简单心理 · 技术团队

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

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

String url = "https://www.google.com";
WebView webView = (WebView) findViewById(R.id.web_view);
webView.loadUrl(url);

<uses-permission android:name="android.permission.INTERNET"/>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent">

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

      <Button
          android:id="@+id/button"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_x="170dp"
          android:layout_y="400dp"
          android:background="@color/colorAccent"
          android:text="@string/app_name" />
  </WebView>
</LinearLayout>

Button button = (Button) findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        Toast.makeText(getApplicationContext(), "系好安全带!", Toast.LENGTH_SHORT).show();
    }
});

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String url = "https://www.google.com";
        WebView webView = (WebView) findViewById(R.id.web_view);
        webView.loadUrl(url);

        webView.setWebViewClient(new WebViewClient() {
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
                view.loadUrl(request.toString());
                return true;
            }
        });

        Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(getApplicationContext(), "系好安全带!", Toast.LENGTH_SHORT).show();
            }
        });
    }
}

rootLayout.removeView(webView);
webView.destroy();

if (webView.getContentHeight() * webView.getScale() == (webView.getHeight() + webView.getScrollY())) {
    //已经处于底端
}

if(webView.getScrollY() == 0){
    //处于顶端
}

  WebSettings webSettings = webView.getSettings();

  function readyToGo() {
      alert("Hello")
  }

  function alertMessage(message) {
      alert(message)
  }

  function getYourCar(){
      return "Car";
  }

String call = "javascript:readyToGo()";
webView.loadUrl(call);

String call = "javascript:alertMessage(\"" + "content" + "\")";
webView.loadUrl(call);

@TargetApi(Build.VERSION_CODES.KITKAT)
private void evaluateJavaScript(WebView webView){
    webView.evaluateJavascript("getYourCar()", new ValueCallback<String>() {
        @Override
        public void onReceiveValue(String s) {
            Log.d("findCar",s);
        }
    });
}

@JavascriptInterface
public void show(String s){
    Toast.makeText(getApplication(), s, Toast.LENGTH_SHORT).show();
}

webView.addJavascriptInterface(this, "android");

function toastClick(){
    window.android.show("JavaScript called~!");
}

@JavaInterface
public String getMessage(){
    return "Hello,boy~";
}

webView.addJavaScriptInterface(this,"Android");

function showHello(){
    var str=window.Android.getMessage();
    console.log(str);
}

WebSettings settings = webView.getSettings();
settings.setAppCacheEnabled(true);
settings.setDatabaseEnabled(true);
settings.setDomStorageEnabled(true);//开启DOM缓存
settings.setCacheMode(WebSettings.LOAD_DEFAULT);

ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
if(networkInfo.isAvailable()) {
    settings.setCacheMode(WebSettings.LOAD_DEFAULT);//网络正常时使用默认缓存策略
} else {
    settings.setCacheMode(WebSettings.LOAD_CACHE_ONLY);//网络不可用时只使用缓存
}

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

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:theme="@style/ThemeOverlay.AppCompat.Light" />

    </android.support.design.widget.AppBarLayout>

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

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

        <ProgressBar
            android:id="@+id/progress_bar"
            android:layout_width="50dp"
            android:layout_height="50dp"
            android:layout_gravity="center"
            android:visibility="gone" />
    </FrameLayout>
</LinearLayout>

public class MainActivity extends AppCompatActivity {

  private WebView mWebView;

  private ProgressBar mProgressbar;
  private Toolbar mToolbar;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
      supportRequestWindowFeature(Window.FEATURE_NO_TITLE);
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);

      initAppBar();//初始化Toolbar

      initWebView();//初始化WebView
      initWebSettings();//初始化WebSettings
      initWebViewClient();//初始化WebViewClient
      initWebChromeClient();//初始化WebChromeClient
  }

  private void initAppBar() {
      mToolbar = (Toolbar) findViewById(R.id.toolbar);
      mToolbar.setTitle("载入中..");
      mToolbar.setTitleTextColor(getResources().getColor(R.color.colorWhite));
      setSupportActionBar(mToolbar);
      getSupportActionBar().setDisplayHomeAsUpEnabled(false);
  }

  private void initWebView() {
      mWebView = (WebView) findViewById(R.id.web_view);
      mProgressbar = (ProgressBar) findViewById(R.id.progress_bar);
      String url = "https://www.google.com";
      mWebView.loadUrl(url);
  }

