我是Android Studio的新手，我一直在努力创建一个使用此链接提供的（：scanLibrary）进行扫描的应用，并按照此处https://github.com/jhansireddy/AndroidScannerDemo给出的说明进行操作。没有编译错误，只有一些运行时错误。有人可以帮我弄清楚为什么会这样吗？
这是我的代码
package com.mukesh.android.digiwrite;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import com.scanlibrary.ScanActivity;
import com.scanlibrary.ScanConstants;
import java.io.IOException;
public class MainActivity extends Activity {
private static final String TAG = "tag" ;
private Button click;
private Button gallery;
public final int request_Code = 99;
public ImageView image;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.d(TAG, "part2");
click = (Button)findViewById(R.id.button);
gallery = (Button)findViewById(R.id.button2);
image = (ImageView)findViewById(R.id.imageView);
gallery.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, ScanActivity.class);
intent.putExtra(ScanConstants.OPEN_INTENT_PREFERENCE, ScanConstants.OPEN_MEDIA);
startActivityForResult(intent, request_Code);
Log.d(TAG, "part4");
}
});
/* click.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, ScanActivity.class);
intent.putExtra(ScanConstants.OPEN_INTENT_PREFERENCE, ScanConstants.OPEN_CAMERA);
startActivityForResult(intent, request_Code);
}
});*/
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
Log.d(TAG, "part5");
if (requestCode == request_Code && resultCode == RESULT_OK) {
Uri uri = data.getExtras().getParcelable(ScanConstants.SCANNED_RESULT);
Bitmap bitmap = null;
Log.d(TAG, "part6");
try {
bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), uri);
getContentResolver().delete(uri, null, null);
image.setImageBitmap(bitmap);
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
我还在清单文件中给出了所需的读写权限，如下所示：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.mukesh.android.digiwrite">
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-feature android:name="android.hardware.camera2.full" android:required="false" />
<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>
</application>
</manifest>
但是，只要点击图库按钮并选择图像，应用就会一直关闭。我尝试在android sdk23上运行它。
编辑1
这是我得到的错误。
06-09 18:23:18.899 25835-25835/com.mukesh.android.digiwrite E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.mukesh.android.digiwrite, PID: 25835
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mukesh.android.digiwrite/com.scanlibrary.ScanActivity}: java.lang.SecurityException: Permission Denial: starting Intent { act=android.media.action.IMAGE_CAPTURE flg=0x3 cmp=com.motorola.camera/.Camera clip={text/uri-list U:file:///storage/emulated/0/scanSample/IMG_20170609_182318.jpg} (has extras) } from ProcessRecord{1e3886 25835:com.mukesh.android.digiwrite/u0a131} (pid=25835, uid=10131) with revoked permission android.permission.CAMERA
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2426)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
Caused by: java.lang.SecurityException: Permission Denial: starting Intent { act=android.media.action.IMAGE_CAPTURE flg=0x3 cmp=com.motorola.camera/.Camera clip={text/uri-list U:file:///storage/emulated/0/scanSample/IMG_20170609_182318.jpg} (has extras) } from ProcessRecord{1e3886 25835:com.mukesh.android.digiwrite/u0a131} (pid=25835, uid=10131) with revoked permission android.permission.CAMERA
at android.os.Parcel.readException(Parcel.java:1620)
at android.os.Parcel.readException(Parcel.java:1573)
at android.app.ActivityManagerProxy.startActivity(ActivityManagerNative.java:2679)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1693)
at android.app.Activity.startActivityForResult(Activity.java:4570)
at android.app.Activity.startActivityFromFragment(Activity.java:4556)
at android.app.Activity$HostCallbacks.onStartActivityFromFragment(Activity.java:6652)
at android.app.Fragment.startActivityForResult(Fragment.java:1112)
at android.app.Fragment.startActivityForResult(Fragment.java:1101)
at com.scanlibrary.PickImageFragment.openCamera(PickImageFragment.java:129)
at com.scanlibrary.PickImageFragment.handleIntentPreference(PickImageFragment.java:77)
at com.scanlibrary.PickImageFragment.init(PickImageFragment.java:58)
at com.scanlibrary.PickImageFragment.onCreateView(PickImageFragment.java:48)
at android.app.Fragment.performCreateView(Fragment.java:2220)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:973)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1148)
at android.app.BackStackRecord.run(BackStackRecord.java:793)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1537)
at android.app.FragmentController.execPendingActions(FragmentController.java:325)
at android.app.Activity.performStart(Activity.java:6275)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2389)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2490)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1354)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5443)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
06-09 18:23:20.589 26141-26153/? E/libEGL: validate_display:255 error 3008 (EGL_BAD_DISPLAY)
06-09 18:23:22.793 26217-26217/? E/NEW_BHD: Battery Power Supply logging Daemon start!!!!!
06-09 18:23:22.794 26217-26217/? E/NEW_BHD: Cannot run on production devices!
我的Xml文件
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.mukesh.android.digiwrite.MainActivity">
<ImageView
android:id="@+id/imageView"
android:layout_width="300dp"
android:layout_height="300dp"
app:srcCompat="@drawable/circle"
android:layout_marginTop="50dp"
android:layout_below="@+id/linearlayout"
android:layout_centerHorizontal="true" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_gravity="bottom"
android:gravity="center_horizontal"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true"
android:id="@+id/linearlayout">
<Button
android:id="@+id/button"
android:layout_width="88dp"
android:layout_height="wrap_content"
android:text="@string/button"
android:layout_margin="32dp"
/>
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="32dp"
android:text="@string/button2" />
</LinearLayout>
</RelativeLayout>
我尝试在android sdk 19上运行它，它运行正常。但是在android sdk 23,24,25中它没有用。
谢谢
答案 0 :(得分：0)
你应该遵循this，因为android 6引入了运行时权限。
在android清单中定义所需的权限是不够的，你必须明确地向用户询问。
如果他没有授权（或者你根本不问）你的应用会崩溃。
来自官方文档：
例如，此代码段显示了如何检查活动是否有权写入日历：
// Assume thisActivity is the current activity
int permissionCheck = ContextCompat.checkSelfPermission(thisActivity,
Manifest.permission.WRITE_CALENDAR);
Request the permissions you need
以下代码检查应用是否有权读取用户的联系人，并在必要时请求权限：
// Here, thisActivity is the current activity
if (ContextCompat.checkSelfPermission(thisActivity,
Manifest.permission.READ_CONTACTS)
!= PackageManager.PERMISSION_GRANTED) {
// Should we show an explanation?
if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
Manifest.permission.READ_CONTACTS)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
} else {
// No explanation needed, we can request the permission.
ActivityCompat.requestPermissions(thisActivity,
new String[]{Manifest.permission.READ_CONTACTS},
MY_PERMISSIONS_REQUEST_READ_CONTACTS);
// MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
// app-defined int constant. The callback method gets the
// result of the request.
}
}