沉浸式状态栏用了一段时间了，一直没发现安卓在这方面的坑。最近在集成环信自定义UI的过程中，发现将环信界面设置为沉浸式之后最底部的消息输入框不随键盘弹起而变化了，一直显示在屏幕最下方，体验非常差。
后来测试发现只要使用去除状态栏的主题如：Theme.AppCompat.Light.NoActionBar这种就会出现上述现象。
经过一个小时的百度与测试，终于找到一个最简洁的解决方法，只需要在Activity中调用一个工具类传入this即可，无需其他设置，下面分享下工具类：
public class SoftHideKeyBoardUtil {
private static final String TAG = "SoftHideKeyBoardUtil";
public static void assistActivity(View activity) {
new SoftHideKeyBoardUtil(activity);
}
public static void assistActivity(Activity activity) {
new SoftHideKeyBoardUtil(activity);
}
private final View mChildOfContent;
private int usableHeightPrevious;
private final FrameLayout.LayoutParams frameLayoutParams;
//为适应华为小米等手机键盘上方出现黑条或不适配
private int contentHeight;//获取setContentView本来view的高度
private boolean isfirst = true;//只用获取一次
private int statusBarHeight;//状态栏高度
private SoftHideKeyBoardUtil(View fr) {
//2､获取到setContentView放进去的View
mChildOfContent = fr;
//3､给Activity的xml布局设置View树监听，当布局有变化，如键盘弹出或收起时，都会回调此监听
//4､软键盘弹起会使GlobalLayout发生变化
mChildOfContent.getViewTreeObserver().addOnGlobalLayoutListener(() -> {
if (isfirst) {
contentHeight = mChildOfContent.getHeight();//兼容华为等机型
if (BuildConfig.CUT_DEBUG)
Log.d("SoftHideKeyBoardUtil", "SoftHideKeyBoardUtil: contentHeight = " + contentHeight);
isfirst = false;
}
//5､当前布局发生变化时，对Activity的xml布局进行重绘
possiblyResizeChildOfContent();
});
//6､获取到Activity的xml布局的放置参数
ViewGroup.LayoutParams vl = mChildOfContent.getLayoutParams();
frameLayoutParams = (FrameLayout.LayoutParams) vl;
}
private SoftHideKeyBoardUtil(Activity activity) {
//1､找到Activity的最外层布局控件，它其实是一个DecorView,它所用的控件就是FrameLayout
FrameLayout content = activity.findViewById(android.R.id.content);
//2､获取到setContentView放进去的View
mChildOfContent = content.getChildAt(0);
//3､给Activity的xml布局设置View树监听，当布局有变化，如键盘弹出或收起时，都会回调此监听
//4､软键盘弹起会使GlobalLayout发生变化
mChildOfContent.getViewTreeObserver().addOnGlobalLayoutListener(() -> {
if (isfirst) {
contentHeight = mChildOfContent.getHeight();//兼容华为等机型
isfirst = false;
}
//5､当前布局发生变化时，对Activity的xml布局进行重绘
possiblyResizeChildOfContent();
});
//6､获取到Activity的xml布局的放置参数
frameLayoutParams = (FrameLayout.LayoutParams) mChildOfContent.getLayoutParams();
}
// 获取界面可用高度，如果软键盘弹起后，Activity的xml布局可用高度需要减去键盘高度
private void possiblyResizeChildOfContent() {
//1､获取当前界面可用高度，键盘弹起后，当前界面可用布局会减少键盘的高度
int usableHeightNow = computeUsableHeight();
if (BuildConfig.CUT_DEBUG)
Log.d(TAG, "possiblyResizeChildOfContent: 键盘弹起后，当前界面可用布局会减少键盘的高度 = " + usableHeightNow);
//2､如果当前可用高度和原始值不一样
if (usableHeightNow != usableHeightPrevious) {
//3､获取Activity中xml中布局在当前界面显示的高度
int usableHeightSansKeyboard = mChildOfContent.getRootView().getHeight();
if (BuildConfig.CUT_DEBUG)
Log.d(TAG, "possiblyResizeChildOfContent: Activity中xml中布局在当前界面显示的高度 = " + usableHeightSansKeyboard);
//4､Activity中xml布局的高度-当前可用高度
int heightDifference = usableHeightSansKeyboard - usableHeightNow;
if (BuildConfig.CUT_DEBUG)
Log.d(TAG, "possiblyResizeChildOfContent: Activity中xml布局的高度 - 当前可用高度 = " + heightDifference);
//5､高度差大于屏幕1/4时，说明键盘弹出
if (heightDifference > (usableHeightSansKeyboard / 4)) {
// 6､键盘弹出了，Activity的xml布局高度应当减去键盘高度
frameLayoutParams.height = usableHeightSansKeyboard - heightDifference + statusBarHeight;
} else {
frameLayoutParams.height = contentHeight;
}
if (BuildConfig.CUT_DEBUG)
Log.d(TAG, "possiblyResizeChildOfContent: frameLayoutParams.height = " + frameLayoutParams.height);
//7､ 重绘Activity的xml布局
mChildOfContent.requestLayout();
usableHeightPrevious = usableHeightNow;
}
}
private int computeUsableHeight() {
Rect r = new Rect();
mChildOfContent.getWindowVisibleDisplayFrame(r);
// 全屏模式下：直接返回r.bottom，r.top其实是状态栏的高度
return (r.bottom - r.top);
}
}
使用方法：
activity 的onCreate() 中设置
SoftHideKeyBoardUtil.assistActivity(this);
