前言
提示：我们常见的应该就是APP换头像了，可以拍照以及相册选取，虽然这个功能很常见，但很多比较麻烦，今天分享一个简单的实现方法
一、全局变量定义
private String headStr;//最终上传路径
private Uri imageUri;//图片路径
private int REQUEST_CODE = 88;//相机
private int REQUEST_CODEXC = 99;//相册
二、得到图片后转String路径工具类
package com.wzj.footprint.utils;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import android.util.Log;
import java.io.File;
public class UriToPathUtil {
/**
*Uri 转 path
*/
public static String getPathFromUri(Context context, Uri uri) {
String path = null;
if (DocumentsContract.isDocumentUri(context, uri)) {
//如果是document类型的Uri，通过document id处理，内部会调用Uri.decode(docId)进行解码
String docId = DocumentsContract.getDocumentId(uri);
//primary:Azbtrace.txt
//video:A1283522
String[] splits = docId.split(":");
String type = null, id = null;
if(splits.length == 2) {
type = splits[0];
id = splits[1];
}
switch (uri.getAuthority()) {
case "com.android.externalstorage.documents":
if("primary".equals(type)) {
path = Environment.getExternalStorageDirectory() + File.separator + id;
}
break;
case "com.android.providers.downloads.documents":
if("raw".equals(type)) {
path = id;
} else {
Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(docId));
path = getMediaPathFromUri(context, contentUri, null, null);
}
break;
case "com.android.providers.media.documents":
Uri externalUri = null;
switch (type) {
case "image":
externalUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
break;
case "video":
externalUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
break;
case "audio":
externalUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
break;
}
if(externalUri != null) {
String selection = "_id=?";
String[] selectionArgs = new String[]{
id };
path = getMediaPathFromUri(context, externalUri, selection, selectionArgs);
}
break;
}
} else if (ContentResolver.SCHEME_CONTENT.equalsIgnoreCase(uri.getScheme())) {
path = getMediaPathFromUri(context, uri, null, null);
} else if (ContentResolver.SCHEME_FILE.equalsIgnoreCase(uri.getScheme())) {
//如果是file类型的Uri(uri.fromFile)，直接获取图片路径即可
path = uri.getPath();
}else {
path = uri.getPath();
}
//确保如果返回路径，则路径合法
return path == null ? null : (new File(path).exists() ? path : null);
}
private static String getMediaPathFromUri(Context context, Uri uri, String selection, String[] selectionArgs) {
String path;
String authroity = uri.getAuthority();
path = uri.getPath();
String sdPath = Environment.getExternalStorageDirectory().getAbsolutePath();
if(!path.startsWith(sdPath)) {
int sepIndex = path.indexOf(File.separator, 1);
if(sepIndex == -1) path = null;
else {
path = sdPath + path.substring(sepIndex);
}
}
if(path == null || !new File(path).exists()) {
ContentResolver resolver = context.getContentResolver();
String[] projection = new String[]{
MediaStore.MediaColumns.DATA };
Cursor cursor = resolver.query(uri, projection, selection, selectionArgs, null);
if (cursor != null) {
if (cursor.moveToFirst()) {
try {
int index = cursor.getColumnIndexOrThrow(projection[0]);
if (index != -1) path = cursor.getString(index);
Log.i("Uri 转 path ", "getMediaPathFromUri query " + path);
} catch (IllegalArgumentException e) {
e.printStackTrace();
path = null;
} finally {
cursor.close();
}
}
}
}
return path;
}
}
三、onActivityResult返回值
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode != RESULT_OK) {
return;
}
if (requestCode == REQUEST_CODEXC) {
//相册
imageUri = data.getData(); //获取系统返回的照片的Uri
// Bitmap bitmap = null;
// try {
// bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));
// imag_logo.setImageBitmap(bitmap);
// } catch (FileNotFoundException e) {
// e.printStackTrace();
// }
headStr = UriToPathUtil.getPathFromUri(PersonalInformation.this, imageUri);//将Uri转path;
System.out.println("上传路径返回值打印--相册：" + headStr);
OSSImag(headStr);//oss上传
} else {
//相机
headStr = UriToPathUtil.getPathFromUri(PersonalInformation.this, imageUri);//将Uri转path;
System.out.println("上传路径返回值打印--拍照：" + headStr);
OSSImag(headStr);
}
}
四、拍照及相册选取
1.拍照
代码如下（示例）：
// 创建File对象，用于存储拍照后的图片
//存放在手机SD卡的应用关联缓存目录下
File outputImage = new File(getExternalCacheDir(), "output_image.jpg");
/* 从Android 6.0系统开始，读写SD卡被列为了危险权限，如果将图片存放在SD卡的任何其他目录，
都要进行运行时权限处理才行，而使用应用关联 目录则可以跳过这一步
*/
try {
if (outputImage.exists()) {
outputImage.delete();
}
} catch (Exception e) {
e.printStackTrace();
}
/*
7.0系统开始，直接使用本地真实路径的Uri被认为是不安全的，会抛 出一个FileUriExposedException异常。
而FileProvider则是一种特殊的内容提供器，它使用了和内 容提供器类似的机制来对数据进行保护，
可以选择性地将封装过的Uri共享给外部，从而提高了 应用的安全性
*/
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
//大于等于版本24（7.0）的场合
imageUri = FileProvider.getUriForFile(PersonalInformation.this, "com.wzj.footprint.fileprovider", outputImage);
} else {
//小于android 版本7.0（24）的场合
imageUri = Uri.fromFile(outputImage);
}
//启动相机程序
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
//MediaStore.ACTION_IMAGE_CAPTURE = android.media.action.IMAGE_CAPTURE
intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
startActivityForResult(intent, REQUEST_CODE);
2.相册
代码如下（示例）：
//在这里跳转到手机系统相册里面
//在这里跳转到手机系统相册里面
Intent intent = new Intent(Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, REQUEST_CODEXC);
五、权限
<!-- 拍照选取相册图片需要权限 -->
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
总结
有没有感觉很简单，大致流程就是这样，1：权限 2：跳转拍照或者相册 3：拿返回值进行显示。an