DrawImage无法正确定位切片图像
本文关键字：定位 切片 图像 DrawImage | 更新日期: 2023-09-27 18:03:05
几天来，我一直在试图弄清楚为什么我的九段代码没有像预期的那样工作。据我所知，似乎有一个问题与图像。DrawImage方法处理我的九个切片图像不正确。因此，我的问题是如何补偿在紧凑框架上运行代码时执行的不正确缩放。我可能会补充说，当在完整的框架环境中运行时，这些代码当然可以完美地工作。这个问题只有在将图像缩放到更大的图像时才会发生，而不是相反。下面是代码片段:
public class NineSliceBitmapSnippet
{
private Bitmap m_OriginalBitmap;
public int CornerLength { get; set; }
/// <summary>
/// Initializes a new instance of the NineSliceBitmapSnippet class.
/// </summary>
public NineSliceBitmapSnippet(Bitmap bitmap)
{
CornerLength = 5;
m_OriginalBitmap = bitmap;
}
public Bitmap ScaleSingleBitmap(Size size)
{
Bitmap scaledBitmap = new Bitmap(size.Width, size.Height);
int[] horizontalTargetSlices = Slice(size.Width);
int[] verticalTargetSlices = Slice(size.Height);
int[] horizontalSourceSlices = Slice(m_OriginalBitmap.Width);
int[] verticalSourceSlices = Slice(m_OriginalBitmap.Height);
using (Graphics graphics = Graphics.FromImage(scaledBitmap))
{
using (Brush brush = new SolidBrush(Color.Fuchsia))
{
graphics.FillRectangle(brush, new Rectangle(0, 0, size.Width, size.Height));
}
int horizontalTargetOffset = 0;
int verticalTargetOffset = 0;
int horizontalSourceOffset = 0;
int verticalSourceOffset = 0;
for (int x = 0; x < horizontalTargetSlices.Length; x++)
{
verticalTargetOffset = 0;
verticalSourceOffset = 0;
for (int y = 0; y < verticalTargetSlices.Length; y++)
{
Rectangle destination = new Rectangle(horizontalTargetOffset, verticalTargetOffset, horizontalTargetSlices[x], verticalTargetSlices[y]);
Rectangle source = new Rectangle(horizontalSourceOffset, verticalSourceOffset, horizontalSourceSlices[x], verticalSourceSlices[y]);
graphics.DrawImage(m_OriginalBitmap, destination, source, GraphicsUnit.Pixel);
verticalTargetOffset += verticalTargetSlices[y];
verticalSourceOffset += verticalSourceSlices[y];
}
horizontalTargetOffset += horizontalTargetSlices[x];
horizontalSourceOffset += horizontalSourceSlices[x];
}
}
return scaledBitmap;
}
public int[] Slice(int length)
{
int cornerLength = CornerLength;
if (length <= (cornerLength * 2))
throw new Exception("Image to small for sliceing up");
int[] slices = new int[3];
slices[0] = cornerLength;
slices[1] = length - (2 * cornerLength);
slices[2] = cornerLength;
return slices;
}
}
我的问题是，有人知道我该如何补偿不正确的缩放吗?
