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我正在从 imagePickerController 中挑选图像并将其调整为 80X80 并显示在表格中。

下面是 cellForRowAtIndexPath 的代码 

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil)
    {
        cell = [[UITableViewCell alloc]

                initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];

        cell.selectionStyle = UITableViewCellSelectionStyleNone;
      }

     photobj= [appD.array1 objectAtIndex:indexPath.row];
    NSLog(@"photoobj=%@",photobj);
    cell.imageView.frame=CGRectMake(0, 0, 80,80);
    cell.imageView.tag=2000+indexPath.row;

    UIImage *img1=[[[UIImage alloc]initWithData:photobj.imgdata]autorelease];
    NSLog(@"frame=%f",img1.size.width);
   // img1=[UIImage imageWithData:photobj.imgdata];
    cell.imageView.image=img1;
    NSLog(@"frame=%@",cell.imageView.image);

    return cell;//after this , crash
}

返回单元格后，如果我调用下面的图像调整大小方法，它会崩溃 

- (UIImage *)resizeImageToSize:(CGSize)targetSize withImage:(UIImage *)img
{
    UIImage *sourceImage = img;

    UIImage *newImage = [[UIImage alloc]init];

    CGSize imageSize = sourceImage.size;
    CGFloat width = imageSize.width;
    CGFloat height = imageSize.height;

    CGFloat targetWidth = targetSize.width;
    CGFloat targetHeight = targetSize.height;

    CGFloat scaleFactor = 0.0;
    CGFloat scaledWidth = targetWidth;
    CGFloat scaledHeight = targetHeight;

    CGPoint thumbnailPoint = CGPointMake(0.0,0.0);

    if (CGSizeEqualToSize(imageSize, targetSize) == NO) {

        CGFloat widthFactor = targetWidth / width;
        CGFloat heightFactor = targetHeight / height;

        if (widthFactor < heightFactor)
            scaleFactor = widthFactor;
        else
            scaleFactor = heightFactor;

        scaledWidth  = width * scaleFactor;
        scaledHeight = height * scaleFactor;

        // make image center aligned
        if (widthFactor < heightFactor)
        {
            thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
        }
        else if (widthFactor > heightFactor)
        {
            thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
        }
    }

    UIGraphicsBeginImageContext(targetSize);
    CGRect thumbnailRect = CGRectZero;
   thumbnailRect.origin = thumbnailPoint;
    thumbnailRect.size.width  = scaledWidth;
    thumbnailRect.size.height = scaledHeight;

    [sourceImage drawInRect:thumbnailRect];
    newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    if(newImage == nil)
        NSLog(@"could not scale image");

    return newImage ;
}

下面是我在上面调用方法 UIImage *imageEdited = [info objectForKey:UIImagePickerControllerOriginalImage];

self.img_imageView2.image=[self resizeImageToSize:CGSizeMake(80, 80) withImage:imageEdited   ]; 
    photobj=[[PhotoObject alloc]init];

    photobj.imgdata=UIImageJPEGRepresentation(self.img_imageView2.image, 0.9);
    [appD.array1 addObject:photobj];

如果我绕过这个 imageresizing 方法然后它工作正常，我没有得到究竟是什么问题？

4

1 回答 1

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我将首先创建一个 UIImageView 并将其添加到单元格而不是使用 cell.imageView 我还将在 if 语句中设置它并使用 else 语句从标记中调用它。否则每次出现在视图中时都会重新创建它。

尝试

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

static NSString *CellIdentifier = @"Cell";
UIImageView *myImageView;

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil)
{
    cell = [[UITableViewCell alloc]

            initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];

    cell.selectionStyle = UITableViewCellSelectionStyleNone;

    myImageView = [[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 80, 80)] autorelease];
    myImageView.tag = 2000+indexPath.row;
   [cell.contentView addSubview:myImageView];

  }
  else
  {
       myImageView = (UIImageView*)[cell.contentView viewWithTag:2000+indexPath.row];
  }

 photobj= [appD.array1 objectAtIndex:indexPath.row];
NSLog(@"photoobj=%@",photobj);


UIImage *img1=[[[UIImage alloc]initWithData:photobj.imgdata]autorelease];
NSLog(@"frame=%f",img1.size.width);

myImageView.image = img1;



  NSLog(@"frame=%@", imageView.image);

return cell;
}

我使用以下代码调整图像大小。您只需要稍微调整一下即可获取您的尺寸参数并进行缩放

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)img editingInfo:(NSDictionary *)editInfo {
image.image = img;



[self _resizeImage];

[picker dismissModalViewControllerAnimated:YES];




}



//function that is called by the image picker to resize the image for passing from one view to the next
- (void) _resizeImage {
NSInteger height;
NSInteger width;
height = 280;
width = 280;

CGImageRef imageRef = [image.image CGImage];
CGImageAlphaInfo alphaInfo = CGImageGetAlphaInfo(imageRef);
CGColorSpaceRef colorSpaceInfo = CGColorSpaceCreateDeviceRGB();

if (alphaInfo == kCGImageAlphaNone) {
    alphaInfo = kCGImageAlphaNoneSkipLast;
}

CGContextRef bitmap;

if (image.image.imageOrientation == UIImageOrientationUp || image.image.imageOrientation == UIImageOrientationDown) {
    bitmap = CGBitmapContextCreate(NULL, width, height, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, alphaInfo);

}
else {
    bitmap = CGBitmapContextCreate(NULL, height, width, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, alphaInfo);

}

if (image.image.imageOrientation == UIImageOrientationLeft) {
    CGContextRotateCTM(bitmap, radians(90));
    CGContextTranslateCTM(bitmap, 0, -height);
}
else if (image.image.imageOrientation == UIImageOrientationRight) {
    CGContextRotateCTM(bitmap, radians(-90));
    CGContextTranslateCTM(bitmap, -width, 0);
}
else if (image.image.imageOrientation == UIImageOrientationUp) {

}
else if (image.image.imageOrientation == UIImageOrientationDown) {
    CGContextTranslateCTM(bitmap, width, height);
    CGContextRotateCTM(bitmap, radians(-180.));
}


CGContextDrawImage(bitmap, CGRectMake(0, 0, width, height), imageRef);      


CGImageRef ref = CGBitmapContextCreateImage(bitmap);
UIImage *result = [UIImage imageWithCGImage:ref];

CGColorSpaceRelease(colorSpaceInfo);
CGContextRelease(bitmap);
CGImageRelease(ref);
thisCopyImage = result;
bgImage.image = thisCopyImage;

}
于 2013-05-29T08:58:33.750 回答