Question

我正在尝试从webview中加载URL后包含的自定义javascript文件传递值。

我已经检查了这个reference但是当我加载除本地index.html文件之外的网站时它不起作用。

这是我创建Javacript界面的活动代码：

public class MainActivity extends AppCompatActivity {

    public static String URL = "https://www.ornativa.com";
    private WebView mWebView;
    private RelativeLayout mLoader;
    private Toolbar mToolbar;
    JSInterface JSI = new JSInterface(this);

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        createWebView();
    }

    @SuppressLint("SetJavaScriptEnabled")
    public void createWebView(){
        mWebView = (WebView)findViewById(
                R.id.webView);
        mToolbar = (Toolbar)findViewById(R.id.toolbar);

        mToolbar.setTitle(getResources().getString(R.string.app_name)+" | "+getResources().getString(R.string.app_name_hindi));
        mLoader = (RelativeLayout) findViewById(R.id.loader);
        // Add javascript support to the webview
        mWebView.getSettings().setJavaScriptEnabled(true);
        // Enable pinch zoom controls on webview
        mWebView.getSettings().setBuiltInZoomControls(false);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            if (0 != (getApplicationInfo().flags & ApplicationInfo.FLAG_DEBUGGABLE))
            { WebView.setWebContentsDebuggingEnabled(true); }
        }
        // Add a WebViewClient
        mWebView.setWebViewClient(new WebViewClient() {

            @Override
            public void onPageFinished(WebView view, String url) {

                // Inject CSS when page is done loading
                injectCSS();
                injectJS();
                super.onPageFinished(view, url);
                mLoader.setVisibility(View.GONE);
            }
        });

        mWebView.addJavascriptInterface(JSI, "Android");

        // Load a webpage
        mWebView.loadUrl(URL);
    }

    public void injectCSS(){
        try {
            InputStream inputStream = getAssets().open("styles.css");
            byte[] buffer = new byte[inputStream.available()];
            inputStream.read(buffer);
            inputStream.close();
            String encoded = Base64.encodeToString(buffer, Base64.NO_WRAP);
            mWebView.loadUrl("javascript:(function() {" +
                    "var parent = document.getElementsByTagName('head').item(0);" +
                    "var style = document.createElement('style');" +
                    "style.type = 'text/css';" +
                    // Tell the browser to BASE64-decode the string into your script !!!
                    "style.innerHTML = window.atob('" + encoded + "');" +
                    "parent.appendChild(style)" +
                    "})()");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void injectJS() {
        try {
            InputStream inputStream = getAssets().open("script.js");
            byte[] buffer = new byte[inputStream.available()];
            inputStream.read(buffer);
            inputStream.close();
            String encoded = Base64.encodeToString(buffer, Base64.NO_WRAP);
            mWebView.loadUrl("javascript:(function() {" +
                    "var parent = document.getElementsByTagName('head').item(0);" +
                    "var script = document.createElement('script');" +
                    "script.type = 'text/javascript';" +
                    "script.innerHTML = window.atob('" + encoded + "');" +
                    "parent.appendChild(script)" +
                    "})()");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onBackPressed() {
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setCancelable(false);
            builder.setIcon(R.mipmap.ic_launcher);
            builder.setTitle(R.string.app_name);
            builder.setMessage("Do you really want to Exit?");
            builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    //if user pressed "yes", then he is allowed to exit from application
                    finish();
                }
            });
            builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    //if user select "No", just cancel this dialog and continue with app
                    dialog.cancel();
                }
            });
            AlertDialog alert = builder.create();
            alert.show();

    }
    public class JSInterface {

        private Context mContext;

        public JSInterface(Context c) {
            mContext = c;

        }
        @JavascriptInterface
        public void showToast(String message) {
            Toast.makeText(mContext, message, Toast.LENGTH_LONG).show();
        }

    }


}

这是我的script.js文件：

document.getElementById("aadhaarNo").type= 'tel';
var myElem = document.getElementById('actionMessages');
Android.showToast("Hello World!");
if (myElem === null) {
    console.log('does not exist');
}
else{
    if (myElem.classList.contains('success')){
       console.log('success');
    }
}

我正在尝试从脚本文件调用该函数将值发送到Toast但Toast不会出现。

Answer 1

在JSInterface类中将“Context”更改为“Activity”。检查以下编辑的代码..

public class JSInterface {

        private Activity mContext;

        public JSInterface(Activity c) {
            mContext = c;

        }

        @JavascriptInterface
        public void showToast(String message) {
            Toast.makeText(mContext, message, Toast.LENGTH_LONG).show();
        }

    }

无法将Javascript文件中的值发送到Android Activity

1 个答案: