Android：在不同的Android版本中上传图片时出错
费德宇
问题内容：
问题答案：
我在不同的android版本中上传图片时遇到问题。我需要为php服务器发送图像，所以我正在使用网络服务。我用Froyo e Jelly
Beans的版本进行了测试，它们可以工作，但KitKat不能工作。我在阅读有关MediaStore的文章时，我看到了不同的方式，但不管是对还是错。
我调试了项目，然后发现，在KitKat中，路径为NULL，Logcat在KitKat中告诉我“ Java Null
Pointer”。我该如何做一个适用于所有版本的应用程序。
UploadImage.java
package br.gov.rj.barraemexposicao;
import android.app.ProgressDialog;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.provider.MediaStore;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class EnviaFoto extends ActionBarActivity {
final int PICK_FILE_RESULT_CODE = 1;
final int CAMERA_IMAGE =2;
TextView messageText;
Button uploadButton;
Button btnTiraFoto;
Button selectImage;
ImageView imgFoto;
int serverResponseCode = 0;
ProgressDialog dialog = null;
String upLoadServerUri = "http://www.kweekdesign.com.br/test/recebe/UploadToServer.php";
String filePath = "";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_envia_foto);
selectImage = (Button) findViewById(R.id.selectImage);
imgFoto = (ImageView) findViewById(R.id.imgFoto);
messageText = (TextView)findViewById(R.id.messageText);
uploadButton = (Button)findViewById(R.id.uploadButton);
btnTiraFoto = (Button) findViewById(R.id.btnTiraFoto);
upLoadServerUri = "http://www.kweekdesign.com.br/test/recebe/UploadToServer.php";
addListeners();
}
public String uriToPath(Uri uri) {
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = managedQuery(uri, projection, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
@Override
protected void onActivityResult (int requestCode, int resultCode, Intent data){
if (data != null && (requestCode == PICK_FILE_RESULT_CODE || requestCode == CAMERA_IMAGE)){
filePath = uriToPath(data.getData());
imgFoto.setImageURI(data.getData());
uploadButton.setVisibility(1);
}
}
public int uploadFile(String sourceFileUri) {
String fileName = sourceFileUri;
HttpURLConnection conn = null;
DataOutputStream dos = null;
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
int bytesRead, bytesAvailable, bufferSize;
byte[] buffer;
int maxBufferSize = 1 * 1024 * 1024;
File sourceFile = new File(sourceFileUri);
if (!sourceFile.isFile()) {
dialog.dismiss();
Log.e("uploadFile", "Source File not exist :" + filePath);
runOnUiThread(new Runnable() {
public void run() {
messageText.setText("Source File not exist :"+filePath);
}
});
return 0;
}
else
{
try {
// open a URL connection to the Servlet
FileInputStream fileInputStream = new FileInputStream(sourceFile);
URL url = new URL(upLoadServerUri);
// Open a HTTP connection to the URL
conn = (HttpURLConnection) url.openConnection();
conn.setDoInput(true); // Allow Inputs
conn.setDoOutput(true); // Allow Outputs
conn.setUseCaches(false); // Don't use a Cached Copy
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("ENCTYPE", "multipart/form-data");
conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
conn.setRequestProperty("uploaded_file", fileName);
dos = new DataOutputStream(conn.getOutputStream());
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=\"uploaded_file\";filename=\""
+ fileName + "\"" + lineEnd);
dos.writeBytes(lineEnd);
// create a buffer of maximum size
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
buffer = new byte[bufferSize];
// read file and write it into form...
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
while (bytesRead > 0) {
dos.write(buffer, 0, bufferSize);
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
}
// send multipart form data necesssary after file data...