  private void initWebSettings() {
      WebSettings settings = mWebView.getSettings();
      //支持获取手势焦点
      mWebView.requestFocusFromTouch();
      //支持JS
      settings.setJavaScriptEnabled(true);
      //支持插件
      settings.setPluginState(WebSettings.PluginState.ON);
      //设置适应屏幕
      settings.setUseWideViewPort(true);
      settings.setLoadWithOverviewMode(true);
      //支持缩放
      settings.setSupportZoom(false);
      //隐藏原生的缩放控件
      settings.setDisplayZoomControls(false);
      //支持内容重新布局
      settings.setLayoutAlgorithm(WebSettings.LayoutAlgorithm.SINGLE_COLUMN);
      settings.supportMultipleWindows();
      settings.setSupportMultipleWindows(true);
      //设置缓存模式
      settings.setDomStorageEnabled(true);
      settings.setDatabaseEnabled(true);
      settings.setCacheMode(WebSettings.LOAD_DEFAULT);
      settings.setAppCacheEnabled(true);
      settings.setAppCachePath(mWebView.getContext().getCacheDir().getAbsolutePath());

      //设置可访问文件
      settings.setAllowFileAccess(true);
      //当webview调用requestFocus时为webview设置节点
      settings.setNeedInitialFocus(true);
      //支持自动加载图片
      if (Build.VERSION.SDK_INT >= 19) {
          settings.setLoadsImagesAutomatically(true);
      } else {
          settings.setLoadsImagesAutomatically(false);
      }
      settings.setNeedInitialFocus(true);
      //设置编码格式
      settings.setDefaultTextEncodingName("UTF-8");
  }

  private void initWebViewClient() {
      mWebView.setWebViewClient(new WebViewClient() {

          //页面开始加载时
          @Override
          public void onPageStarted(WebView view, String url, Bitmap favicon) {
              super.onPageStarted(view, url, favicon);
              mProgressbar.setVisibility(View.VISIBLE);
          }


          //页面完成加载时
          @Override
          public void onPageFinished(WebView view, String url) {
              super.onPageFinished(view, url);
              mProgressbar.setVisibility(View.GONE);
          }

          //是否在WebView内加载新页面
          @Override
          public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
              view.loadUrl(request.toString());
              return true;
          }

          //网络错误时回调的方法
          @Override
          public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
              super.onReceivedError(view, request, error);
              /**
               * 在这里写网络错误时的逻辑,比如显示一个错误页面
               *
               * 这里我偷个懒不写了
               * */
          }

          @TargetApi(Build.VERSION_CODES.M)
          @Override
          public void onReceivedHttpError(WebView view, WebResourceRequest request, WebResourceResponse errorResponse) {
              super.onReceivedHttpError(view, request, errorResponse);
          }
      });
  }

  private void initWebChromeClient() {

      mWebView.setWebChromeClient(new WebChromeClient() {

          private Bitmap mDefaultVideoPoster;//默认的视频展示图

          @Override
          public void onReceivedTitle(WebView view, String title) {
              super.onReceivedTitle(view, title);
              setToolbarTitle(title);
          }

          @Override
          public Bitmap getDefaultVideoPoster() {
              if (mDefaultVideoPoster == null) {
                  mDefaultVideoPoster = BitmapFactory.decodeResource(
                          getResources(), R.drawable.video_default
                  );
                  return mDefaultVideoPoster;
              }
              return super.getDefaultVideoPoster();
          }
      });
  }

  /**
   * 设置Toolbar标题
   *
   * @param title
   */
  private void setToolbarTitle(final String title) {
      Log.d("setToolbarTitle", " WebDetailActivity " + title);
      if (mToolbar != null) {
          mToolbar.post(new Runnable() {
              @Override
              public void run() {
                  mToolbar.setTitle(TextUtils.isEmpty(title) ? getString(R.string.loading) : title);
              }
          });
      }
  }

  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
      getMenuInflater().inflate(R.menu.menu_main, menu);
      return super.onCreateOptionsMenu(menu);
  }

  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
      switch (item.getItemId()) {
          case R.id.page_up:
              Toast.makeText(getApplicationContext(), "页面向上", Toast.LENGTH_SHORT).show();
              mWebView.pageUp(true);
              break;
          case R.id.page_down:
              Toast.makeText(getApplicationContext(), "页面向下", Toast.LENGTH_SHORT).show();
              mWebView.pageDown(true);
              break;
          case R.id.refresh:
              Toast.makeText(getApplicationContext(), "刷新~", Toast.LENGTH_SHORT).show();
              mWebView.reload();
          default:
              return super.onOptionsItemSelected(item);
      }
      return super.onOptionsItemSelected(item);
  }

  @Override
  public boolean onKeyDown(int keyCode, KeyEvent event) {

      //如果按下的是回退键且历史记录里确实还有页面
      if ((keyCode == KeyEvent.KEYCODE_BACK) && mWebView.canGoBack()) {
          mWebView.goBack();
          return true;
      } else {
          Toast.makeText(getApplicationContext(), "考试结束,恭喜您考试合格!", Toast.LENGTH_LONG).show();
      }
      return super.onKeyDown(keyCode, event);
  }
}