2018-05-03 · 1 min read · #android#webview

WebView页面 软键盘弹出无法正确折叠页面的问题

问题出在webview页面 选中webview中edit控件弹出的软键盘 无法正确折叠页面 遮挡了输入框。一开始认为是webview的适配问题，想当然的加上了

<activity android:name=".WebViewActivity" android:windowSoftInputMode="adjustPan" >
...
</activity>

结果当然是毫！无！反！应！

在一番调试之后 发现时隐藏了状态栏之后 屏幕尺寸计算出现问题的缘故 也是个老google issue了

网上有很多解决办法 最通用的当然还是 原理很简单就是每当页面有变动的时候自行去计算页面高度- -

public class AndroidBug5497Workaround {
    public static void assistActivity(Activity activity) {
        new AndroidBug5497Workaround(activity);
    }

    private View mChildOfContent;
    private int usableHeightPrevious;
    private FrameLayout.LayoutParams frameLayoutParams;
    private int contentHeight;
    private boolean isfirst = true;
    private int statusBarHeight;

    private AndroidBug5497Workaround(Activity activity) {
        if (activity == null) {
            return;
        }
        //获取状态栏的高度
        int resourceId = activity.getResources().getIdentifier("status_bar_height", "dimen", "android");
        statusBarHeight = activity.getResources().getDimensionPixelSize(resourceId);
        FrameLayout content = activity.findViewById(android.R.id.content);
        mChildOfContent = content.getChildAt(0);

        //界面出现变动都会调用这个监听事件
        mChildOfContent.getViewTreeObserver().addOnGlobalLayoutListener(() -> {
            if (isfirst) {
                contentHeight = mChildOfContent.getHeight();//兼容华为等机型
                isfirst = false;
            }
            possiblyResizeChildOfContent();
        });

        frameLayoutParams = (FrameLayout.LayoutParams)
                mChildOfContent.getLayoutParams();
    }

    //重新调整跟布局的高度
    private void possiblyResizeChildOfContent() {

        int usableHeightNow = computeUsableHeight();

        //当前可见高度和上一次可见高度不一致 布局变动
        if (usableHeightNow != usableHeightPrevious) {
            //int usableHeightSansKeyboard2 = mChildOfContent.getHeight();//兼容华为等机型
            int usableHeightSansKeyboard = mChildOfContent.getRootView().getHeight();
            int heightDifference = usableHeightSansKeyboard - usableHeightNow;
            if (heightDifference > (usableHeightSansKeyboard / 4)) {
                // keyboard probably just became visible
                //frameLayoutParams.height = usableHeightSansKeyboard - heightDifference;
                frameLayoutParams.height = usableHeightSansKeyboard - heightDifference + statusBarHeight;
            } else {
                frameLayoutParams.height = contentHeight;
            }

            mChildOfContent.requestLayout();
            usableHeightPrevious = usableHeightNow;
        }
    }

    /**
     * 计算mChildOfContent可见高度     
     ** @return 高度
     */
    private int computeUsableHeight() {
        Rect r = new Rect();
        mChildOfContent.getWindowVisibleDisplayFrame(r);
        return (r.bottom - r.top);
    }
}