Question

每当我输入该片段时，都会在空白处显示几秒钟，然后显示WebView中的网页。似乎没有显示ProgressBar。

这是我的WebView和ProgressBar所在片段的XML文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context=".FragmentThree">

    <ProgressBar

        android:id="@+id/progressbar"
        style="@style/Widget.AppCompat.ProgressBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_centerVertical="true"/>

    <WebView
        android:id="@+id/webview"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </WebView>

</RelativeLayout>

这是Fragment Java实现的Java文件：

package com.example.task1;

import android.content.Context;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;

import androidx.fragment.app.Fragment;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;


public class FragmentThree extends Fragment {
    private WebView webView;
    private String URL;
    private ProgressBar progressBar;

    private OnFragmentInteractionListener mListener;

    public FragmentThree(String url) {
        // Required empty public constructor
        this.URL = url;
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view =  inflater.inflate(R.layout.fragment_three, container, false);
        initMain(view);
        return view;
    }

    private void initMain(View view) {
        webView = view.findViewById(R.id.webview);
        progressBar = view.findViewById(R.id.progressbar);

        progressBar.setMax(100);
        webView.loadUrl(URL);
        webView.setWebViewClient(new WebViewClient());
        webView.setWebChromeClient(new WebChromeClient(){
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                progressBar.setProgress(newProgress);
            }
        });

    }

    // TODO: Rename method, update argument and hook method into UI event
    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);
        }
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnFragmentInteractionListener) {
            mListener = (OnFragmentInteractionListener) context;
        } else {
            throw new RuntimeException(context.toString()
                    + " must implement OnFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    public interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        void onFragmentInteraction(Uri uri);
    }
}

代码大部分位于initMain（）函数下，以进行澄清。

任何建议都将不胜感激，谢谢阅读！

Answer 1

只需在ProgressBar下面声明Webview

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context=".FragmentThree">



    <WebView
        android:id="@+id/webview"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </WebView>
    <ProgressBar

        android:id="@+id/progressbar"
        style="@style/Widget.AppCompat.ProgressBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"/>
</RelativeLayout>

ProgressBar不会出现在Fragment

1 个答案: