无法将整数从javascript传递到npapi插件 [英] Unable to pass integer from javascript to npapi plugin
问题描述
我正在编写一个简单的napapi插件，我必须在html页面中打印从javascript函数传递的值。但是我在做这件事时遇到了问题。它在firefox上运行正常。但我想在qt fancybrowser示例中做到这一点。无论我在javascript代码中传递什么值，打印的值始终为0.
I am writing a simple napapi plugin where I have to print the value passed from javascript function in html page. But I am facing problem while doing it. It works properly on firefox. But I want to do it on qt fancybrowser example. The value printed is always 0 no matter whatever value I pass in javascript code.
javascript代码如下：
The javascript code is as follows :
<html>
.....
<script>
function process_data()
{
PluginObject = document.getElementById("Object");
var i =100;
if(PluginObject){
ret = PluginObject.process_Data(i);
}
}
</script>
....
</html>
插件代码如下：
.....
bool ScriptableObject::process_Data(const NPVariant* args, uint32_t argCount, NPVariant* result)
{
printf(" process_Data\n");
printf("\t argCount : %d\n",argCount);
int tempi =args[0].value.intValue;
int tempf =args[0].value.doubleValue;
printf("type: %d type: %u\n",args[0].type,args[0].type);
printf("tempi : %d tempf : %f\n",tempi,tempf);
}
......
输出如下：
process_Data
argCount : 1
type: 4 type: 4
tempi : 0 tempf : 0.000000
实际上它应该打印100，这是从javascript传递给var i的值。
Actually it should print 100 which is the value passed in var i from javascript.
欢迎任何建议/意见
提前致谢
推荐答案
在为NPAPI方法提供数字参数时，未定义是否会收到 Int32 或双变体，因此您必须在代码中处理这两种情况。
此外， NPVARIANT_TO _ * 宏仅提取相应的值 - 它们不进行任何转换。
When providing a number argument to a NPAPI method, it is undefined whether you will receive a Int32 or Double variant, so you have to handle both cases in your code.
Furthermore, the NPVARIANT_TO_* macros only extract the respective value - they don't do any conversion.
要从任何数字参数中提取整数，您必须编写自己的代码，例如类似于：
To extract an integer from any numeric argument, you have to write your own code, e.g. something like:
bool convertToInt(const NPVariant& v, int32_t& out) {
if (NPVARIANT_IS_INT32(v)) {
out = NPVARIANT_TO_INT32(v);
return true;
}
if (NPVARIANT_IS_DOUBLE(v)) {
out = NPVARIANT_TO_DOUBLE(v);
return true;
}
// not a numeric variant
return false;
}
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