比方说，在 Android 应用中，我们希望能够在任何时候暂时可靠地忽略所有用户触摸。
根据我对堆栈溢出所做的研究以及 here , here , 和 here ，商定的解决方案似乎是这样的:
(MainActivity.java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);
}
}
但是，当我们引入 Android Monkey Exerciser Tool并快速将触摸事件发送到应用程序，很明显 pig 开始在量子级别飞翔——我们可以调用 onClick() 甚至在“blockTouches”之后/期间已设置为真。
我的问题是:这是为什么？ -- 这是正常的 Android 行为，还是我的代码有误？ :)
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() 控制) > 方法)...通过在 monkey 命令中添加“—-pct-touch 100”。
这是我用于此测试的代码:
主要 Activity :
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"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/rootView"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<View
android:id="@+id/allowedButton"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginTop="32dp"
android:layout_marginBottom="32dp"
android:tag="allowedButton"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/notAllowedButton"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<View
android:id="@+id/notAllowedButton"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginTop="32dp"
android:layout_marginBottom="32dp"
android:tag="view2"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/allowedButton"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
最佳答案
如果您不希望在任何 View 点击时触发您的 onClick()。
以下是需要注意的步骤。
Create custom viewGroup eg: MyConstraintLayout and add all child inside it.
Override onInterceptTouchEvent(MotionEvent ev) and return it has true.
public class MyConstraintLayout extends ConstraintLayout {
private boolean mIsViewsTouchable;
public ParentView(Context context) {
super(context);
}
public ParentView(Context context, AttributeSet attrs) {
super(context, attrs);
inflate(context, R.layout.custom_view, this);
}
public ParentView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
public void setViewsTouchable(boolean isViewTouchable) {
mIsViewsTouchable = isViewTouchable;
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
return mIsViewsTouchable;
}
}
注意:根据您的要求使用 setViewsTouchable() 方法，如果您将参数传递为 true，则所有 View 都不可点击，如果为 false，您的 View 将可点击。
关于java - 了解为什么即使在 onDispatchTouchEvent() 返回 True 后仍会调用 onClick()，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/52983232/