小米手机从相册获照片返回空指针异常
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;
// 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 the remote address
if (isGooglePhotosUri(uri))
return uri.getLastPathSegment();
return getDataColumn(context, uri, null, null);
}
// File
else 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：
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);
}