我有一个名为grayVal的变量，它告诉我相机所指向的像素的灰度值。显然，当我四处移动相机时，此数字一直在变化。我的问题是，当我在带有循环的异步中传递grayVal来测试grayVal通过阈值需要多长时间时，无论我将相机指向什么，该数字都不会改变。这是异步的限制，我需要执行其他解决方案吗？
public class startTestAsync extends AsyncTask<Integer, Void, Void> {
double[] timeArray = new double[500]; // set array
double rating = 0;
double lagStartTime;
double lagEndTime;
double lagTimeResult;
int testAmount;
int cnt;
@Override
protected Void doInBackground(Integer...grayVal) {
for (testAmount = 0; testAmount < 500; testAmount++) {
Log.i("Mat Value", String.valueOf(grayVal[0]));
lagStartTime = System.nanoTime();
while (grayVal[0] <= 100) {
lagEndTime = System.nanoTime();
lagTimeResult = (lagEndTime - lagStartTime);
timeArray[testAmount] = lagTimeResult;
}
return null;
}
protected void onPostExecute(Long result) {
}
ui线程
public void startTest (View view) {
new startTestAsync().execute(grayVal);
}
@Override
public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame) {
grayMat = inputFrame.gray();
double[] grayPixel = grayMat.get(100,100);
grayVal = (int)grayPixel[0];
Log.i("Mat Value", String.valueOf(grayVal));
return grayMat;
}
onCameraFrame logcat中的grayVal
08-25 08:28:56.576 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 50
08-25 08:28:56.639 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 37
08-25 08:28:56.703 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 52
08-25 08:28:56.769 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 53
08-25 08:28:56.835 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 50
08-25 08:28:56.903 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 48
08-25 08:28:56.971 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 47
08-25 08:28:57.038 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 49
08-25 08:28:57.103 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 46
08-25 08:28:57.172 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 46
08-25 08:28:57.240 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 43
08-25 08:28:57.302 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 41
08-25 08:28:57.368 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 44
08-25 08:28:57.436 14645-14989/bluemage.systems.displaylatencytester I/Mat Value﹕ 46
异步logcat中的grayVal
08-25 08:32:01.111 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.111 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.111 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.111 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.112 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.112 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.112 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.112 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.114 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.114 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.114 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.114 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.114 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.114 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
08-25 08:32:01.114 20759-21076/bluemage.systems.displaylatencytester I/Mat Value﹕ 133
均在logat中使用grayVal
08-25 09:02:49.170 6402-7189/bluemage.systems.displaylatencytester I/Mat Value Async﹕ 23
08-25 09:02:49.170 6402-7189/bluemage.systems.displaylatencytester I/Mat Value Async﹕ 23
08-25 09:02:49.170 6402-7189/bluemage.systems.displaylatencytester I/Mat Value Async﹕ 23
08-25 09:02:49.170 6402-6843/bluemage.systems.displaylatencytester I/Mat Value﹕ 22
08-25 09:02:49.170 6402-7189/bluemage.systems.displaylatencytester I/Mat Value Async﹕ 23
08-25 09:02:49.170 6402-7189/bluemage.systems.displaylatencytester I/Mat Value Async﹕ 23
最佳答案
grayVal(在doInBackground中)和grayVal(在onCameraFrame中)不同
因此，一个变量的变化不会影响另一变量。
即使没有完整的代码，也可以断定它们是不同的变量，因为它们具有不同的不兼容类型。grayVal(在doInBackground中)是一个数组，可以从以下代码推导得出:
Log.i("Mat Value", String.valueOf(grayVal[0]));
lagStartTime = System.nanoTime();
while (grayVal[0] <= 100) {
grayVal(在onCameraFrame中)是原始类型(或其包装类)，可以从以下代码推导得出:grayVal = (int)grayPixel[0];
关于java - 动态变量和异步，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/32203734/