Android记录6--WebView相关小知识

webview无法展示alert

解决办法：

mWebView.setWebChromeClient(new WebChromeClient());

Android webview支持获取本地图片或拍照

注意：Android6.0以上需要首先获取摄像头权限，不然无法获取照片

package com.wshoto.user.anyong.ui.activity;

public class BBSActivity extends InitActivity {

    @BindView(R.id.wv_bbs)
    WebView mWvBbs;
    private ValueCallback<Uri> mUploadMessage;// 表单的数据信息
    private ValueCallback<Uri[]> mUploadCallbackAboveL;
    private final static int FILECHOOSER_RESULTCODE = 1;// 表单的结果回调
    private Uri imageUri;

    @Override
    public void initView(Bundle savedInstanceState) {
        setContentView(R.layout.activity_bbs);
        ButterKnife.bind(this);
        init();
    }

    @Override
    public void initData() {
        mWvBbs.loadUrl("https://xxx");
    }


    private void init() {
        WebSettings webSettings = mWvBbs.getSettings();
        webSettings.setUseWideViewPort(true);//设置此属性，可任意比例缩放
        webSettings.setRenderPriority(WebSettings.RenderPriority.HIGH);

        webSettings.setUseWideViewPort(true);
        webSettings.setLoadWithOverviewMode(true);
        webSettings.setJavaScriptEnabled(true);
        webSettings.setAppCacheMaxSize(1024 * 1024 * 8);
        String appCachePath = getApplicationContext().getCacheDir().getAbsolutePath();
        webSettings.setAppCachePath(appCachePath);
        webSettings.setAllowFileAccess(true);
        webSettings.setSupportZoom(true);
        webSettings.setJavaScriptCanOpenWindowsAutomatically(true);
        webSettings.setTextSize(WebSettings.TextSize.NORMAL);

        mWvBbs.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);
        //open dom storage
        webSettings.setDomStorageEnabled(true);
        //priority high
        webSettings.setRenderPriority(WebSettings.RenderPriority.HIGH);
        webSettings.setAppCacheEnabled(true);
        webSettings.setDatabaseEnabled(true);
        webSettings.setDatabasePath(BBSActivity.this.getApplicationContext().getCacheDir().getAbsolutePath());
        //add by wjj end
        String ua = webSettings.getUserAgentString();
        mWvBbs.setWebChromeClient(new WebChromeClient() {

            @Override
            public boolean onShowFileChooser(WebView webView,
                                             ValueCallback<Uri[]> filePathCallback,
                                             FileChooserParams fileChooserParams) {
                mUploadCallbackAboveL = filePathCallback;
                take();
                return true;
            }


            public void openFileChooser(ValueCallback<Uri> uploadMsg) {
                mUploadMessage = uploadMsg;
                take();
            }

            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType) {
                mUploadMessage = uploadMsg;
                take();
            }

            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
                mUploadMessage = uploadMsg;
                take();
            }
        });
        mWvBbs.setWebViewClient(new WebViewClient() {

            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                //该方法在Build.VERSION_CODES.LOLLIPOP以前有效，从Build.VERSION_CODES.LOLLIPOP起，建议使用shouldOverrideUrlLoading(WebView, WebResourceRequest)} instead
                //返回false，意味着请求过程里，不管有多少次的跳转请求（即新的请求地址），均交给webView自己处理，这也是此方法的默认处理
                //返回true，说明你自己想根据url，做新的跳转，比如在判断url符合条件的情况下，我想让webView加载http://ask.csdn.net/questions/178242
                return false;
            }

            @Override
            public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
                //返回false，意味着请求过程里，不管有多少次的跳转请求（即新的请求地址），均交给webView自己处理，这也是此方法的默认处理
                //返回true，说明你自己想根据url，做新的跳转，比如在判断url符合条件的情况下，我想让webView加载https://maydaychen.github.io/
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                    if (request.getUrl().toString().contains("github.io")) {
                        view.loadUrl("https://maydaychen.github.io/");
                        return true;
                    }
                }

                return false;
            }

        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == FILECHOOSER_RESULTCODE) {
            if (null == mUploadMessage && null == mUploadCallbackAboveL) return;
            Uri result = data == null || resultCode != RESULT_OK ? null : data.getData();
            if (mUploadCallbackAboveL != null) {
                onActivityResultAboveL(requestCode, resultCode, data);
            } else if (mUploadMessage != null) {
                if (result != null) {
                    String path = getPath(getApplicationContext(), result);
                    Uri uri = Uri.fromFile(new File(path));
                    mUploadMessage.onReceiveValue(uri);
                } else {
                    mUploadMessage.onReceiveValue(imageUri);
                }
                mUploadMessage = null;
            }
        }
    }


    @SuppressWarnings("null")
    @TargetApi(Build.VERSION_CODES.BASE)
    private void onActivityResultAboveL(int requestCode, int resultCode, Intent data) {
        if (requestCode != FILECHOOSER_RESULTCODE
                || mUploadCallbackAboveL == null) {
            return;
        }
        Uri[] results = null;
        if (resultCode == Activity.RESULT_OK) {
            if (data == null) {
                results = new Uri[]{imageUri};
            } else {
                String dataString = data.getDataString();
                ClipData clipData = data.getClipData();
                if (clipData != null) {
                    results = new Uri[clipData.getItemCount()];
                    for (int i = 0; i < clipData.getItemCount(); i++) {
                        ClipData.Item item = clipData.getItemAt(i);
                        results[i] = item.getUri();
                    }
                }
                if (dataString != null)
                    results = new Uri[]{Uri.parse(dataString)};
            }
        }
        if (results != null) {
            mUploadCallbackAboveL.onReceiveValue(results);
            mUploadCallbackAboveL = null;
        } else {
            results = new Uri[]{imageUri};
            mUploadCallbackAboveL.onReceiveValue(results);
            mUploadCallbackAboveL = null;
        }
        return;
    }


    private void take() {
        File imageStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "MyApp");
        // Create the storage directory if it does not exist
        if (!imageStorageDir.exists()) {
            imageStorageDir.mkdirs();
        }
        File file = new File(imageStorageDir + File.separator + "IMG_" + String.valueOf(System.currentTimeMillis()) + ".jpg");
        imageUri = Uri.fromFile(file);
        final List<Intent> cameraIntents = new ArrayList<Intent>();
        final Intent captureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        final PackageManager packageManager = getPackageManager();
        final List<ResolveInfo> listCam = packageManager.queryIntentActivities(captureIntent, 0);
        for (ResolveInfo res : listCam) {
            final String packageName = res.activityInfo.packageName;
            final Intent i = new Intent(captureIntent);
            i.setComponent(new ComponentName(res.activityInfo.packageName, res.activityInfo.name));
            i.setPackage(packageName);
            i.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
            cameraIntents.add(i);

        }
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
        i.setType("image/*");
        Intent chooserIntent = Intent.createChooser(i, "Image Chooser");
        chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, cameraIntents.toArray(new Parcelable[]{}));
        BBSActivity.this.startActivityForResult(chooserIntent, FILECHOOSER_RESULTCODE);
    }

    @SuppressLint("NewApi")
    @TargetApi(Build.VERSION_CODES.KITKAT)
    public static String getPath(final Context context, final Uri uri) {
        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
        // DocumentProvider
        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
            // ExternalStorageProvider
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];
                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }
            }
            // DownloadsProvider
            else if (isDownloadsDocument(uri)) {

                final String id = DocumentsContract.getDocumentId(uri);
                final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
                return getDataColumn(context, contentUri, null, null);
            }
            // MediaProvider
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];
                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }
                final String selection = "_id=?";
                final String[] selectionArgs = new String[]{split[1]};
                return getDataColumn(context, contentUri, selection, selectionArgs);
            }
        }
        // MediaStore (and general)
        else if ("content".equalsIgnoreCase(uri.getScheme())) {
            return getDataColumn(context, uri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }
        return null;
    }


    /**
     * Get the value of the data column for this Uri. This is useful for
     * MediaStore Uris, and other file-based ContentProviders.
     *
     * @param context       The context.
     * @param uri           The Uri to query.
     * @param selection     (Optional) Filter used in the query.
     * @param selectionArgs (Optional) Selection arguments used in the query.
     * @return The value of the _data column, which is typically a file path.
     */
    public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
        Cursor cursor = null;
        final String column = "_data";
        final String[] projection = {column};

        try {
            cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
            if (cursor != null && cursor.moveToFirst()) {
                final int column_index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(column_index);
            }
        } finally {
            if (cursor != null) cursor.close();
        }
        return null;
    }


    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is ExternalStorageProvider.
     */
    public static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getAuthority());
    }


    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is DownloadsProvider.
     */
    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }


    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is MediaProvider.
     */
    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }
}

webview点击链接跳转系统浏览器解决

webView.setWebViewClient(new WebViewClient());

webview有些图片不显示问题

一般是由于Android端使用了https头，而H5端使用了http头，需要两端保持一致
在5.0以上的系统中使用混合模式也能解决此问题

if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.LOLLIPOP）{
getSettings().setMixedContentMode(WebSettings.MIXED_CONTENT_ALWAYS_ALLOW);
}

网页调用拨打电话

@Override
 public boolean shouldOverrideUrlLoading(WebView view, String url) {
     if (url.startsWith("tel:")) {
         Intent intent = new Intent(Intent.ACTION_DIAL, Uri.parse(url));
         startActivity(intent);
         return true;
     }
     return super.shouldOverrideUrlLoading(view, url);
 }