Android app freezes when app soft keyboard is displayed or hide

问题

I have an activity which has a fragment. Inside that fragment, there are 5 fragmnets inside ViewPager. Each fragment has either more than 30 input fields including EditTexts, custom Dropdowns and Date Pickers or nested ViewPagers with fragments having same amount of input fields. The problem is; when user taps on any EditText to input data, soft keyboard gets visible and when it is completely visible, the app freezes for around 2 seconds. When user presses back button to hide soft keyboard, keyboard gets off from screen and screen area which is underneath soft keyboard becomes white and app freezes again for same amount of time. This happens every time. Here is activity configuration from manifest:

 <activity
        android:name=".activities.HomeActivity"
        android:launchMode="singleTask"
        android:screenOrientation="portrait"
        android:windowSoftInputMode="adjustPan|adjustResize" />

I have tried different combinations for android:windowSoftInputMode nothing worked. Although this does not happen in other activities with same manifest configuration and with less number of fields. With so many input fields, its very annoying for user that app freezes after inputting data in textfields. Can anyone suggest me workaround for this?

回答1:

I will need to hands-on debug to find the issue, but what I think I will do is:

1. Check whether this is actually because of those many fragments and input controls.
   Can you try with only 1 fragment instead of 5 fragments and see if the speed improves?
   If yes, then try to display a fragment at once (ex: if you change from tab 1 to tab 2, explicitly remove fragment 1 from the pager view hierarchy and explicitly add fragment 2 to the pager view hierarchy). If after you simplify your controls, you still see the freeze, then that might not be because of too many controls.

2. Check whether there is offending control(s).
   Maybe you have a control or two that unexpectedly do a routine that heavily taxed your resources. If from point #1 you can find a fragment that significantly slowing down your app when it gets displayed, you might want to check further into that fragment and controls inside.

回答2:

I have found the solution. In most of the layouts, the views were aligned vertical to each other inside RelativeLayout using android:layout_below property like:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:id="@+id/layout1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <!--nested form view containers-->

        </LinearLayout>

    </LinearLayout>

    <LinearLayout
        android:id="@+id/layout2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/layout1"
        android:orientation="vertical">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <!--nested form view containers-->

        </LinearLayout>

    </LinearLayout>

    <LinearLayout
        android:id="@+id/layout3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/layout2"
        android:orientation="vertical">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <!--nested form view containers-->

        </RelativeLayout>

    </LinearLayout>

</RelativeLayout>

I replaced root RelativeLayouts with vertical oriented LinearLayouts and it did the magic trick like this:

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:id="@+id/layout1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <!--nested form view containers-->

        </LinearLayout>

    </LinearLayout>

    <LinearLayout
        android:id="@+id/layout2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <!--nested form view containers-->

        </LinearLayout>

    </LinearLayout>

    <LinearLayout
        android:id="@+id/layout3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <!--nested form view containers-->

        </RelativeLayout>

    </LinearLayout>

</LinearLayout>

I am still looking for some technical details on how it impacts keyboard visibility states. Will update here if I find something.

来源：https://stackoverflow.com/questions/57507527/android-app-freezes-when-app-soft-keyboard-is-displayed-or-hide