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
// Responses from the server (code and message)
serverResponseCode = conn.getResponseCode();
String serverResponseMessage = conn.getResponseMessage();
Log.i("uploadFile", "HTTP Response is : "
+ serverResponseMessage + ": " + serverResponseCode);
if(serverResponseCode == 200){
runOnUiThread(new Runnable() {
public void run() {
String msg = "Envio feito com sucesso!";
messageText.setText(msg);
Toast.makeText(EnviaFoto.this, "File Upload Complete.",
Toast.LENGTH_SHORT).show();
}
});
}
//close the streams //
fileInputStream.close();
dos.flush();
dos.close();
} catch (MalformedURLException ex) {
dialog.dismiss();
ex.printStackTrace();
runOnUiThread(new Runnable() {
public void run() {
messageText.setText("MalformedURLException Exception : check script url.");
Toast.makeText(EnviaFoto.this, "MalformedURLException",
Toast.LENGTH_SHORT).show();
}
});
Log.e("Upload file to server", "error: " + ex.getMessage(), ex);
} catch (Exception e) {
dialog.dismiss();
e.printStackTrace();
runOnUiThread(new Runnable() {
public void run() {
messageText.setText("Got Exception : see logcat ");
Toast.makeText(EnviaFoto.this, "Got Exception : see logcat ",
Toast.LENGTH_SHORT).show();
}
});
Log.e("Upload file to server Exception", "Exception : "
+ e.getMessage(), e);
}
dialog.dismiss();
return serverResponseCode;
} // End else block
}
private void addListeners(){
selectImage.setOnClickListener(new View.OnClickListener(){
public void onClick(View view){
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
Intent chooser = Intent.createChooser(intent,"Escolha a foto");
intent.setType("image/*");
try {
startActivityForResult(chooser, PICK_FILE_RESULT_CODE );
}catch (ActivityNotFoundException e){
Log.e("tag", e.getMessage());
}
}
});
uploadButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
dialog = ProgressDialog.show(EnviaFoto.this, "", "Enviando foto...", true);
new Thread(new Runnable() {
public String uriToPath(Uri uri) {
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = managedQuery(uri, projection, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
protected void onActivityResult (int requestCode, int resultCode, Intent data){
if (data != null && requestCode == PICK_FILE_RESULT_CODE){
filePath = uriToPath(data.getData());
imgFoto.setImageURI(data.getData());
uploadButton.setVisibility(1);
}
} public void run() {
runOnUiThread(new Runnable() {
public void run() {
messageText.setText("Enviando foto...");
}
});
uploadFile(filePath);
}
}).start();
}
});
btnTiraFoto.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
startActivityForResult(new Intent(MediaStore.ACTION_IMAGE_CAPTURE), CAMERA_IMAGE);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.envia_foto, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
表现
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="br.gov.rj.barraemexposicao" >
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="br.gov.rj.barraemexposicao.EnviaFoto"
android:label="@string/app_name"
android:screenOrientation="portrait" >
<intent-filter>
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="br.gov.rj.barraemexposicao.Enquete"
android:label="@string/title_activity_enquete" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
LogCat
07-04 08:46:54.084 13565-13565/br.gov.rj.barraemexposicao I/Adreno-EGL﹕ <qeglDrvAPI_eglInitialize:410>: EGL 1.4 QUALCOMM build: AU_LINUX_ANDROID_LNX.LA.3.5.1_RB1.04.04.02.048.018_msm8226_LNX.LA.3.5.1_RB1__release_AU ()
OpenGL ES Shader Compiler Version: E031.24.00.08
Build Date: 03/07/14 Fri
Local Branch:
Remote Branch: quic/LNX.LA.3.5.1_RB1.1
Local Patches: NONE
Reconstruct Branch: AU_LINUX_ANDROID_LNX.LA.3.5.1_RB1.04.04.02.048.018 + f2fd134 + NOTHING
07-04 08:46:54.157 13565-13565/br.gov.rj.barraemexposicao D/OpenGLRenderer﹕ Enabling debug mode 0
07-04 08:47:03.105 13565-13565/br.gov.rj.barraemexposicao D/AndroidRuntime﹕ Shutting down VM
07-04 08:47:03.121 13565-13565/br.gov.rj.barraemexposicao E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: br.gov.rj.barraemexposicao, PID: 13565
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=2, result=-1, data=Intent { act=inline-data (has extras) }} to activity {br.gov.rj.barraemexposicao/br.gov.rj.barraemexposicao.EnviaFoto}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()' on a null object reference
