C# if else逻辑错误

Question

我在做某种逻辑但出现错误？

这里是我的代码

private static void DrawText(String text, Font font, Color textColor, Color backColor)
{
    Image img = new Bitmap(640, 360);
    Graphics drawing = Graphics.FromImage(img);

    Color color = textColor;
    if (text.Length <= 80) {
        Rectangle displayRectangle =
            new Rectangle(new Point(20, 100), new Size(img.Width - 1, img.Height - 1));
    } else {
        Rectangle displayRectangle =
            new Rectangle(new Point(20, 80), new Size(img.Width - 1, img.Height - 1));
    }
    StringFormat format1 = new StringFormat(StringFormatFlags.NoClip);
    StringFormat format2 = new StringFormat(format1);

     // ERROR ON NEXT LINE
    drawing.DrawString(text, font, Brushes.Red, (RectangleF)displayRectangle, format2);

    drawing.Dispose();
    string fileName = "f.png";
    string path = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, fileName);
    img.Save(path, System.Drawing.Imaging.ImageFormat.Png);

    img.Dispose();
}

错误是

Error 1 The name 'displayRectangle' does not exist in the current context C:\Documents and Settings\admin\My Documents\Visual Studio 2008>\Projects\template\template\Form1.cs 119 69 template

在这一行

drawing.DrawString(text, font, Brushes.Red, (RectangleF)displayRectangle, format2);

在 php 中逻辑是正确的，但是在 C# 中却出现错误？，如何在 C# 中执行此逻辑？

有什么帮助吗？ (仍在通过实践学习 C# :D )

Answer 1

将 Rectangle 定义移到 if else block 上方，这样它就不会超出范围。

Rectangle displayRectangle;

if (text.Length <= 80)
{
    displayRectangle = new Rectangle(new Point(20, 100), new Size(img.Width  img.Height - 1));
}
else
{
    displayRectangle = new Rectangle(new Point(20, 80), new Size(img.Width -  img.Height - 1));
}