Base64字符串到PNG图像对于itextsharp

Question

我有第三方控件允许签名捕获。我正在以base64字符串的形式从控件中捕获签名的图像。但我需要能够使用itextsharp将此图像标记为PDF文档，但无法将此base64字符串转换为可接受的格式（PNG）。

我需要使用itextsharp访问现有PDF文档的控件捕获的数据示例：

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 DU0NCw1MSA1NDYsNDYgNTQ3LDQ0IDU0Nyw0MyA1NDcsNDIgNTQ4LDQyIDU0OSw0MyA1NTAsNDQgNTUxLDQ0IDU1Myw0NCA1NTQsNDQgNTU1LDQ0IDU1Niw0NCA1NTYsNDMgNTU3LDQzIDU1Nyw0MiA1NTgsNDIgNTU4LDQxOw ==

Answer 1

控制开发者提供了一种方法。一切都好。