at android.app.ActivityThread.deliverResults(ActivityThread.java:3432)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3475)
at android.app.ActivityThread.access$1300(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1258)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()' on a null object reference
at android.content.ContentResolver.acquireUnstableProvider(ContentResolver.java:1420)
at android.content.ContentResolver.query(ContentResolver.java:445)
at android.content.ContentResolver.query(ContentResolver.java:404)
at br.gov.rj.barraemexposicao.EnviaFoto.uriToPath(EnviaFoto.java:80)
at br.gov.rj.barraemexposicao.EnviaFoto.onActivityResult(EnviaFoto.java:97)
at android.app.Activity.dispatchActivityResult(Activity.java:5446)
at android.app.ActivityThread.deliverResults(ActivityThread.java:3428)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3475)
at android.app.ActivityThread.access$1300(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1258)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
07-04 08:47:05.066 13565-13565/br.gov.rj.barraemexposicao I/Process﹕ Sending signal. PID: 13565 SIG: 9
07-04 08:51:33.298 15518-15518/br.gov.rj.barraemexposicao I/Adreno-EGL﹕ <qeglDrvAPI_eglInitialize:410>: EGL 1.4 QUALCOMM build: AU_LINUX_ANDROID_LNX.LA.3.5.1_RB1.04.04.02.048.018_msm8226_LNX.LA.3.5.1_RB1__release_AU ()
OpenGL ES Shader Compiler Version: E031.24.00.08
Build Date: 03/07/14 Fri
Local Branch:
Remote Branch: quic/LNX.LA.3.5.1_RB1.1
Local Patches: NONE
Reconstruct Branch: AU_LINUX_ANDROID_LNX.LA.3.5.1_RB1.04.04.02.048.018 + f2fd134 + NOTHING
07-04 08:51:33.393 15518-15518/br.gov.rj.barraemexposicao D/OpenGLRenderer﹕ Enabling debug mode 0
07-04 08:52:08.015 15518-15530/br.gov.rj.barraemexposicao W/CursorWrapperInner﹕ Cursor finalized without prior close()
07-04 08:52:10.068 15518-16522/br.gov.rj.barraemexposicao E/AndroidRuntime﹕ FATAL EXCEPTION: Thread-34287
Process: br.gov.rj.barraemexposicao, PID: 15518
java.lang.NullPointerException: Attempt to invoke virtual method 'char[] java.lang.String.toCharArray()' on a null object reference
at java.io.File.fixSlashes(File.java:185)
at java.io.File.<init>(File.java:134)
at br.gov.rj.barraemexposicao.EnviaFoto.uploadFile(EnviaFoto.java:102)
at br.gov.rj.barraemexposicao.EnviaFoto$6$1.run(EnviaFoto.java:277)
at java.lang.Thread.run(Thread.java:811)
07-04 08:52:10.815 15518-15518/br.gov.rj.barraemexposicao E/WindowManager﹕ android.view.WindowLeaked: Activity br.gov.rj.barraemexposicao.EnviaFoto has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{65280820 V.E..... R......D 0,0-684,192} that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:359)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:248)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
at android.app.Dialog.show(Dialog.java:286)
at android.app.ProgressDialog.show(ProgressDialog.java:116)
at android.app.ProgressDialog.show(ProgressDialog.java:99)
at br.gov.rj.barraemexposicao.EnviaFoto$6.onClick(EnviaFoto.java:250)
at android.view.View.performClick(View.java:4456)
at android.view.View$PerformClick.run(View.java:18465)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
07-04 09:03:23.546 18083-18083/br.gov.rj.barraemexposicao I/Adreno-EGL﹕ <qeglDrvAPI_eglInitialize:410>: EGL 1.4 QUALCOMM build: AU_LINUX_ANDROID_LNX.LA.3.5.1_RB1.04.04.02.048.018_msm8226_LNX.LA.3.5.1_RB1__release_AU ()
OpenGL ES Shader Compiler Version: E031.24.00.08
Build Date: 03/07/14 Fri
Local Branch:
Remote Branch: quic/LNX.LA.3.5.1_RB1.1
Local Patches: NONE
Reconstruct Branch: AU_LINUX_ANDROID_LNX.LA.3.5.1_RB1.04.04.02.048.018 + f2fd134 + NOTHING
07-04 09:03:23.614 18083-18083/br.gov.rj.barraemexposicao D/OpenGLRenderer﹕ Enabling debug mode 0
07-04 09:04:14.226 18083-18096/br.gov.rj.barraemexposicao W/CursorWrapperInner﹕ Cursor finalized without prior close()
07-04 09:04:14.428 18083-18083/br.gov.rj.barraemexposicao I/Adreno-EGL﹕ <qeglDrvAPI_eglInitialize:410>: EGL 1.4 QUALCOMM build: AU_LINUX_ANDROID_LNX.LA.3.5.1_RB1.04.04.02.048.018_msm8226_LNX.LA.3.5.1_RB1__release_AU ()
OpenGL ES Shader Compiler Version: E031.24.00.08
Build Date: 03/07/14 Fri
Local Branch:
Remote Branch: quic/LNX.LA.3.5.1_RB1.1
