处理ImageList对象的适当方法是什么?
假设我有一个私有ImageList imageList成员的类.现在,我在某个时刻执行以下代码:
// Basically, lazy initialization.
if (imageList == null)
{
imageList = new ImageList();
Image[] images = Provider.CreateImages(...);
foreach (var image in images)
{
// Does the 'ImageList' perform implicit copying here
// or does it aggregate a reference?
imageList.Images.Add(image);
// Do I need to do this?
//image.Dispose();
}
}
return imageList;
在同一个类中,我有Dispose方法实现,它按以下方式执行:
public void Dispose()
{
if (!disposed)
{
// Is this enough?
if (imageList != null)
imageList.Dispose();
disposed = true;
}
}
我确定这段代码存在一些潜在的问题,所以请你帮我纠正一下.
解决方法:
是的,它会复制一份.请注意下面的CreateBitMap调用.因此,为了尽可能降低资源使用率,您应该取消注释您的配置线.
private int Add(ImageList.Original original, ImageList.ImageCollection.ImageInfo imageInfo)
{
if (original == null || original.image == null)
throw new ArgumentNullException("value");
int num = -1;
if (original.image is Bitmap)
{
if (this.owner.originals != null)
num = this.owner.originals.Add((object) original);
if (this.owner.HandleCreated)
{
bool ownsBitmap = false;
Bitmap bitmap = this.owner.CreateBitmap(original, out ownsBitmap);
num = this.owner.AddToHandle(original, bitmap);
if (ownsBitmap)
bitmap.Dispose();
}
}
else
{
if (!(original.image is Icon))
throw new ArgumentException(System.Windows.Forms.SR.GetString("ImageListBitmap"));
if (this.owner.originals != null)
num = this.owner.originals.Add((object) original);
if (this.owner.HandleCreated)
num = this.owner.AddIconToHandle(original, (Icon) original.image);
}
if ((original.options & ImageList.OriginalOptions.ImageStrip) != ImageList.OriginalOptions.Default)
{
for (int index = 0; index < original.nImages; ++index)
this.imageInfoCollection.Add((object) new ImageList.ImageCollection.ImageInfo());
}
else
{
if (imageInfo == null)
imageInfo = new ImageList.ImageCollection.ImageInfo();
this.imageInfoCollection.Add((object) imageInfo);
}
if (!this.owner.inAddRange)
this.owner.OnChangeHandle(new EventArgs());
return num;
}
当ImageList处理时,它会处理所有图像的副本.所以,再次,是的,除非取消注释您的其他配置线,否则在表单关闭时处理它是正确的.
protected override void Dispose(bool disposing)
{
if (disposing)
{
if (this.originals != null)
{
foreach (ImageList.Original original in (IEnumerable) this.originals)
{
if ((original.options & ImageList.OriginalOptions.OwnsImage) != ImageList.OriginalOptions.Default)
((IDisposable) original.image).Dispose();
}
}
this.DestroyHandle();
}
base.Dispose(disposing);
}