Javascript 使用字节数组添加多个ITextSharp二进制图像会导致IndexOutOfRangeException

我正在使用ITextSharp和html2canvas添加二进制图像和生成PDF

下面是我的

codebhind

代码的一个片段

var overallResultsBase64string = hdnOverallResults.Value.Replace("data:image/png;base64,", "");
var appServerCapacityBase64string = hdnAppServerCapacity.Value.Replace("data:image/png;base64,", "");
var appPerformanceBase64string = hdnAppPerformance.Value.Replace("data:image/png;base64,", "");
var dbServerCapacityBase64string = hdnDBServerCapacity.Value.Replace("data:image/png;base64,", "");
var dbPerformanceBase64string = hdnDBPerformance.Value.Replace("data:image/png;base64,", "");

iTextSharp.text.Image overallResultsImg, appServerCapacityImg, appPerformanceImg
  , dbServerCapacityImg, dbPerformanceImg;

byte[] overallResultsBytes = Convert.FromBase64String(overallResultsBase64string);
overallResultsImg = iTextSharp.text.Image.GetInstance(overallResultsBytes);
byte[] appServerCapacityBytes = Convert.FromBase64String(appServerCapacityBase64string);
appServerCapacityImg = iTextSharp.text.Image.GetInstance(appServerCapacityBytes);
byte[] appPerformanceBytes = Convert.FromBase64String(appPerformanceBase64string);
appPerformanceImg = iTextSharp.text.Image.GetInstance(appPerformanceBytes);
byte[] dbServerCapacityBytes = Convert.FromBase64String(dbServerCapacityBase64string);
dbServerCapacityImg = iTextSharp.text.Image.GetInstance(dbServerCapacityBytes);
byte[] dbPerformanceBytes = Convert.FromBase64String(dbPerformanceBase64string);
dbPerformanceImg = iTextSharp.text.Image.GetInstance(dbPerformanceBytes);

document.Add(overallResultsImg);
document.Add(new Paragraph("OVERALL APPLICATION PERFORMANCE"));
document.Add(appPerformanceImg);
document.Add(dbPerformanceImg);
document.Add(new Paragraph("OVERALL SERVER CAPACITY"));
document.Add(appServerCapacityImg);
document.Add(dbServerCapacityImg);

var-appServerCapacityBase64string

为

NULL

，它会在其上引发

IndexOutOfBounds

异常

byte[] appServerCapacityBytes = Convert.FromBase64String(appServerCapacityBase64string);
appServerCapacityImg = iTextSharp.text.Image.GetInstance(appServerCapacityBytes);

下面我的Javascript html2canvas代码是否有问题？请查收

<script>
   html2canvas($("#overallResultsDiv"), {
        onrendered: function (canvas) {
            // canvas is the final rendered <canvas> element
            var myImage = canvas.toDataURL("image/png");
            document.getElementById("hdnOverallResults").value = myImage;
        }
    });

    html2canvas($("#appServerCapacityDiv"), {
        onrendered: function (canvas) {
            // canvas is the final rendered <canvas> element
            var myImage = canvas.toDataURL("image/png");
           $("#hdnAppServerCapacity").value = myImage;
        }
    });

    html2canvas($("#appPerformanceDiv"), {
        onrendered: function (canvas) {
            // canvas is the final rendered <canvas> element
            var myImage = canvas.toDataURL("image/png");
            document.getElementById("hdnAppPerformance").value = myImage;
        }
    });

    html2canvas($("#dbServerCapacityDiv"), {
        onrendered: function (canvas) {
            // canvas is the final rendered <canvas> element
            var myImage = canvas.toDataURL("image/png");
            document.getElementById("hdnDBServerCapacity").value = myImage;
        }
    });

    html2canvas($("#dbPerformanceDiv"), {
        onrendered: function (canvas) {
            // canvas is the final rendered <canvas> element
            var myImage = canvas.toDataURL("image/png");
            document.getElementById("hdnDBPerformance").value = myImage;
        }
    });
</script>

html2canvas（$（“#总体结果div”）{
onrendered：函数（画布）{
//画布是最终渲染的元素
var myImage=canvas.toDataURL（“image/png”）；
document.getElementById（“hdnoveralResults”）.value=myImage；
}
});
html2canvas（$（“#appServerCapacityDiv”）{
onrendered：函数（画布）{
//画布是最终渲染的元素
var myImage=canvas.toDataURL（“image/png”）；
$（“#hdnAppServerCapacity”）.value=myImage；
}
});
html2canvas（$（“#appPerformanceDiv”）{
onrendered：函数（画布）{
//画布是最终渲染的元素
var myImage=canvas.toDataURL（“image/png”）；
document.getElementById（“hdnAppPerformance”）.value=myImage；
}
});
html2canvas（$（“#dbServerCapacityDiv”）{
onrendered：函数（画布）{
//画布是最终渲染的元素
var myImage=canvas.toDataURL（“image/png”）；
document.getElementById（“hdnDBServerCapacity”）.value=myImage；
}
});
html2canvas（$（“#dbPerformanceDiv”）{
onrendered：函数（画布）{
//画布是最终渲染的元素
var myImage=canvas.toDataURL（“image/png”）；
document.getElementById（“hdnDBPerformance”）.value=myImage；
}
});

---

仅第一个html2canvas成功将

base64字符串

作为值传递给相应的

HiddenField

，并在

codebeader

中成功访问。我的脚本使

5个隐藏字段返回NULL，有什么问题吗？
您是否尝试过更改
var myImage=canvas.toDataURL（“image/png”）到函数中的不同名称