丹
经过反复试验，我终于找到了解决问题的办法。缩放问题一直存在于上中心、右中心、下中心和左中心切片，因为它们总是按照九片缩放的逻辑只向一个方向拉伸。如果我在应用正确的拉伸之前对这些切片应用临时的正方形拉伸，那么最终的位图将是正确的。同样，这个问题只在Windows CE设备(智能设备)的。net Compact Framework中可见。这里是一个代码片段，在CF中调整了这个bug。我现在唯一担心的是，由于纠正代码，得到方形拉伸的切片将占用更多的内存。另一方面，这一步只需要很短的时间，所以我可能会侥幸逃脱。;)
public class NineSliceBitmapSnippet
{
private Bitmap m_OriginalBitmap;
public int CornerLength { get; set; }
public NineSliceBitmapSnippet(Bitmap bitmap)
{
CornerLength = 5;
m_OriginalBitmap = bitmap;
}
public Bitmap Scale(Size size)
{
if (m_OriginalBitmap != null)
{
return ScaleSingleBitmap(size);
}
return null;
}
public Bitmap ScaleSingleBitmap(Size size)
{
Bitmap scaledBitmap = new Bitmap(size.Width, size.Height);
int[] horizontalTargetSlices = Slice(size.Width);
int[] verticalTargetSlices = Slice(size.Height);
int[] horizontalSourceSlices = Slice(m_OriginalBitmap.Width);
int[] verticalSourceSlices = Slice(m_OriginalBitmap.Height);
using (Graphics graphics = Graphics.FromImage(scaledBitmap))
{
using (Brush brush = new SolidBrush(Color.Fuchsia))
{
graphics.FillRectangle(brush, new Rectangle(0, 0, size.Width, size.Height));
}
int horizontalTargetOffset = 0;
int verticalTargetOffset = 0;
int horizontalSourceOffset = 0;
int verticalSourceOffset = 0;
for (int x = 0; x < horizontalTargetSlices.Length; x++)
{
verticalTargetOffset = 0;
verticalSourceOffset = 0;
for (int y = 0; y < verticalTargetSlices.Length; y++)
{
Rectangle destination = new Rectangle(horizontalTargetOffset, verticalTargetOffset, horizontalTargetSlices[x], verticalTargetSlices[y]);
Rectangle source = new Rectangle(horizontalSourceOffset, verticalSourceOffset, horizontalSourceSlices[x], verticalSourceSlices[y]);
bool isWidthAffectedByVerticalStretch = (y == 1 && (x == 0 || x == 2) && destination.Height > source.Height);
bool isHeightAffectedByHorizontalStretch = (x == 1 && (y == 0 || y == 2) && destination.Width > source.Width);
if (isHeightAffectedByHorizontalStretch)
{
BypassDrawImageError(graphics, destination, source, Orientation.Horizontal);
}
else if (isWidthAffectedByVerticalStretch)
{
BypassDrawImageError(graphics, destination, source, Orientation.Vertical);
}
else
{
graphics.DrawImage(m_OriginalBitmap, destination, source, GraphicsUnit.Pixel);
}
verticalTargetOffset += verticalTargetSlices[y];
verticalSourceOffset += verticalSourceSlices[y];
}
horizontalTargetOffset += horizontalTargetSlices[x];
horizontalSourceOffset += horizontalSourceSlices[x];
}
}
return scaledBitmap;
}
private void BypassDrawImageError(Graphics graphics, Rectangle destination, Rectangle source, Orientation orientationAdjustment)
{
Size adjustedSize = Size.Empty;
switch (orientationAdjustment)
{
case Orientation.Horizontal:
adjustedSize = new Size(destination.Width, destination.Width);
break;
case Orientation.Vertical:
adjustedSize = new Size(destination.Height, destination.Height);
break;
default:
break;
}
using (Bitmap quadScaledBitmap = new Bitmap(adjustedSize.Width, adjustedSize.Height))
{
using (Graphics tempGraphics = Graphics.FromImage(quadScaledBitmap))
{
tempGraphics.Clear(Color.Fuchsia);
tempGraphics.DrawImage(m_OriginalBitmap, new Rectangle(0, 0, adjustedSize.Width, adjustedSize.Height), source, GraphicsUnit.Pixel);
}
graphics.DrawImage(quadScaledBitmap, destination, new Rectangle(0, 0, quadScaledBitmap.Width, quadScaledBitmap.Height), GraphicsUnit.Pixel);
}
}
public int[] Slice(int length)
{
int cornerLength = CornerLength;
if (length <= (cornerLength * 2))
throw new Exception("Image to small for sliceing up");
int[] slices = new int[3];
slices[0] = cornerLength;
slices[1] = length - (2 * cornerLength);
slices[2] = cornerLength;
return slices;
}
}