Note the call to showpage at the end of the top-level template.
注意顶层模板末尾处的showpage调用。
The root-level template works the same as that in the scatter plot example, rendering instructions for the elements and then calling showpage to render the contents of the graphics buffer.
root - level模板的工作原理与散点图示例中的工作原理相同，它将呈现元素的指令，然后调用showpage以呈现图形缓冲的内容。
应用推荐