如何使用C＃和iTextSharp以pdf格式添加图像？

I need your help adding an image to a PDF.

我需要您的帮助将图像添加到PDF。

I'm using:

string imgPath2 = localPath + "\\TempChartImages\\" + LegendPath;
img2.Save(imgPath2);
ith.WriteImage(imgPath2, 80);

But this code gives me the error:

但是这段代码给了我错误:

Use of unassigned local variable img2

使用未分配的局部变量img2

How can I solve this error?

我该如何解决这个错误?

6 个解决方案

#1

Here is the iTextSharp tutorial on images. Without seeing more of your code, it's tough to judge what piece of code from this you'll need.

这是关于图像的iTextSharp教程。如果没有看到更多的代码,很难判断出你需要的代码片段。

#2

When you declare a variable, in your case img2, without assigning a value it is pointing to absolutely nothing. Make sure you initialize img2 to something before using it.

当你声明一个变量时,在你的情况下img2,没有指定一个值,它指向绝对没有。确保在使用之前将img2初始化为某些内容。

I think what you want your img2.Save line to be changed to:

我想你想要将你的img2.Save行更改为:

Image img2 = Image.FromFile(yourInitialImageHere);  // You could be reading from memory as well.
img2.Save(imgPath2);

I could be way off though as your snippet of code is pretty vague.

我可能会离开,因为你的代码片段非常含糊。

#3

it's a hunch, but if you're assigning the value of img2 inside a Try-Catch block you might be hitting an exception that prevents the assignment from taking place. For example:

这是一种预感,但是如果你在Try-Catch块中分配img2的值,你可能会遇到阻止分配发生的异常。例如:

var img2;
try
{
    var x = 5 / 0; // Generate a DivideByZero exception
    img2 = GetImage(); // <-- the above exception will prevent this code from executing
}
catch
{
}
img2.Save(imgPath2); <-- img2 wasn't assigned, so another exception will occur

#4

You'll need some third-party tool for this.

你需要一些第三方工具。

#5

I believe you have to instantiate first the Image.

我相信你必须首先实例化Image。

Image img2 = new Image();

it solved my problems. Hope it will solve yours.

它解决了我的问题。希望它能解决你的问题。

#6

You have to create a getinstance of the image.

您必须创建图像的getinstance。

iTextSharp.text.Image img = iTextSharp.text.Image.GetInstance("path of the image");

#1