Android WebView 空白等待时加载动画

WebView 加载判断 和 加载动画的简单实现

WebView 在加载网页时候，在网络不好的情况下，如果不做处理会出现一段时间的等待空白，用户体验差。所以有必要加上一个简单的加载进度提示。本编简单的运用了ProgressDialog 这个控件来实现。

下面是简单的代码片段

 

<?xml version="1.0" encoding="utf-8"?>


    
        
        
    

    

下面贴上部分代码

 

public class FAQActivity extends BaseActivity {
    private final String TAG = FAQActivity.class.getName();
    @BindView(R.id.activity_fap_back)
    ImageView activityFapBack;
    @BindView(R.id.activity_faq_webview)
    WebView webView;
    private String FAQ_BASE_URL = "";


    /***
     *
     * @param savedInstanceState
     */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_faq);
        ButterKnife.bind(this);
        init();
    }

    private void init() {
        webView.loadUrl("你的请求地址");
        WebSettings mWebSettings = webView.getSettings();
        mWebSettings.setSupportZoom(true);
        mWebSettings.setLoadWithOverviewMode(true);
        mWebSettings.setUseWideViewPort(true);
        mWebSettings.setDefaultTextEncodingName("GBK");//设置解码格式
        mWebSettings.setLoadsImagesAutomatically(true);
        mWebSettings.setJavaScriptEnabled(true);//支持js 特效
        //覆盖WebView默认使用第三方或系统默认浏览器打开网页的行为，使网页用WebView打开
        webView.setWebViewClient(new WebViewClient() {
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                // TODO Auto-generated method stub
                //返回值是true的时候控制去WebView打开，为false调用系统浏览器或第三方浏览器
                view.loadUrl(url);
                return true;
            }

            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {
                super.onPageStarted(view, url, favicon);
                showProgress("页面加载中");//开始加载动画
            }

            @Override
            public void onPageFinished(WebView view, String url) {
                super.onPageFinished(view, url);
               removeProgress();//当加载结束时移除动画
            }
        });

    }

    /**
     * 点击事件
     */
    @OnClick(R.id.activity_fap_back)
    public void onClick() {
        Log.d(TAG, "onClick: ");
        jumpToActivity(FAQActivity.this,MenuActivity.class);
    }

    /**
     * 返回键的监听事件
     *
     * @param keyCode
     * @param event
     * @return
     */
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            jumpToActivity(FAQActivity.this,MenuActivity.class);
        }
        return false;
    }

}

需要注意的地方:

 

ProgressDIalog 控件为了不写重复代码，我进行了简单的封装。下面是我简单封装的BaseActivity代码

 

public class BaseActivity extends AppCompatActivity {
    private final String TAG = BaseActivity.class.getName();
    private Toast toast = null;
    private ProgressDialog progressDialog;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

    }

    /**
     * @param context 上下文对象
     * @param start   其实activity
     * @param target  目标activity
     */
    public void jumpToActivity(Context context, Class start, Class target) {
        Intent intent = new Intent(context, target);
        //------用户返回上一级activity
        if (target == CarFindingActivity.class) {
            intent.putExtra("activity", start);
        }
        context.startActivity(intent);
        finish();
    }

    public void jumpToActivity(Context context, Class target) {
        Intent intent = new Intent(context, target);
        //------用户返回上一级activity
        context.startActivity(intent);
        finish();
    }


    /**
     * @param context
     * @param text
     */
    public void showToastLong(Context context, String text) {
        if (toast == null) {
            toast = Toast.makeText(context, text, Toast.LENGTH_LONG);
        } else {
            toast.setText(text);
        }
        toast.show();
    }

    public void showToastLong(String text) {
        if (toast == null) {
            toast = Toast.makeText(BaseActivity.this, text, Toast.LENGTH_LONG);
        } else {
            toast.setText(text);
        }
        toast.show();
    }

    /**
     * @param context
     * @param text
     */
    public void showToastShort(Context context, String text) {
        if (toast == null) {
            toast = Toast.makeText(context, text, Toast.LENGTH_SHORT);
        } else {
            toast.setText(text);
        }
        toast.show();
    }

    public void showToastShort(String text) {
        if (toast == null) {
            toast = Toast.makeText(BaseActivity.this, text, Toast.LENGTH_SHORT);
        } else {
            toast.setText(text);
        }
        toast.show();
    }

    
    //-----显示ProgressDialog
    public void showProgress(String message) {
        if (progressDialog == null) {
            progressDialog = new ProgressDialog(BaseActivity.this, ProgressDialog.STYLE_SPINNER);
            progressDialog.setCancelable(false);//设置点击不消失
        }
        if (progressDialog.isShowing()) {
            progressDialog.setMessage(message);
        } else {
            progressDialog.setMessage(message);
            progressDialog.show();
        }
    }
    //------取消ProgressDialog
    public void removeProgress(){
        if (progressDialog==null){
           return;
        }
        if (progressDialog.isShowing()){
            progressDialog.dismiss();
        }

    }



    /**
     *
     */
    @Override
    protected void onStart() {
        super.onStart();

        Log.d(TAG, "onStart: ");
    }

    @Override
    protected void onResume() {
        super.onResume();
        Log.d(TAG, "onResume: ");
    }

    @Override
    protected void onPause() {
        super.onPause();
        Log.d(TAG, "onPause: ");
    }

    @Override
    protected void onStop() {
        removeProgress();//让progressdialog 消失
        super.onStop();
        Log.d(TAG, "onStop: ");
    }

    @Override
    protected void onRestart() {
        super.onRestart();
        Log.d(TAG, "onRestart: ");
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        Log.d(TAG, "onDestroy: ");
    }


}

 

然后继承BaseActivtiy 直接调用里面  

showProgress(String message)

显示ProgressDialog

 

 

removeProgress()

移除ProgressDialog

 

以上就这么多，如有错误或者不严谨的地方恳请指正,谢谢