webview adjustResize處理類(包含了沉浸式狀態欄以及虛擬按鍵等狀況的適配設置)

看見網上一堆沒有處理沉浸式狀態欄以及虛擬按鍵的錯誤處理類，這裏給出我實踐過的代碼

package com.zjw.apporder;

import android.app.Activity;
import android.view.View;
import android.view.ViewTreeObserver;
import android.widget.FrameLayout;

/**
 * 正確解決webview不能adjustResize的處理類(包含了沉浸式狀態欄以及虛擬按鍵等狀況的適配設置)
 */
public class AndroidBug5497Workaround {
    public static void assistActivity(Activity activity) {
        new AndroidBug5497Workaround(activity);
    }

    private View mChildOfContent;
    private int usableHeightPrevious;
    private FrameLayout.LayoutParams frameLayoutParams;
    private Activity activity;
    private int statusBarHeight;

    private AndroidBug5497Workaround(Activity activity) {
        //獲取狀態欄的高度
        int resourceId = activity.getResources().getIdentifier("status_bar_height", "dimen", "android");
        statusBarHeight = activity.getResources().getDimensionPixelSize(resourceId);
        this.activity = activity;
        FrameLayout content = (FrameLayout) activity.findViewById(android.R.id.content);
        mChildOfContent = content.getChildAt(0);

        //界面出現變更都會調用這個監聽事件
        mChildOfContent.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            public void onGlobalLayout() {
                possiblyResizeChildOfContent();
            }
        });

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

    private boolean mIsFirstResize = true;
    private int mChildOfContentSize = 0;
    private int usableHeightNow;

    private void possiblyResizeChildOfContent() {
        //錯誤作法拿到usableHeightNow
        // int usableHeightNow = computeUsableHeight();
        if (mIsFirstResize) {
            //保留原來系統默認算好的mChildOfContent高度(根據flag和系統狀態欄和下面虛擬按鍵和諧相處的正確值)
            mChildOfContentSize = mChildOfContent.getHeight();
            mIsFirstResize = false;
        }
        usableHeightNow = mChildOfContent.getHeight();
        if (usableHeightNow != usableHeightPrevious) {
            int usableHeightSansKeyboard = mChildOfContent.getRootView().getHeight();
            int heightDifference = usableHeightSansKeyboard - usableHeightNow;
            if (heightDifference > (usableHeightSansKeyboard / 4)) {
                // keyboard probably just became visible
                frameLayoutParams.height = usableHeightSansKeyboard - heightDifference;
            } else {
                // keyboard probably just became hidden
                //這裏不能單純使用frameLayoutParams.height = computeUsableHeight();  由於usableHeightNow和一些flag有關，網上frameLayoutParams.height = usableHeightSansKeyboard 直接就錯了，由於usableHeightSansKeyboard恆爲全屏高度
                //1.當使用 window.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN) 全屏時getWindowVisibleDisplayFrame高度爲全屏(系統狀態欄和下面虛擬按鍵呼出懸浮在上面)
                //2.當使用FLAG_TRANSLUCENT_STATUS 的時候getWindowVisibleDisplayFrame拿到的是不包含系統狀態欄的高度可是又頂上了系統欄的位置，致使出錯
                //綜合上述幾點正確作法爲當前代碼實現,即便用系統默認算好的mChildOfContent高度，當鍵盤喚起，保留當前mChildOfContent高度，鍵盤消失再設置回去
                frameLayoutParams.height = mChildOfContentSize;
            }
            mChildOfContent.requestLayout();
            usableHeightPrevious = frameLayoutParams.height;
        }
    }

    /**
     * 計算mChildOfContent可見高度     ** @return
     */
   /* private int computeUsableHeight() {
        Rect r = new Rect();
        mChildOfContent.getWindowVisibleDisplayFrame(r);
        return (r.bottom - r.top);
    }
*/
}
複製代碼