Flex(flash)检测摄像头的3种状态(是否被占用,没安装摄像头,正常)

在视频程序的编写过程中，我们经常要使用摄像头，在使用摄像头前有必要对摄像头的现有状态做个检测:

1.被占用

2.没安装摄像头

3.正常

camera=Camera.getCamera();
               if (camera == null)
                {
                   if (Camera.names.length <= 0)
                    { 
                        
                        Alert.show("没安装摄像头");
                    }
                }
                else
                {
                    this.vdpaly.attachCamera(this.camera);
                    this.isCameraBusy();
                }

private function isCameraBusy():void
            {
                this.intervalId=setInterval(callback,50);
            }

private function callback():void

{

trace("currentFPS=" + camera.currentFPS.toString());

if (camera.currentFPS > 0)

{                     //视频设备可用

clearInterval(this.intervalId);

this.isBusyCamera=false;

Alert.show("摄像头正常");

}

else

{

times++;

trace("times=" + times.toString());

if (times > 30)

{                         //视频设备忙

clearInterval(intervalId);

this.isBusyCamera=true;

Alert.show("摄像头被占用");

}

}

}

代码说明：

camera == null，那么就是没安装摄像头

如果摄像头被占用，那么camera.currentFPS 肯定不会大 于0,而是等于0