我的面板上有几层图纸

Question

我创建了一个面板，并使用 DrawString 和 DrawRectangle 在上面放置了文本。要绘制面板，我使用了 Paint 事件和 Invalidate 方法，但是当调用 Invalidate 时，我得到以下结果（背景颜色透明）：My panel with drawstring

正如你所看到的，文本被绘制出来了，但它后面的内容并没有消失，就好像 Invalidate 已经完成了一半的工作。

我已将 DoubleBuffered 设置为 true 并尝试 Graphics.Clear 但没有成功。

有人可以帮助我吗？

有代码:

            int x = 0;
        int y = arrowUpHeight;
        int traceIndex = 0;
        lock (_lockDraw)
        {
            while (y < Height)
            {
                rect = new Rectangle(x, y, Width, 20);
                r = new Rectangle(x, y, rect.Width + 1, rect.Height + 1);
                bufferGraphics.SetClip(r);

                if (traceIndex < traceList.Count)
                {
                    if (traceIndex < numberOfTraces)
                    {
                        Line data = traceList[traceIndex];
                        if (traceIndex % 2 == 0)
                        {
                            bufferGraphics.FillRectangle(brushEven, rect);
                        }
                        else
                        {
                            bufferGraphics.FillRectangle(brushOdd, rect);
                        }
                        if (y < mousePositionY && mousePositionY < y + 20)
                        {
                            traceSelected = true;
                            traceList[traceIndex].Selected = true;
                            listLinesVisible[traceIndex].Selected = true;
                            listLines[listLines.IndexOf(traceList[traceIndex])].Selected = true;
                            indexRightClick = traceIndex;
                        }
                        else
                        {
                            if (listLines.IndexOf(traceList[traceIndex]) < listLines.Count && listLines.IndexOf(traceList[traceIndex]) >= 0)
                            {
                                traceList[traceIndex].Selected = false;
                                listLinesVisible[traceIndex].Selected = false;
                                listLines[listLines.IndexOf(traceList[traceIndex])].Selected = false;
                            }
                        }
                        if (traceList[traceIndex].Message.ToUpper().Contains(textBoxRUISearch.MyTextBox.Text.ToUpper()) && textBoxRUISearch.MyTextBox.Text != String.Empty)
                        {
                            bufferGraphics.FillRectangle(searchBrush, rect);
                        }
                        if (traceList[traceIndex].Selected)
                        {
                            //doesn't work correctly for the moment when scrolling
                            bufferGraphics.FillRectangle(selectedBrush, rect);
                            bufferGraphics.DrawString(data.Date, traceFont, selectedStringBrush, xTime, y);
                            bufferGraphics.DrawString(data.LevelString, traceFont, selectedStringBrush, xLevel, y);
                            bufferGraphics.DrawString(data.Source, traceFont, selectedStringBrush, xSource, y);
                            if (data.Attachment != null)
                            {
                                bufferGraphics.DrawString("Attachment : ", traceFont, selectedStringBrush, xMessage, y);
                                bufferGraphics.DrawString(data.Message, traceFont, selectedStringBrush, xMessage + (xMessage / 5), y);
                            }
                            else
                                bufferGraphics.DrawString(data.Message, traceFont, selectedStringBrush, xMessage, y);
                        }
                        else
                        {
                            bufferGraphics.DrawString(data.Date, traceFont, stringBrush, xTime, y);

                            // Info = 1, Warning = 2, Error = 3, Debug = 5, Special = 6
                            switch (data.LevelString)
                            {
                                case "Info":
                                    bufferGraphics.DrawString(data.LevelString, traceFont, brushInfo, xLevel, y);
                                    break;
                                case "Warning":
                                    bufferGraphics.DrawString(data.LevelString, traceFont, brushWarning, xLevel, y);
                                    break;
                                case "Error":
                                    bufferGraphics.DrawString(data.LevelString, traceFont, brushError, xLevel, y);
                                    break;
                                case "Debug":
                                    bufferGraphics.DrawString(data.LevelString, traceFont, brushDebug, xLevel, y);
                                    break;
                                default:
                                    break;
                            }
                            bufferGraphics.DrawString(data.Source, traceFont, stringBrush, xSource, y);

                            if (data.Attachment != null)
                            {
                                bufferGraphics.DrawString("Attachment : ", traceFont, brushAttachment, xMessage, y);
                                bufferGraphics.DrawString(data.Message, traceFont, stringBrush, xMessage + (xMessage / 5), y);
                            }
                            else
                                bufferGraphics.DrawString(data.Message, traceFont, stringBrush, xMessage, y);
                        }
                        bufferGraphics.DrawRectangle(Pens.LightGray, rect);
                        //
                        //                      if (data.selected)
                        //                      {
                        //                          Color color = Color.FromArgb(100, 0, 0, 255);
                        //                          Brush brush = new SolidBrush(color);
                        //                          _bufferGraphics.FillRectangle(brush, rect);
                        //                      }
                    }
                    else
                    {
                        if (listLines.ElementAtOrDefault(listLines.Count - 1) != null)
                            listLines.RemoveAt(listLines.Count - 1);

                        if (listLinesVisible.ElementAtOrDefault(listLinesVisible.Count - 1) != null)
                            listLinesVisible.RemoveAt(listLinesVisible.Count - 1);

                        y -= 20;
                    }
                }
                else
                    bufferGraphics.FillRectangle(brushUnderTraces, rect);

                y += 20;
                traceIndex++;
            }
        }
        this.panelTraces.Invalidate();

其中 bufferGraphics 是我的 Graphics 对象。

Answer 1

好的，我找到了解决方案：我用了一种方法，然后我画了。我在 Paint 中设置了我的方法主体，它工作正常。我将 bufferGraphics 替换为 e.Graphics.

感谢那些试图帮助我的人（我的英语很糟糕所以恭喜你理解我）。

我的面板上有几层图纸

I have several layers of drawings on my panel

c#

winforms

panel

paint