System.Drawing - 参数无效

经过更多测试后，我发现此问题可能是由于图像未及时加载以克隆到位图并显示所致。这可能还是不可能？

注意：是的，标题中还有其他与此错误相关的问题，但从一些研究来看，它似乎是一个含糊不清的错误，有许多可能的原因。我没有发现任何与我的情况相同的问题。

我收到以下错误。

System.ArgumentException was unhandled
HResult=-2147024809
Message=Parameter is not valid.
Source=System.Drawing

它源于这段代码。看起来是随机的（即，有时有效，有时无效。在不重新启动 VS 和重建项目的情况下连续运行的次数越多，失败的可能性就越大）：

private Bitmap GetSprite(bool anim, int tsIndex, int tileIdx) {
    System.Drawing.Rectangle cloneRect;
    string prefix = (anim) ? "A" : "S";
    using (Bitmap b = new Bitmap(prefix + tsIndex.ToString() + ".png")) {
        if (anim) {
            cloneRect = new System.Drawing.Rectangle(BaseObjects.A_AnimSpriteSets[tsIndex].StaticRecs[tileIdx].X, BaseObjects.A_AnimSpriteSets[tsIndex].StaticRecs[tileIdx].Y, BaseObjects.A_AnimSpriteSets[tsIndex].RecWidth, BaseObjects.A_AnimSpriteSets[tsIndex].RecHeight);
        } else {
            cloneRect = new System.Drawing.Rectangle(BaseObjects.A_StaticSpriteSets[tsIndex].StaticRecs[tileIdx].X, BaseObjects.A_StaticSpriteSets[tsIndex].StaticRecs[tileIdx].Y, BaseObjects.A_StaticSpriteSets[tsIndex].RecWidth, BaseObjects.A_StaticSpriteSets[tsIndex].RecHeight);
        }
        return b.Clone(cloneRect, b.PixelFormat);
    }
}

具体来说，第四行：

using (Bitmap b = new Bitmap(prefix + tsIndex.ToString() + ".png"))

代码的简化目标是根据精灵集索引和精灵索引从精灵集中返回包含精灵的位图。该位图显示在 PictureBox 中，直到更改为其他图像为止。我确实知道这个逻辑是有效的；这不是这里的问题。我用来测试的.png是384*256。

所有参数都设置正确，所有引用的文件都在那里，一切似乎都井然有序。最奇怪的是，有时有效，有时无效。这让我相信这可能是内存泄漏System.Drawing本身，但我似乎无法追踪它。

编辑：更新了代码并添加了 StackTrace。尽管在不再使用位图时对其进行了处理，但仍然存在相同的问题（有关如何处理位图的示例，请参阅下面的代码）。

if (Sprite.Image != null) { Sprite.Image.Dispose(); }
    Sprite.Image = GetSprite(true, tsIdx, tileIdx);

堆栈跟踪：

System.ArgumentException was unhandled
  HResult=-2147024809
  Message=Parameter is not valid.
  Source=System.Drawing
  StackTrace:
       at System.Drawing.Bitmap..ctor(String filename)
       at CreationTool.Main.GetSprite(Boolean anim, Int32 tsIndex, Int32 tileIdx) in F:\~\~\CreationTool\Main.cs:line 420
       at CreationTool.Main.Input_EnemySprite_SelectedIndexChanged(Object sender, EventArgs e) in F:\~\~\CreationTool\Main.cs:line 107
       at System.Windows.Forms.ComboBox.OnSelectedIndexChanged(EventArgs e)
       at System.Windows.Forms.ComboBox.set_SelectedIndex(Int32 value)
       at CreationTool.States.State_Enemy.populateForm() in F:\~\~\CreationTool\States\State_Enemy.cs:line 28
       at CreationTool.States.State_Enemy.Load(String name) in F:\~\~\CreationTool\States\State_Enemy.cs:line 22
       at CreationTool.Main.btnLoad_Click(Object sender, EventArgs e) in F:\~\~\CreationTool\Main.cs:line 174
       at System.Windows.Forms.Control.OnClick(EventArgs e)
       at System.Windows.Forms.Button.OnClick(EventArgs e)
       at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
       at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.ButtonBase.WndProc(Message& m)
       at System.Windows.Forms.Button.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.Run(Form mainForm)
       at CreationTool.Program.Main() in F:\~\~\CreationTool\Program.cs:line 15
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()

哇，这段代码正在泄漏句柄。您需要处置所有实现的类型IDisposable，在 System.Drawing 程序集 (GDI+) 中有相当多的类型：

private Bitmap GetSprite(bool anim, int tsIndex, int tileIdx)
{
    Rectangle cloneRect;
    string prefix = (anim) ? "A" : "S";
    using (Bitmap b = new Bitmap(prefix + tsIndex.ToString() + ".png"))
    {
        if (anim)
        {
            cloneRect = new Rectangle(BaseObjects.A_AnimSpriteSets[tsIndex].StaticRecs[tileIdx].X, BaseObjects.A_AnimSpriteSets[tsIndex].StaticRecs[tileIdx].Y, BaseObjects.A_AnimSpriteSets[tsIndex].RecWidth, BaseObjects.A_AnimSpriteSets[tsIndex].RecHeight);
        }
        else
        {
            cloneRect = new Rectangle(BaseObjects.A_StaticSpriteSets[tsIndex].StaticRecs[tileIdx].X, BaseObjects.A_StaticSpriteSets[tsIndex].StaticRecs[tileIdx].Y, BaseObjects.A_StaticSpriteSets[tsIndex].RecWidth, BaseObjects.A_StaticSpriteSets[tsIndex].RecHeight);
        }

        return b.Clone(cloneRect, b.PixelFormat);
    }
}

还要确保您还通过将调用者包装在一个using陈述：

using (Bitmap b = GetSprite(true, 0, 5))
{
    // do whatever you needed to do with the bitmap here
}