Question

我尝试了很多方法，但是我不想要做的就是在加载网页时显示进度栏请帮我这是我的代码 MainActivity.Java

package com.krishnakingofrestoration.progress;

 import android.app.Activity;
 import android.graphics.Bitmap;
 import android.os.Bundle;
 import android.view.View;
 import android.webkit.WebView;
 import android.widget.ProgressBar;


 public class MainActivity extends Activity {

WebView webview;
ProgressBar pbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    webview = (WebView)findViewById(R.id.webview);
    pbar = (ProgressBar)findViewById(R.id.progressBar2);
    webview.setWebViewClient(new WebViewClient());
    webview.loadUrl("http://www.google.com");
}

public class WebViewClient extends android.webkit.WebViewClient
{
    @Override
    public void onPageStarted(WebView view, String url, Bitmap favicon) {

        // TODO Auto-generated method stub
        super.onPageStarted(view, url, favicon);
    }

    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {

        // TODO Auto-generated method stub
        view.loadUrl(url);
        return true;
    }
    @Override
    public void onPageFinished(WebView view, String url) {

        // TODO Auto-generated method stub

        super.onPageFinished(view, url);
        pbar.setVisibility(View.GONE);

    }

}

@Override
public void onBackPressed() {
    if (webview.canGoBack()){
        webview.goBack();
    }
    else {
        super.onBackPressed();
    }
}

activity_main.xml

      <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"
  tools:context=".MainActivity" >

<ProgressBar
    android:id="@+id/progressBar2"
    style="?android:attr/progressBarStyle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="217dp" />

<WebView
    android:id="@+id/webview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="0dp" />
  </RelativeLayout>

我无法使用 Android Studio 3.2.1 和Android Marshmallow 6.0，请帮帮我Gradle 4.1.2 它是我的完整代码，我想您会帮助我我想要圈子进度栏，请给我正确答案

Answer 1

您的ProgressBar当前隐藏在您的WebView下。只需更改.xml文件中的顺序

Answer 2

首先像下面的代码那样在xml中交换WebView和ProgressBar的顺序：

<?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"
tools:context=".MainActivity" >

   <WebView
    android:id="@+id/webview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="0dp" />
   <ProgressBar
    android:id="@+id/progressBar2"
    style="?android:attr/progressBarStyle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="217dp"/>
</RelativeLayout>

Java文件中的代码

public class MainActivity extends AppCompatActivity {
WebView webview;
ProgressBar pbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    webview = findViewById(R.id.webview);
    pbar = findViewById(R.id.progressBar2);
    webview.setWebViewClient(new WebViewClient() {
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            super.onPageStarted(view, url, favicon);
            pbar.setVisibility(View.VISIBLE);
        }
        public void onPageFinished(WebView view, String url) {

            super.onPageFinished(view, url);
            pbar.setVisibility(View.GONE);
        }
        public void onReceivedError(WebView view, int errorCode,
                                    String description, String failingUrl) {
            super.onReceivedError(view, errorCode, description, failingUrl);
            Toast.makeText(MainActivity.this,
                    "The Requested Page Does Not Exist", Toast.LENGTH_LONG).show();
            webview.loadUrl("https://www.google.com");
        }
    });
    webview.loadUrl("https://www.google.com");
    webview.getSettings().setLoadWithOverviewMode(true);
    webview.getSettings().setUseWideViewPort(true);
    webview.getSettings().setJavaScriptEnabled(true);
}
@Override
public void onBackPressed() {
    if (webview.canGoBack()){
        webview.goBack();
    }
    else {
        super.onBackPressed();
    }
  }
}

我希望它对您有用。

如何在WebView Android中创建Progresbar

2 个答案: