ActionScript 编译器 UncaughtErrorEvent

Question

使用 asc2 编译 AIR 应用程序后，我发现在捕获 UncaughtErrorEvent 时缺少错误堆栈跟踪。

示例代码如下：

var root:Sprite = this;
root.loaderInfo.uncaughtErrorEvents.addEventListener(UncaughtErrorEvent.UNCAUGHT_ERROR,errorHandle);
throw new Error("test");

protected function errorHandle(event:UncaughtErrorEvent):void
        {
            var message:String; 
            if (event.error is Error) { 
                message = Error(event.error).message; 
                message+="\n"+Error(event.error).getStackTrace();
            } else if (event.error is ErrorEvent) { 
                message = ErrorEvent(event.error).text;
            } else { 
                message = event.error.toString(); 
            } 
        }

在使用 ASC1 时，我可以在错误句柄中看到完整的堆栈跟踪。但是使用 ASC2，只是一个空的堆栈跟踪。

有人有同样的问题吗？

如何获得 UncaughtErrorEvent 堆栈跟踪？

Answer 1

不要将event.error 转换为Error，如：

Error(event.error).getStackTrace()

获取错误的堆栈跟踪以字符串形式返回错误构造时的错误调用堆栈。请注意，堆栈跟踪的行号是强制转换的行。

改为从event.error 调用getStackTrace()，如下所示：

event.error.getStackTrace()

根据您的示例，堆栈上没有什么重要的。

添加递归有助于证明问题：

package
{
    import flash.display.Sprite;
    import flash.events.UncaughtErrorEvent;

    public class ExceptionTest extends Sprite
    {
        public function ExceptionTest()
        {
            super();

            loaderInfo.uncaughtErrorEvents.addEventListener(UncaughtErrorEvent.UNCAUGHT_ERROR, uncaughtErrorHandler);
            recursion();
        }

        protected function recursion(depth:uint=0):void
        {
            if (depth == 5)
                throw new Error("test");
            else
                recursion(++depth);
        }

        protected function uncaughtErrorHandler(event:UncaughtErrorEvent):void
        {
            trace(event.error.getStackTrace());
        }
    }
}

...会产生：

Error: test
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:19]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:13]
[SWF] Users:jsturges:dev:flash-workspace:X:bin-debug:ExceptionTest.swf - 1,745 bytes after decompression
Error: test
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:19]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:13]

如果将 uncaughtErrorHandler() 更改为您的示例转换为 Error，如下所示：

protected function uncaughtErrorHandler(event:UncaughtErrorEvent):void
{
    trace(Error(event.error).getStackTrace());
}

调试器捕获到异常，但getStackTrace 是强制转换的行：

Error: test
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:19]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest/recursion()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:21]
    at ExceptionTest()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:13]
[SWF] Users:jsturges:dev:flash-workspace:X:bin-debug:ExceptionTest.swf - 1,519 bytes after decompression
Error: Error: test
    at ExceptionTest/uncaughtErrorHandler()[/Users/jsturges/dev/flash-workspace/X/src/ExceptionTest.as:26]

从 Flash Player 10.1 开始，将 AS1 和 AS2 编组为支持 UncaughtErrorEvent 的 AS3 也可能存在细微差别。

除此之外，确保每个 ActionScript 版本都有适当的调试播放器。在运行时的非调试器版本中，Error.getStackTrace() 方法返回 null。