java理解为什么在onDispatchTouchEvent()返回True后仍调用onClick()
比如说,在Android应用程序中,我们希望能够在任何时候暂时可靠地忽略所有用户触摸
根据我对堆栈溢出以及here、here和here所做的研究,一致同意的解决方案似乎是这样的:
(MainActivity.java的代码):
// returning true should mean touches are ignored/blocked
@Override
public boolean dispatchTouchEvent(MotionEvent pEvent) {
if (disableTouches) {
return true;
} else {
return super.dispatchTouchEvent(pEvent);
}
}
然而,当我们引入Android Monkey Exerciser Tool并以快速的速度向应用程序发送触摸事件时,很明显,猪开始在量子级别飞行——即使在“BlockTouchs”设置为true之后/期间,我们也可以接到对onClick()
的呼叫
我的问题是:这是为什么?——这是安卓的正常行为,还是我在代码中犯了错误?:)
注意:我已经排除了onClick()
被用户输入而不是触摸调用的可能性(因此不受onDispatchTouchEvent()
方法的控制)。。。通过在monkey命令中添加“-pct touch 100”
以下是我在测试中使用的代码:
主要活动:
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
View rootView; // turns black when "touch rejection" is in progress
View allowedButton;
View notAllowedButton;
// Used to decide whether to process touch events.
// Set true temporarily when notAllowedButton is clicked.
boolean touchRejectionAnimationInProgress = false;
int errorCount = 0; // counting "unexpected/impossible" click calls
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rootView = findViewById(R.id.rootView);
allowedButton = findViewById(R.id.allowedButton);
notAllowedButton = findViewById(R.id.notAllowedButton);
allowedButton.setOnClickListener(this);
notAllowedButton.setOnClickListener(this);
allowedButton.setBackgroundColor(Color.GREEN);
notAllowedButton.setBackgroundColor(Color.RED);
}
// returning true should mean touches are ignored/blocked
@Override
public boolean dispatchTouchEvent(MotionEvent pEvent) {
if (touchRejectionAnimationInProgress) {
Log.i("XXX", "touch rejected in dispatchTouchevent()");
return true;
} else {
return super.dispatchTouchEvent(pEvent);
}
}
@Override
public void onClick(View viewThatWasClicked){
Log.i("XXX", "onClick() called. View clicked: " + viewThatWasClicked.getTag());
//checking for unexpected/"impossible"(?) calls to this method
if (touchRejectionAnimationInProgress) {
Log.i("XXX!", "IMPOSSIBLE(?) call to onClick() detected.");
errorCount ++;
Log.i("XXX!", "Number of unexpected clicks: " + errorCount);
return;
} // else proceed...
if (viewThatWasClicked == allowedButton) {
// Irrelevant
} else if (viewThatWasClicked == notAllowedButton) {
// user did something that is not allowed.
touchRejectionAnimation();
}
}
// When the user clicks on something "illegal,"
// all user input is ignored temporarily for 200 ms.
// (arbitrary choice of duration, but smaller is better for testing)
private void touchRejectionAnimation() {
Log.i("XXX", "touchRejectionAnimation() called.");
touchRejectionAnimationInProgress = true;
rootView.setBackgroundColor(Color.BLACK);
// for logging/debugging purposes...
final String rejectionID = (new Random().nextInt() % 9999999) + "";
Log.i("XXX", "rejection : " + rejectionID + " started.");
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
try { Thread.sleep(200); } catch (Exception e) {
Log.e("XXX", "exception in touchRejection() BG thread!");
}
runOnUiThread(new Runnable() {
@Override
public void run() {
Log.i("XXX", "rejection " + rejectionID + " ending");
rootView.setBackgroundColor(Color.WHITE);
touchRejectionAnimationInProgress = false;
}
});
}
});
thread.start();
}
}
布局。xml:
<?xml version="1.0" encoding="utf-8"?>
<安卓.support.constraint.ConstraintLayout xmlns:安卓="http://schemas.安卓.com/apk/res/安卓"
xmlns:app="http://schemas.安卓.com/apk/res-auto"
xmlns:tools="http://schemas.安卓.com/tools"
安卓:id="@+id/rootView"
安卓:layout_width="match_parent"
安卓:layout_height="match_parent"
tools:context=".MainActivity">
<View
安卓:id="@+id/allowedButton"
安卓:layout_width="0dp"
安卓:layout_height="0dp"
安卓:layout_marginTop="32dp"
安卓:layout_marginBottom="32dp"
安卓:tag="allowedButton"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/notAllowedButton"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<View
安卓:id="@+id/notAllowedButton"
安卓:layout_width="0dp"
安卓:layout_height="0dp"
安卓:layout_marginTop="32dp"
安卓:layout_marginBottom="32dp"
安卓:tag="view2"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/allowedButton"
app:layout_constraintTop_toTopOf="parent" />
</安卓.support.constraint.ConstraintLayout>
# 1 楼答案
如果不想在任何视图上触发onClick(),请单击
以下是需要注意的步骤
注意:根据需要使用setViewsTouchable()方法,如果将参数传递为true,则所有视图都不可单击;如果为false,则视图都可单击