如果语句c＃中的单选按钮和事件检查

Question

我正在尝试在graphicsPanel1_Paint方法内编写If语句，其中仅当选择了某个单选按钮并单击一个按钮时才进行绘制。

这是我当前的代码：

private void graphicsPanel1_Paint(object sender, PaintEventArgs e)
    {

        for (int x = 0; x < mapSize.Width; x++)
        {
            for (int y = 0; y < mapSize.Height; y++)
            {
                Rectangle destRect = Rectangle.Empty;
                destRect.X = x * tileSize.Width;
                destRect.Y = y * tileSize.Height;
                destRect.Size = tileSize;

                destRect.X += graphicsPanel1.AutoScrollPosition.X;
                destRect.Y += graphicsPanel1.AutoScrollPosition.Y;

                Rectangle srcRect = Rectangle.Empty;
                srcRect.X = map[x, y].X * tileSize.Width;
                srcRect.Y = map[x, y].Y * tileSize.Height;
                srcRect.Size = tileSize;

                e.Graphics.DrawImage(Properties.Resources.colors, destRect, srcRect, GraphicsUnit.Pixel);
                buttonUse.Click += buttonUse_Click;

                if (radioButtonColor.Checked == true)
                {
                    e.Graphics.DrawImage(Properties.Resources.colors, destRect, srcRect, GraphicsUnit.Pixel);
                    graphicsPanel1.Invalidate();
                }

                else if (radioButtonDesert.Checked == true)
                {
                    e.Graphics.DrawImage(Properties.Resources.desert9x8x32x32, destRect, srcRect, GraphicsUnit.Pixel);
                    graphicsPanel1.Invalidate();
                }

                else if (radioButtonEarth.Checked == true)
                {
                    e.Graphics.DrawImage(Properties.Resources._default, destRect, srcRect, GraphicsUnit.Pixel);
                    graphicsPanel1.Invalidate();
                }

                else if (radioButtonMagic.Checked == true)
                {
                    e.Graphics.DrawImage(Properties.Resources.super4x4x64x64, destRect, srcRect, GraphicsUnit.Pixel);
                    graphicsPanel1.Invalidate();
                }

                e.Graphics.DrawRectangle(Pens.Black, destRect);
            }
        }
    }

显然，这是行不通的。

Answer 1

您需要添加一个全局变量来检查单击的按钮（或切换状态），然后将事件处理程序添加到buttonUse和OnPaint并使用以下代码：

bool btnUsePressed = false; // Declare a variable to track pressed button
buttonUse.Click += new EventHandler(this.buttonUse_Click); // e.g. in the Form_Load() 

// and then
private void graphicsPanel1_Paint(object sender, PaintEventArgs e)
{
    // ... YOU CODE UP TO
    if (radioButtonColor.Checked == true && btnUsePressed)
    {
        e.Graphics.DrawImage(Properties.Resources.colors, destRect, srcRect,GraphicsUnit.Pixel);
        graphicsPanel1.Invalidate();
    }
    // ... YOU CODE AFTER
}

void buttonUse_Click(Object sender, EventArgs e)
{
    if (btnUsePressed)
       btnUsePressed = false;
    else
    {
       btnUsePressed = true;
       graphicsPanel1.Refresh();
    }
}

Answer 2

Click（）是一个事件，因此您需要处理该事件，然后检查您的单选按钮。 所以像

buttonUse.Click()+= buttonUse_Click  
void buttonUse_Click(object sender, RoutedEventArgs e)
    {
       if (radioButtonColor.Checked == true)
    {
     e.Graphics.DrawImage(Properties.Resources.colors, destRect,     srcRect,GraphicsUnit.Pixel);
     graphicsPanel1.Invalidate();
    }
    }