【项目中---WebView】Webview打开本地图片文件选择解决方案

Webview打开本地图片选择器解决方案

Webview打开本地图片选择器十分之麻烦，其在安卓系统3x 4x 5x上的行为都不同，处理也不同，所以之前差点崩溃。经过测试和完善，最终其在各个版本上都能完美工作，特此开源出来，希望能帮到大家

• Webview
• FileChooser
• 返回键处理
• Android3.0之前版本
• Android3.x版本
• Android4.x版本
• Android5.x版本

代码块

public class BrowserActivity extends BaseActivity {
    public ValueCallback mUploadMessage;
    public ValueCallback mUploadMessageForAndroid5;

    public final static int FILECHOOSER_RESULTCODE = 1;
    public final static int FILECHOOSER_RESULTCODE_FOR_ANDROID_5 = 2;



    @Bind(R.id.webview)
    WebView webView;

    @Bind(R.id.titleBar)
    View view;

    ProgressDialog progressBar;

    @Override
    protected void setRootView() {
        super.setRootView();
        setContentView(R.layout.activity_browser);
    }

    @Override
    protected void initData() {
        super.initData();
    }

    @Override
    protected void initWidget() {
        super.initWidget();

        progressBar = new ProgressDialog(this);
        progressBar.setProgressStyle(ProgressDialog.STYLE_SPINNER);

        webView.getSettings().setJavaScriptEnabled(true);
        webView.getSettings().setAppCacheEnabled(false);
        webView.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);

        webView.loadUrl(getIntent().getStringExtra(CommonKeys.url.name()));
        webView.setWebViewClient(new WebViewClient() {
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                //handler.sendEmptyMessage(0);
                view.loadUrl(url);
                return true;
            }
        });
        webView.setWebChromeClient(
                new WebChromeClient() {
                    public void onProgressChanged(WebView view, int progress) {// 载入进度改变而触发
                        if (progress == 100) {
                            //handler.sendEmptyMessage(1);// 如果全部载入,隐藏进度对话框
                        }

                        super.onProgressChanged(view, progress);
                    }

                    //扩展支持alert事件
                    @Override
                    public boolean onJsAlert(WebView view, String url, String message, JsResult result) {
                        AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());
                        builder.setTitle("xxx提示").setMessage(message).setPositiveButton("确定", null);
                        builder.setCancelable(false);
                        builder.setIcon(R.drawable.ic_launcher);
                        AlertDialog dialog = builder.create();
                        dialog.show();
                        result.confirm();
                        return true;
                    }

                    //扩展浏览器上传文件
                    //3.0++版本
                    public void openFileChooser(ValueCallback uploadMsg, String acceptType) {
                        openFileChooserImpl(uploadMsg);
                    }

                    //3.0--版本
                    public void openFileChooser(ValueCallback uploadMsg) {
                        openFileChooserImpl(uploadMsg);
                    }

                    public void openFileChooser(ValueCallback uploadMsg, String acceptType, String capture) {
                        openFileChooserImpl(uploadMsg);
                    }

                    // For Android > 5.0
                    public boolean onShowFileChooser (WebView webView, ValueCallback uploadMsg, WebChromeClient.FileChooserParams fileChooserParams) {
                        openFileChooserImplForAndroid5(uploadMsg);
                        return true;
                    }
                }
        );


        webView.addJavascriptInterface(new BrowserInterface(this), "BrowserInterface");
    }

    private void openFileChooserImpl(ValueCallback uploadMsg) {
        mUploadMessage = uploadMsg;
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
    }

    private void openFileChooserImplForAndroid5(ValueCallback uploadMsg) {
        mUploadMessageForAndroid5 = uploadMsg;
        Intent contentSelectionIntent = new Intent(Intent.ACTION_GET_CONTENT);
        contentSelectionIntent.addCategory(Intent.CATEGORY_OPENABLE);
        contentSelectionIntent.setType("image/*");

        Intent chooserIntent = new Intent(Intent.ACTION_CHOOSER);
        chooserIntent.putExtra(Intent.EXTRA_INTENT, contentSelectionIntent);
        chooserIntent.putExtra(Intent.EXTRA_TITLE, "Image Chooser");

        startActivityForResult(chooserIntent, FILECHOOSER_RESULTCODE_FOR_ANDROID_5);
    }

    @Override
    protected void initTopTitle() {
        view.setVisibility(View.GONE);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (webView.canGoBack() && event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
            //获取历史列表
            WebBackForwardList mWebBackForwardList = webView
                    .copyBackForwardList();
            //判断当前历史列表是否最顶端,其实canGoBack已经判断过
            if (mWebBackForwardList.getCurrentIndex() > 0) {
                webView.goBack();
                return true;
            }
        }
        return super.onKeyDown(keyCode, event);
    }

    @Override
    protected 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;

        } else if (requestCode == FILECHOOSER_RESULTCODE_FOR_ANDROID_5){
            if (null == mUploadMessageForAndroid5)
                return;
            Uri result = (intent == null || resultCode != RESULT_OK) ? null: intent.getData();
            if (result != null) {
                mUploadMessageForAndroid5.onReceiveValue(new Uri[]{result});
            } else {
                mUploadMessageForAndroid5.onReceiveValue(new Uri[]{});
            }
            mUploadMessageForAndroid5 = null;
        }
    }

    private Handler handler = new Handler() {
        public void handleMessage(Message msg) {// 定义一个Handler，用于处理下载线程与UI间通讯
            if (!Thread.currentThread().isInterrupted()){
                switch (msg.what) {
                    case 0:
                        progressBar.show();// 显示进度对话框
                        break;
                    case 1:
                        progressBar.hide();// 隐藏进度对话框，不可使用dismiss()、cancel(),否则再次调用show()时，显示的对话框小圆圈不会动。
                        break;
                }
            }

            super.handleMessage(msg);
        }
    };

}