参数:
base64图片数据, 要求带data:image/png;base64,标志头
返回: 图片文件名
例子:
<!--{ffwbms_func base64toimg,aa,"data:image/png;base64,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"}-->
<!--{ffwbms_see $aa}-->
返回：
/upfiles/202407/20240723024123OmA4MZ.png
