我一直收到这个错误。我不确定原因，我已经检查了我的权限
04-20 19:35:19.556 12158-12158/com.example.matts.myapplication D/OpenGLRenderer﹕ Enabling debug mode 0
04-20 19:35:19.586 12158-12158/com.example.matts.myapplication I/Timeline﹕ Timeline: Activity_idle id: android.os.BinderProxy@420d5168 time:146616646
04-20 19:35:22.006 12158-12158/com.example.matts.myapplication I/Timeline﹕ Timeline: Activity_launch_request id:com.example.matts.myapplication time:146619061
04-20 19:35:22.086 12158-12158/com.example.matts.myapplication I/Timeline﹕ Timeline: Activity_idle id: android.os.BinderProxy@42206588 time:146619146
04-20 19:35:27.196 12158-12158/com.example.matts.myapplication D/AndroidRuntime﹕ Shutting down VM
04-20 19:35:27.196 12158-12158/com.example.matts.myapplication W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x41598db8)
04-20 19:35:27.196 12158-12158/com.example.matts.myapplication E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.matts.myapplication, PID: 12158
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=null} to activity {com.example.matts.myapplication/com.example.matts.myapplication.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.deliverResults(ActivityThread.java:3389)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3432)
at android.app.ActivityThread.access$1300(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1253)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5146)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:732)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.matts.myapplication.MainActivity.onActivityResult(MainActivity.java:47)
at android.app.Activity.dispatchActivityResult(Activity.java:5423)
at android.app.ActivityThread.deliverResults(ActivityThread.java:3385)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3432)
at android.app.ActivityThread.access$1300(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1253)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5146)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:732)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
at dalvik.system.NativeStart.main(Native Method)
这是代码。我想要做的是拍照，将照片保存在tmp位置，然后将图片加载到位图imageview中。
代码：
package com.example.matts.myapplication;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import java.io.File;
public class MainActivity extends Activity {
static final int REQUEST_IMAGE_CAPTURE = 1;
private ImageView imageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
openCamera();
setContentView(R.layout.activity_main);
isExternalStorageWritable();
}
public void openCamera() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
File file = new File(Environment.getExternalStorageDirectory()+ File.separator + "image.jpg");
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file));
startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
}
protected void onActivityResult(int requestCode, int resultCode, Intent data){
//Check that request code matches ours:
if (requestCode == REQUEST_IMAGE_CAPTURE){
//Get our saved file into a bitmap object:
File file = new File(Environment.getExternalStorageDirectory()+File.separator + "image.jpg");
Bitmap image = decodeSampledBitmapFromFile(file.getAbsolutePath(), 1000, 700);
imageView.setImageBitmap(image);
}
}
public boolean isExternalStorageWritable() {
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
return true;
}
return false;
}
public static Bitmap decodeSampledBitmapFromFile(String path, int reqWidth, int reqHeight)
{ // BEST QUALITY MATCH
//First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(path, options);
// Calculate inSampleSize, Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
options.inPreferredConfig = Bitmap.Config.RGB_565;
int inSampleSize = 1;
if (height > reqHeight)
{
inSampleSize = Math.round((float)height / (float)reqHeight);
}
int expectedWidth = width / inSampleSize;
if (expectedWidth > reqWidth)
{
//if(Math.round((float)width / (float)reqWidth) > inSampleSize) // If bigger SampSize..
inSampleSize = Math.round((float)width / (float)reqWidth);
}
options.inSampleSize = inSampleSize;
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(path, options);
}
public void capture_btn(View v) {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
File file = new File(Environment.getExternalStorageDirectory() + File.separator + "image.jpg");
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file));
startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
}
}
Android清单
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.matts.myapplication" >
<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"/>
<uses-feature android:name="android.hardware.camera"/>
<uses-feature android:name="android.hardware.camera.autofocus"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="@string/app_name"
android:screenOrientation="portrait"
android:theme="@android:style/Theme.Black.NoTitleBar.Fullscreen" >
</activity>
<!-- Splash screen -->
<activity
android:name=".SplashScreen"
android:label="@string/app_name"
android:screenOrientation="portrait"
android:theme="@android:style/Theme.Black.NoTitleBar.Fullscreen" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
答案 0 :(得分：3)
将这些行移到<application>标记之外（上方）。
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-feature android:name="android.hardware.camera"/>
<uses-feature android:name="android.hardware.camera.autofocus"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
答案 1 :(得分：0)
我认为你不应该对use-permission标签进行分组/包装/堆叠。见http://developer.android.com/guide/topics/manifest/uses-permission-element.html
这样做：
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />