Android：让WebView支持<input type=”file”…>元素

Android：让WebView支持<input type=”file”…>元素 - GreatK

时间 2014-06-21 06:45:00  博客园-所有随笔区

原文  http://www.cnblogs.com/ilovewindy/p/3795111.html

主题 安卓开发

在Android中，当我们通过WebView打开一个页面时，如果里面有元素是<input type=”file”…>类型的，WebView只能正常的显示样式，但是是无法点击的。要解决这个问题，我们需要重写WebChromeClient。

下面直接给出Demo代码：

Activity文件：

public class MainActivity extends Activity {private final String host = "demo.com";private final String urlAddress = "http://" + host;private WebView web;private ProgressBar progressBar;private ValueCallback<Uri> mUploadMessage;private final static int FILECHOOSER_RESULTCODE = 1;@Overrideprotected void onActivityResult(int requestCode, int resultCode,Intent intent) {if (requestCode == FILECHOOSER_RESULTCODE) {if (null == mUploadMessage) return;Uri result = intent == null || resultCode != RESULT_OK ? null: intent.getData();mUploadMessage.onReceiveValue(result);mUploadMessage = null;}}/** * Called when the activity is first created. */@SuppressLint("SetJavaScriptEnabled")@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);web = (WebView) findViewById(R.id.webView1);progressBar = (ProgressBar) findViewById(R.id.progressBar1);WebSettings settings = web.getSettings();settings.setJavaScriptEnabled(true);web.loadUrl(urlAddress);web.setWebViewClient(new MyWebViewClient());web.setWebChromeClient(new WebChromeClient() {//关键代码，以下函数是没有API文档的，所以在Eclipse中会报错，如果添加了@Override关键字在这里的话。// For Android 3.0+public void openFileChooser(ValueCallback<Uri> uploadMsg) {mUploadMessage = uploadMsg;Intent i = new Intent(Intent.ACTION_GET_CONTENT);i.addCategory(Intent.CATEGORY_OPENABLE);i.setType("image/*");MainActivity.this.startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);}// For Android 3.0+public void openFileChooser(ValueCallback uploadMsg, String acceptType) {mUploadMessage = uploadMsg;Intent i = new Intent(Intent.ACTION_GET_CONTENT);i.addCategory(Intent.CATEGORY_OPENABLE);i.setType("*/*");MainActivity.this.startActivityForResult(Intent.createChooser(i, "File Browser"),FILECHOOSER_RESULTCODE);}//For Android 4.1public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {mUploadMessage = uploadMsg;Intent i = new Intent(Intent.ACTION_GET_CONTENT);i.addCategory(Intent.CATEGORY_OPENABLE);i.setType("image/*");MainActivity.this.startActivityForResult(Intent.createChooser(i, "File Chooser"), MainActivity.FILECHOOSER_RESULTCODE);}});//setContentView(web);}private class MyWebViewClient extends WebViewClient {@Overridepublic boolean shouldOverrideUrlLoading(WebView view, String url) {if (Uri.parse(url).getHost().equals(host)) {// This is my web site, so do not override; let my WebView load the pagereturn false;}// Otherwise, the link is not for a page on my site, so launch another Activity that handles URLsIntent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));startActivity(intent);return true;}@Overridepublic void onPageStarted(WebView view, String url, Bitmap favicon) {// TODO Auto-generated method stubsuper.onPageStarted(view, url, favicon);}@Overridepublic void onPageFinished(WebView view, String url) {// TODO Auto-generated method stubsuper.onPageFinished(view, url);progressBar.setVisibility(View.GONE);}}//flipscreen not loading again@Overridepublic void onConfigurationChanged(Configuration newConfig) {super.onConfigurationChanged(newConfig);}// 捕捉“回退”按键，让WebView能回退到上一页，而不是直接关闭Activity。@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {if ((keyCode == KeyEvent.KEYCODE_BACK) && web.canGoBack()) {web.goBack();return true;}return super.onKeyDown(keyCode, event);}}

Layout代码就不贴出来了，就是很简单的一个WebView和一个Progress。通过以上代码，我们就能够在WebView中上传文件了。

PS: 和iOS比起来，这不是一个完美的解决方案，因为它不支持直接拍照上传文件，如果需要这个功能的话，那么还需要做进一步的开发才行。