarginInset, pageSize.height - 2*kBorderInset - 2*kMarginInset) lineBreakMode:NSLineBreakByWordWrapping]; 

    CGRect renderingRect = CGRectMake(kBorderInset + kMarginInset, kBorderInset + kMarginInset, pageSize.width - 2*kBorderInset - 2*kMarginInset, stringSize.height); 

    [textToDraw drawInRect:renderingRect withFont:font lineBreakMode:NSLineBreakByWordWrapping alignment:NSTextAlignmentLeft]; 

    //CGContextRelease(currentContext); 
} 

- (void) drawText 
{ 
    CGContextRef currentContext = UIGraphicsGetCurrentContext(); 
    CGContextSetRGBFillColor(currentContext, 0.0, 0.0, 0.0, 1.0); 
    NSString *textToDraw = @"TeachersEvaluation"; 
    UIFont *font = [UIFont systemFontOfSize:24.0]; 
    CGSize stringSize = [textToDraw sizeWithFont:font 
           constrainedToSize:CGSizeMake(pageSize.width - 2*kBorderInset-2*kMarginInset, pageSize.height - 2*kBorderInset - 2*kMarginInset) 
            lineBreakMode:NSLineBreakByWordWrapping]; 

    CGRect renderingRect = CGRectMake(kBorderInset + kMarginInset + 375, kBorderInset + kMarginInset + 450.0, pageSize.width - 2*kBorderInset - 2*kMarginInset, stringSize.height-50); 
    [textToDraw drawInRect:renderingRect 
        withFont:font 
      lineBreakMode:NSLineBreakByWordWrapping 
       alignment:NSTextAlignmentLeft]; 

    //CGContextRelease(currentContext); 
} 

- (void) drawLine 
{ 
    CGContextRef currentContext = UIGraphicsGetCurrentContext(); 

    CGContextSetLineWidth(currentContext, kLineWidth); 

    CGContextSetStrokeColorWithColor(currentContext, [UIColor grayColor].CGColor); 

    CGPoint startPoint = CGPointMake(kMarginInset + kBorderInset, kMarginInset + kBorderInset + 120.0); 
    CGPoint endPoint = CGPointMake(pageSize.width - 2*kMarginInset -2*kBorderInset, kMarginInset + kBorderInset + 120.0); 

    CGContextBeginPath(currentContext); 
    CGContextMoveToPoint(currentContext, startPoint.x, startPoint.y); 
    CGContextAddLineToPoint(currentContext, endPoint.x, endPoint.y); 

    CGContextClosePath(currentContext); 
    CGContextDrawPath(currentContext, kCGPathFillStroke); 

    //CGContextRelease(currentContext); 
} 

-(NSInteger) getImageHeighAndWidht : (NSInteger) value 
{ 
    value = value/2; 

    if (value > 800) { 

     [self getImageHeighAndWidht:value]; 

    } 

    if (value<450) { 

     value = value + (value/2); 

    } 

    return value; 
} 

- (void) drawImage: (UIImage *)fileName 
{ 
    CGSize mainImageSize; 
    UIImage *mainImage; 

    if (fileName.size.width > 542 || fileName.size.height > 742) 
    { 
     if (fileName.size.height > fileName.size.width) { 

      mainImageSize = CGSizeMake(470,575); 
      mainImage =fileName; //[fileName scaleProportionalToSize:mainImageSize]; 

     } else { 

      mainImageSize = CGSizeMake(290,395); 
      mainImage = fileName;//[fileName scaleProportionalToSize:mainImageSize]; 

     } 

    } else { 

     mainImageSize = CGSizeMake(fileName.size.width,fileName.size.height); 
     mainImage =fileName; //[fileName scaleProportionalToSize:mainImageSize]; 
    } 

    float imageWidht; 
    if (mainImage.size.width > 542) 
    { 
     imageWidht = 542; 
    } else { 
     imageWidht = mainImage.size.width; 
    } 

    float imageHeight; 
    if (mainImage.size.height > 575) 
    { 
     imageHeight = 600.0; 
    } else { 
     imageHeight = mainImage.size.height; 
    } 

    //UIImage * demoImage = [UIImage imageNamed:fileName]; 
    [mainImage drawInRect:CGRectMake((pageSize.width - imageWidht)/2, 150, imageWidht, imageHeight)]; 
} 

- (void) generatePdfWithFilePath: (NSString *)thefilePath 
{ 
    UIGraphicsBeginPDFContextToFile(thefilePath, CGRectZero, nil); 

    NSInteger currentPage = 0; 

// _imgViewScreenShot.image=[arrMultiplePhots objectAtIndex:0]; 
// _imgViewScreenShot2.image=[arrMultiplePhots objectAtIndex:1]; 


    for(int i = 0; i < [arrMultiplePhots count]; i++){ 

     //Start a new page. 
     UIGraphicsBeginPDFPageWithInfo(CGRectMake(0, 0, pageSize.width, pageSize.height), nil); 

     //Draw a page number at the bottom of each page. 
     currentPage++; 
     [self drawPageNumber:currentPage]; 

     //Draw a border for each page. 
     [self drawBorder]; 

     //Draw text fo our header. 
     [self drawHeader:i]; 

     //Draw a line below the header. 
     [self drawLine]; 

     //if(i == 0) { 
     //currImage = [self.view imageByRenderingView]; 

     //_imgViewScreenShot.image=currImage; 
     [self drawImage:[arrMultiplePhots objectAtIndex:i]]; 
     //} 
    } 

    // Close the PDF context and write the contents out. 
    UIGraphicsEndPDFContext(); 
}

但是，当我生成一个不断循环中的多个视图，我的应用程序崩溃与图片警告“应用程序因内存压力而崩溃”。

我用仪器工具找出了这次事故的原因，并发现了所有这些功能的内存泄漏警告。

那么如何在上面的代码中解决这个内存泄漏问题呢？

编辑

使用自动释放内存泄漏后，上述功能

现在我得到的内存泄漏此功能被删除

其生成图像

- (UIImage *)imageByRenderingView 
{ 
    UIGraphicsBeginImageContext(self.bounds.size); 
    [self.layer renderInContext:UIGraphicsGetCurrentContext()]; 
    UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext(); 
    UIGraphicsEndImageContext(); 
    return resultingImage; 
}

来源

2014-01-22 ViruMax

试试这个变化，告诉我它是否有帮助：

- (void) generatePdfWithFilePath: (NSString *)thefilePath 
{ 
    UIGraphicsBeginPDFContextToFile(thefilePath, CGRectZero, nil); 

    NSInteger currentPage = 0; 

// _imgViewScreenShot.image=[arrMultiplePhots objectAtIndex:0]; 
// _imgViewScreenShot2.image=[arrMultiplePhots objectAtIndex:1]; 


    for(int i = 0; i < [arrMultiplePhots count]; i++) 
    { 
     @autoreleasepool { 
      //Start a new page. 
      UIGraphicsBeginPDFPageWithInfo(CGRectMake(0, 0, pageSize.width, pageSize.height), nil); 

      //Draw a page number at the bottom of each page. 
      currentPage++; 
      [self drawPageNumber:currentPage]; 

      //Draw a border for each page. 
      [self drawBorder]; 

      //Draw text fo our header. 
      [self drawHeader:i]; 

      //Draw a line below the header. 
      [self drawLine]; 

      //if(i == 0) { 
      //currImage = [self.view imageByRenderingView]; 

      //_imgViewScreenShot.image=currImage; 
      [self drawImage:[arrMultiplePhots objectAtIndex:i]]; 
      //} 
     } 
    } 

    // Close the PDF context and write the contents out. 
    UIGraphicsEndPDFContext(); 
}

来源

2014-01-22 14:34:30 arturgrigor

嘿对不起，迟到的答复，并感谢您的帮助。在使用autorelease之后，内存泄漏在上述函数中被删除。但是现在我得到了一个新函数中的内存泄漏，这是我在EDIT标记下的问题中添加的。 – ViruMax

那么，你也应该用“@autoreleasepool”来打电话给那个方法。 – arturgrigor

应用程序崩溃是由于内存压力

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