小米手机从相册获照片返回空指针异常

来源：互联网发布：淘宝可以参加哪些活动编辑：程序博客网时间：2024/04/30 03:11

小米手机选择了图片之后，小米机会崩掉（别的机子，啥版本都没问题）。看异常信息，指示cursor.moveToFirst()，空指针异常。也就是说，cursor为空。是uri的问题，4.4之前，返回的是包含图片绝对路劲的，4.4之后，返回的不再是绝对路劲了，而是一个图片的编码。小米不论版本高低，小米机会崩掉，得到的只是一个图片编码。这时需要去转换为绝对路径，才能方便使用。下面方法是可以得到绝对路径的方法，是大神封装好了，封装成了一个pictureHelper工具类。

吐槽一下，除了小米，用ACTION_PICK，都能得到一个图片的绝对路径。如果是小米，用ACTION_PICK，就需要去转化了。但是，小米用ACTION_GET_CONTENT或者ACTION_OPEN_DOCUMENT，低版本，也能得到绝对路径。。最后统一的处理方法就是，用ACTION_GET_CONTENT，然后分版本处理，低版本还是旧的方法，高版本，用pictureHelper工具类处理得到绝对路径。

package com.xxxe.utils;import android.annotation.SuppressLint;import android.content.ContentUris;import android.content.Context;import android.database.Cursor;import android.net.Uri;import android.os.Build;import android.os.Environment;import android.provider.DocumentsContract;import android.provider.MediaStore;/** *  小米手机获取本地相册图片出现空指针异常处理类 * @author dec * */public class MiPictureHelper {@SuppressLint("NewApi")public static String getPath(final Context context, final Uri uri) {final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;// DocumentProviderif (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {// ExternalStorageProviderif (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];}}// DownloadsProviderelse 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);}// MediaProviderelse 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 the remote addressif (isGooglePhotosUri(uri))return uri.getLastPathSegment();return getDataColumn(context, uri, null, null);}// Fileelse if ("file".equalsIgnoreCase(uri.getScheme())) {return uri.getPath();}return null;}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 index = cursor.getColumnIndexOrThrow(column);return cursor.getString(index);}} finally {if (cursor != null)cursor.close();}return null;}public static boolean isExternalStorageDocument(Uri uri) {return "com.android.externalstorage.documents".equals(uri.getAuthority());}public static boolean isDownloadsDocument(Uri uri) {return "com.android.providers.downloads.documents".equals(uri.getAuthority());}public static boolean isMediaDocument(Uri uri) {return "com.android.providers.media.documents".equals(uri.getAuthority());}private static boolean isGooglePhotosUri(Uri uri) {return "com.google.android.apps.photos.content".equals(uri.getAuthority());}}

如果是想要获取相册中图片的路径，直接这样调用：

protected void onActivityResult(int requestCode, int resultCode, Intent data) {switch (requestCode) {case PICK_PICTURE:// 选取照片if(data!=null){try {Uri uri = data.getData();String pickPath = MiPictureHelper.getPath(mContext, uri);  // 获取图片路径的方法调用System.out.println("图片路径 -->> " + pickPath);}}}}}

====================== 我是一条分割线 ==========================

下面是其他开发者的处理方法

     * 解决小米手机上获取图片路径为null的情况       * @param intent       * @return       */       public Uri getPictureUri(android.content.Intent intent) {                Uri uri = intent.getData();                String type = intent.getType();                if (uri.getScheme().equals("file") && (type.contains("image/"))) {                    String path = uri.getEncodedPath();                    if (path != null) {                        path = Uri.decode(path);                        ContentResolver cr = this.getContentResolver();                        StringBuffer buff = new StringBuffer();                        buff.append("(").append(Images.ImageColumns.DATA).append("=")                                .append("'" + path + "'").append(")");                        Cursor cur = cr.query(Images.Media.EXTERNAL_CONTENT_URI,                                new String[] { Images.ImageColumns._ID },                                buff.toString(), null, null);                        int index = 0;                        for (cur.moveToFirst(); !cur.isAfterLast(); cur.moveToNext()) {                            index = cur.getColumnIndex(Images.ImageColumns._ID);                            // set _id value                            index = cur.getInt(index);                        }                        if (index == 0) {                            // do nothing                        } else {                            Uri uri_temp = Uri                                    .parse("content://media/external/images/media/"                                            + index);                            if (uri_temp != null) {                                uri = uri_temp;                            }                        }                    }                }                return uri;            }

他们这样调用方法：

<span style="white-space:pre"></span>if (data == null) {  return;  }  uri = data.getData();  uri = getPictureUri(data); // 方法调用        String[] proj = { MediaStore.Images.Media.DATA };          Cursor cursor = managedQuery(uri, proj, null, null, null);          if(cursor!=null) {  int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);                  cursor.moveToFirst();                  String path = cursor.getString(column_index);// 图片在的路径                  Intent intent3 = new Intent(this, SYClipActivity.class);                  intent3.putExtra("path", path);                  startActivityForResult(intent3, IMAGE_COMPLETE);  }

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