Android WebView的常用方法

来源：互联网发布：林弯弯淘宝店男装编辑：程序博客网时间：2024/05/03 10:02

Android app打开H5页一般要实现如下需求：

1、打开指定url网页；

2、点击链接可以跳转到下一页，并更新标题；

3、按back键或左箭头可以返回上一页；

4、当webview显示的是第一级url时，按返回键或左箭头关闭当前界面；

5、WebView如何传值给Android，例如使用H5登录成功后返回姓名、token等等字段。

6、支持JavaScript，支持显示JS对话框。

7、无网络时显示默认布局，以提高用户体验。

8、避免WebView的内存泄漏。

不多说，看下面代码如何实现上述功能。

参考布局：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:my="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="@color/activity_main_bg"    android:orientation="vertical">    <com.eloancn.borrower.common.widget.TitleView        android:id="@+id/titleView"        android:layout_width="match_parent"        android:layout_height="50dp"        my:titleText="H5" />    <RelativeLayout        android:id="@+id/rl_webViewContainer"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:orientation="vertical">        <!--在代码中添加webView防止内存泄露隐患-->        <LinearLayout            android:id="@+id/neterror_tip"            android:layout_width="match_parent"            android:layout_height="match_parent"            android:gravity="center_horizontal"            android:visibility="gone">            <ImageView                android:layout_marginTop="110dp"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:src="@drawable/not_found" />        </LinearLayout>    </RelativeLayout></LinearLayout>

示例代码：

public class CommonWebViewActivity extends Activity {    private WebView mWebView;    private TitleView mTitleView;    private RelativeLayout mWebViewContainer;    private String title;    private String url;    private LinearLayout neterrorLayout;    private int mFlag;   //来源    public static final int FLAG_SIGNATURE = 1;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_common_webview_main);        initData();        initView();        setData();    }    @Override    protected void onDestroy() {        super.onDestroy();        mWebView.setWebViewClient(null);        mWebView.setWebChromeClient(null);        mWebViewContainer.removeView(mWebView);        mWebView.removeAllViews();        mWebView.destroy();    }    private void initData() {        url = getIntent().getStringExtra("url");        title = getIntent().getStringExtra("title");        mFlag = getIntent().getIntExtra("flag", 0);    }    private void initView() {        mTitleView = (TitleView) findViewById(R.id.titleView);        mWebViewContainer = (RelativeLayout) findViewById(R.id.rl_webViewContainer);        neterrorLayout = (LinearLayout) findViewById(R.id.neterror_tip);        mWebView = new WebView(getApplicationContext());        LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(                LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);        mWebViewContainer.addView(mWebView, layoutParams);        WebSettings webSettings = mWebView.getSettings();        //设置WebView属性，能够执行Javascript脚本        webSettings.setJavaScriptEnabled(true);        //设置可以访问文件        webSettings.setAllowFileAccess(true);        //设置支持缩放        webSettings.setBuiltInZoomControls(false);        //允许js弹出窗口        webSettings.setJavaScriptCanOpenWindowsAutomatically(true);        mTitleView.setLeftBtnClickListener(new TitleView.OnBtnClickListener() {            @Override            public void onClick(View v) {                if (mWebView.canGoBack()) {                    mWebView.goBack();                } else {                    finish();                }            }        });    }    @Override    public boolean onKeyDown(int keyCode, KeyEvent event) {        if (keyCode == KeyEvent.KEYCODE_BACK) {            if (mWebView.canGoBack()) {                mWebView.goBack();                return true;            }        }        return super.onKeyDown(keyCode, event);    }    private void setData() {        mTitleView.setTitle(title);        mWebView.loadUrl(url);        mWebView.setWebChromeClient(new WebChromeClient(){            @Override            public boolean onJsAlert(WebView view, String url, final String message, final JsResult result) {                //注意，WebView默认不会显示JavaScript的Alert，需要Android实现。                runOnUiThread(new Runnable() {                    @Override                    public void run() {                        //自定义美观的Dialog，仅仅是为了显示message                       CustomDialog.Builder builder = new CustomDialog.Builder(CommonWebViewActivity.this);                        builder.setTitle("提示");                        builder.setMessage(message);                        builder.setSingle("知道了", new DialogInterface.OnClickListener() {                            @Override                            public void onClick(DialogInterface dialogInterface, int i) {                                dialogInterface.dismiss();                            }                        });                        builder.create().show();                    }                });                result.confirm();//这里必须调用，否则页面会阻塞造成假死                return true;            }            @Override            public void onReceivedTitle(final WebView view, final String title) {                super.onReceivedTitle(view, title);                if (FLAG_SIGNATURE == mFlag) {                    runOnUiThread(new Runnable() {                        @Override                        public void run() {                            mTitleView.setTitle(title);                        }                    });                }            }        });        mWebView.setWebViewClient(new WebViewClient() {            @Override            public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {                if (FLAG_SIGNATURE == mFlag) {                    Log.d("brycegao", "shouldInterceptRequest url:" + request.getUrl().toString());                    if (request.getUrl().toString().contains("wxd://getImage?tenderid=")) {                        //可以通过url传值给Android， 即在url里放置想要的参数                        runOnUiThread(new Runnable() {                            @Override                            public void run() {                                setResult(RESULT_OK);                                finish();                            }                        });                    }                }                return super.shouldInterceptRequest(view, request);            }            @Override            public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {                mWebView.loadUrl(url);                return true;            }            @Override            public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {                super.onReceivedError(view, request, error);                if (FLAG_SIGNATURE == mFlag                        && request.getUrl().toString().contains("wxd://getImage?tenderid=")) {                    //do nothing                    mWebView.setVisibility(View.GONE);  //优化体验，避免显示错误信息                } else {                    //加载失败                    neterrorLayout.setVisibility(View.VISIBLE);                    mWebView.setVisibility(View.GONE);                }            }        });        neterrorLayout.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                mWebView.setVisibility(View.VISIBLE);                neterrorLayout.setVisibility(View.GONE);                mWebView.loadUrl(url);            }        });    }}

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