Ios 调整UITableView ImageView的大小

如何在UITableViewCell中调整UIImageView的大小？我正在传入一个大图像（至少100x100px），因此图像本身不应该是问题（它应该随imageview缩小）

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通常，UITableViewCell中的UIImageView的高度和宽度为43点（或86像素）。我想把它缩小到20 x 20，但这没什么用。我遗漏了什么吗？

您无法更改uitableviewcell的uiimageview的帧。您可以从下面选择一个选项

创建一个自定义单元格并根据需要放置uiimageview（这是最好的解决方案，我更喜欢这个）

在您的单元格中使用核心图形for row索引路径：

CGSize itemSize = CGSizeMake(width, height);
UIGraphicsBeginImageContext(itemSize);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[cell.imageView.image drawInRect:imageRect];
cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

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我希望以下功能对您有用：

+(UIImage*)resizeImage:(UIImage *)image width:(int)width height:(int)height  {

CGFloat targetWidth = width;
CGFloat targetHeight = height;

CGImageRef imageRef = [image CGImage];
CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef);
CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef);

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

CGContextRef bitmap;

if (image.imageOrientation == UIImageOrientationUp || image.imageOrientation == UIImageOrientationDown) {
    bitmap = CGBitmapContextCreate(NULL, targetWidth, targetHeight, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);

} else {
    bitmap = CGBitmapContextCreate(NULL, targetHeight, targetWidth, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);

}   


// In the right or left cases, we need to switch scaledWidth and scaledHeight,
// and also the thumbnail point
if (image.imageOrientation == UIImageOrientationLeft) {
    CGContextRotateCTM (bitmap, radians(90));
    CGContextTranslateCTM (bitmap, 0, -targetHeight);

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

} else if (image.imageOrientation == UIImageOrientationUp) {
    // NOTHING
} else if (image.imageOrientation == UIImageOrientationDown) {
    CGContextTranslateCTM (bitmap, targetWidth, targetHeight);
    CGContextRotateCTM (bitmap, radians(-180.));
}

CGContextDrawImage(bitmap, CGRectMake(0, 0, targetWidth, targetHeight), imageRef);
CGImageRef ref = CGBitmapContextCreateImage(bitmap);
UIImage* newImage = [UIImage imageWithCGImage:ref];

CGContextRelease(bitmap);
CGImageRelease(ref);

return newImage; 
}

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为什么不使用自定义单元格？更好地将UITableViewCell子类化感谢您的回答。当我尝试第二种方法时，它会调整imageview的大小，但我的图像随后会变得像素化。考虑到我正在缩小规模，这对我来说没有多大意义。有什么想法吗？

+(UIImage*)resizeImage:(UIImage *)image width:(int)width height:(int)height  {

CGFloat targetWidth = width;
CGFloat targetHeight = height;

CGImageRef imageRef = [image CGImage];
CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef);
CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef);

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

CGContextRef bitmap;

if (image.imageOrientation == UIImageOrientationUp || image.imageOrientation == UIImageOrientationDown) {
    bitmap = CGBitmapContextCreate(NULL, targetWidth, targetHeight, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);

} else {
    bitmap = CGBitmapContextCreate(NULL, targetHeight, targetWidth, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);

}   


// In the right or left cases, we need to switch scaledWidth and scaledHeight,
// and also the thumbnail point
if (image.imageOrientation == UIImageOrientationLeft) {
    CGContextRotateCTM (bitmap, radians(90));
    CGContextTranslateCTM (bitmap, 0, -targetHeight);

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

} else if (image.imageOrientation == UIImageOrientationUp) {
    // NOTHING
} else if (image.imageOrientation == UIImageOrientationDown) {
    CGContextTranslateCTM (bitmap, targetWidth, targetHeight);
    CGContextRotateCTM (bitmap, radians(-180.));
}

CGContextDrawImage(bitmap, CGRectMake(0, 0, targetWidth, targetHeight), imageRef);
CGImageRef ref = CGBitmapContextCreateImage(bitmap);
UIImage* newImage = [UIImage imageWithCGImage:ref];

CGContextRelease(bitmap);
CGImageRelease(ref);

return newImage; 
}