我正在尝试使用以下代码从手机的相机拍摄照片：
activity_main.xml中：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Button
android:id="@+id/btnCapture"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Camera" />
</LinearLayout>
MainActivity.java：
public class CameraDemoActivity extends Activity {
int TAKE_PHOTO_CODE = 0;
public static int count = 0;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Here, we are making a folder named picFolder to store
// pics taken by the camera using this application.
final String dir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + "/picFolder/";
File newdir = new File(dir);
newdir.mkdirs();
Button capture = (Button) findViewById(R.id.btnCapture);
capture.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Here, the counter will be incremented each time, and the
// picture taken by camera will be stored as 1.jpg,2.jpg
// and likewise.
count++;
String file = dir+count+".jpg";
File newfile = new File(file);
try {
newfile.createNewFile();
}
catch (IOException e)
{
}
Uri outputFileUri = Uri.fromFile(newfile);
Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
startActivityForResult(cameraIntent, TAKE_PHOTO_CODE);
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == TAKE_PHOTO_CODE && resultCode == RESULT_OK) {
Log.d("CameraDemo", "Pic saved");
}
}
}
我还将这些权限添加到Manifest.xml：
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
但我收到此错误消息：
android.os.FileUriExposedException： file：///storage/emulated/0/Pictures/picFolder/1.jpg暴露在app之外 通过ClipData.Item.getUri（）
问题是什么，我该如何解决？
编辑：这是更新后的代码：
MainActivity：
package com.m.textdetection;
import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.icu.text.SimpleDateFormat;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v4.content.FileProvider;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import java.io.File;
import java.io.IOException;
import java.util.Date;
public class MainActivity extends AppCompatActivity {
private MyTessOCR mTessOCR = new MyTessOCR(MainActivity.this);
private Button takePictureButton;
private ImageView imageView;
/*
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
takePictureButton = (Button) findViewById(R.id.button_image);
imageView = (ImageView) findViewById(R.id.imageview);
if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
takePictureButton.setEnabled(false);
ActivityCompat.requestPermissions(this, new String[] { Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE }, 0);
}
}
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
if (requestCode == 0) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED
&& grantResults[1] == PackageManager.PERMISSION_GRANTED) {
takePictureButton.setEnabled(true);
}
}
}
public void takePicture(View view) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
file = Uri.fromFile(getOutputMediaFile());
intent.putExtra(MediaStore.EXTRA_OUTPUT, file);
startActivityForResult(intent, 100);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
if (requestCode == 100) {
if (resultCode == RESULT_OK) {
imageView.setImageURI(File);
}
}
}
private static File getOutputMediaFile(){
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "CameraDemo");
if (!mediaStorageDir.exists()){
if (!mediaStorageDir.mkdirs()){
return null;
}
}
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
return new File(mediaStorageDir.getPath() + File.separator +
"IMG_"+ timeStamp + ".jpg");
}
*/
int TAKE_PHOTO_CODE = 0;
public static int count = 0;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final String dir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + "/picFolder/";
File newdir = new File(dir);
newdir.mkdirs();
Button capture = (Button) findViewById(R.id.btnCapture);
capture.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Here, the counter will be incremented each time, and the
// picture taken by camera will be stored as 1.jpg,2.jpg
// and likewise.
count++;
String file = dir+count+".jpg";
File newfile = new File(file);
try {
newfile.createNewFile();
}
catch (IOException e)
{
}
// Uri outputFileUri = Uri.fromFile(newfile);
Uri outputFileUri = FileProvider.getUriForFile(MainActivity.this, BuildConfig.APPLICATION_ID, newfile);
Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
startActivityForResult(cameraIntent, TAKE_PHOTO_CODE);
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == TAKE_PHOTO_CODE && resultCode == RESULT_OK) {
Log.d("CameraDemo", "Pic saved");
}
}
private void doOCR()
{
// String temp = mTessOCR.getOCRResult(bitmap);
}
}
清单：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.m.textdetection">
<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"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="${applicationId}.my.package.name.provider"
android:exported="false"
android:grantUriPermissions="true"
tools:replace="android:authorities">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/provider_paths"
tools:replace="android:resource"/>
</provider>
</application>
</manifest>
的build.gradle（APP）：
apply plugin: 'com.android.application'
android {
compileSdkVersion 27
buildToolsVersion "27.0.3"
defaultConfig {
applicationId "com.m.textdetection"
minSdkVersion 21
targetSdkVersion 27
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:27.0.2'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
testCompile 'junit:junit:4.12'
compile 'com.rmtheis:tess-two:6.0.3'
compile 'com.android.support:support-v4:27.0.2'
}
这是新的错误：
java.lang.NullPointerException：尝试调用虚方法 “android.content.res.XmlResourceParser android.content.pm.ProviderInfo.loadXmlMetaData（android.content.pm.PackageManager， “空对象引用
上的java.lang.String）”
发生在这一行：
Uri outputFileUri = FileProvider.getUriForFile(MainActivity.this, BuildConfig.APPLICATION_ID, newfile);
Edir2：
package com.m.textdetection;
import android.content.Context;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.os.Environment;
import android.util.Log;
import com.googlecode.tesseract.android.TessBaseAPI;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
public class MyTessOCR {
private String datapath;
private TessBaseAPI mTess;
Context context;
public MyTessOCR(Context context)
{
this.context = context;
datapath = Environment.getExternalStorageDirectory() + "/ocrctz/";
File dir = new File(datapath + "/tessdata/");
File file = new File(datapath + "/tessdata/" + "eng.traineddata");
if (!file.exists())
{
Log.d("mylog", "in file doesn't exist");
dir.mkdirs();
copyFile(context);
}
mTess = new TessBaseAPI();
String language = "eng";
mTess.init(datapath, language);
//Auto only
mTess.setPageSegMode(TessBaseAPI.PageSegMode.PSM_AUTO_ONLY);
}
public void stopRecognition() {
mTess.stop();
}
public String getOCRResult(Bitmap bitmap)
{
mTess.setImage(bitmap);
String result = mTess.getUTF8Text();
return result;
}
public void onDestroy()
{
if (mTess != null)
mTess.end();
}
private void copyFile(Context context)
{
AssetManager assetManager = context.getAssets();
try
{ InputStream in = assetManager.open("eng.traineddata");
OutputStream out = new FileOutputStream(datapath + "/tessdata/" + "eng.traineddata");
byte[] buffer = new byte[1024];
int read = in.read(buffer);
while (read != -1) {
out.write(buffer, 0, read);
read = in.read(buffer); }
} catch (Exception e)
{
Log.d("mylog", "couldn't copy with the following error : "+e.toString());
}
}
}
答案 0 :(得分：0)
试试看！只需将以下代码粘贴到活动onCreate（）
中StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
StrictMode.setVmPolicy(builder.build());
它将忽略URI暴露