Local Patches: NONE
Reconstruct Branch: AU_LINUX_ANDROID_LNX.LA.3.5.1_RB1.04.04.02.048.018 + f2fd134 + NOTHING
07-04 09:04:17.318 18083-19131/br.gov.rj.barraemexposicao E/AndroidRuntime﹕ FATAL EXCEPTION: Thread-34498
Process: br.gov.rj.barraemexposicao, PID: 18083
java.lang.NullPointerException: Attempt to invoke virtual method 'char[] java.lang.String.toCharArray()' on a null object reference
at java.io.File.fixSlashes(File.java:185)
at java.io.File.<init>(File.java:134)
at br.gov.rj.barraemexposicao.EnviaFoto.uploadFile(EnviaFoto.java:100)
at br.gov.rj.barraemexposicao.EnviaFoto$6$1.run(EnviaFoto.java:275)
at java.lang.Thread.run(Thread.java:811)
07-04 09:04:18.179 18083-18083/br.gov.rj.barraemexposicao E/WindowManager﹕ android.view.WindowLeaked: Activity br.gov.rj.barraemexposicao.EnviaFoto has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{65280100 V.E..... R......D 0,0-684,192} that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:359)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:248)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
at android.app.Dialog.show(Dialog.java:286)
at android.app.ProgressDialog.show(ProgressDialog.java:116)
at android.app.ProgressDialog.show(ProgressDialog.java:99)
at br.gov.rj.barraemexposicao.EnviaFoto$6.onClick(EnviaFoto.java:248)
at android.view.View.performClick(View.java:4456)
at android.view.View$PerformClick.run(View.java:18465)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
实例对话框后更新
07-04 09:54:17.341 26763-26763/br.gov.rj.barraemexposicao D/AndroidRuntime﹕ Shutting down VM 07-04 09:54:17.364 26763-26763/br.gov.rj.barraemexposicao E/AndroidRuntime﹕ FATAL EXCEPTION: main Process: br.gov.rj.barraemexposicao, PID: 26763 java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{br.gov.rj.barraemexposicao/br.gov.rj.barraemexposicao.EnviaFoto}: java.lang.InstantiationException: br.gov.rj.barraemexposicao.EnviaFoto at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2124) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2257) at android.app.ActivityThread.access$800(ActivityThread.java:139) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:136) at android.app.ActivityThread.main(ActivityThread.java:5086) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601) Caused by: java.lang.InstantiationException: br.gov.rj.barraemexposicao.EnviaFoto at java.lang.Class.newInstance(Class.java:1561) at android.app.Instrumentation.newActivity(Instrumentation.java:1084) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2115) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2257) at android.app.ActivityThread.access$800(ActivityThread.java:139) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:136) at android.app.ActivityThread.main(ActivityThread.java:5086) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
问题答案：
好，关于这个例外
java.lang.NullPointerException: Attempt to invoke virtual method 'char[] java.lang.String.toCharArray()' on a null object reference
使用“ 照片” 应用程序时可能会遇到此异常，但在“ 图库” 应用程序中却很少见。这可能很重要，因为在Android最新版本5.0
Lollipop中 ，他们删除了 Gallery 应用程序，而现在仅具有 Photos
应用程序（不同的供应商可能有自己的其他内置照片应用程序，当然用户也可以使用任何外部应用程序）
因此，您将获得`filePath = null’。现在的问题是 为什么它为空？ 。
因此，可能有两个原因。
第一种是您的uriToPath(Uri uri)方法无法正常工作，第二种是您Uri从中获取的data.getData()方法不正确。
您的uriToPath(Uri uri)方法似乎是正确的，所以问题出在您的中Uri。您可能已经注意到，如果从获取的图像 库
的应用程序，还有机会少，你得到null的filePath，但如果你正在使用 照片 应用程序中的机会增加。
发生这种情况是因为您的“ 照片”
应用显示的照片可能不在您的本地设备上，而这些照片实际上在Google服务器上。因此，当您Uri通过选择照片进行询问时，它会提供链接到该服务器的
Uri 。
Uri可能是这样
content://com.google.android.apps.photos.content/0/https%3A%2F%2Flh3.googleusercontent.com%2FL-3Jm0TaSqnuKkitli5mK0-d
而不是您的本地设备。本地设备Uri将像这样
content://media/external/images/media/49518
由于这种差异，您uriToPath(Uri uri)将返回null。
因此，请检查第Uri一个并相应地从本地设备或服务器获取图像。
您可以使用DocumentsProvider
API，因此不必担心本地和服务器的文件。
private Bitmap getBitmapFromUri(Uri uri) throws IOException {
ParcelFileDescriptor parcelFileDescriptor =
getContentResolver().openFileDescriptor(uri, "r");
FileDescriptor fileDescriptor = parcelFileDescriptor.getFileDescriptor();
Bitmap image = BitmapFactory.decodeFileDescriptor(fileDescriptor);
parcelFileDescriptor.close();
return image;
}
但是，如果您在“ 照片” 应用程序中有一些本地照片，则选择这些 照片 后，您将获得本地 Uri ，它将为您提供正确的文件路径。
您还可以在“ 照片” 应用本身中下载照片（位于Google服务器上），以后再使用。
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