我只想从相机拍摄照片并将其设置为ImageView。我关注了developer.android上的文档。当我单击按钮时，当我捕获图像并标记为“确定”时，它会在模拟器上打开仿真
进程：projectname.glob.projectname，PID：11771 java.lang.RuntimeException：无法将结果ResultInfo {who = null，request = 1，result = -1，data = Intent {}}传递到活动{projectname.glob.projectname / projectname.glob.projectname.MainActivity}：Java。 lang.NullPointerException：尝试在空对象引用上调用虚拟方法'java.lang.Object android.os.Bundle.get（java.lang.String）' 在android.app.ActivityThread.deliverResults（ActivityThread.java:4323） 在android.app.ActivityThread.handleSendResult（ActivityThread.java:4366） 在android.app.ActivityThread.-wrap19（未知来源：0） 在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1649） 在android.os.Handler.dispatchMessage（Handler.java:105） 在android.os.Looper.loop（Looper.java:164） 在android.app.ActivityThread.main（ActivityThread.java:6540） 在java.lang.reflect.Method.invoke（本机方法） 在com.android.internal.os.Zygote $ MethodAndArgsCaller.run（Zygote.java:240） 在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:767） 原因：java.lang.NullPointerException：尝试在空对象引用上调用虚拟方法'java.lang.Object android.os.Bundle.get（java.lang.String）' 在projectname.becse.kit.projectname.MainActivity.onActivityResult（MainActivity.java:91） 在android.app.Activity.dispatchActivityResult（Activity.java:7237） 在android.app.ActivityThread.deliverResults（ActivityThread.java:4319）
我的代码： MainActivity
package projectname.glob.projectname;
import android.Manifest;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.annotation.NonNull;
import android.support.annotation.RequiresApi;
import android.support.v4.content.FileProvider;
import android.support.v7.app.AlertDialog;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class MainActivity extends Activity {
String mCurrentPhotoPath;
static final int REQUEST_TAKE_PHOTO = 1;
ImageView mImageView;
Button btn_takePhoto;
private String[] permissions = {Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.CAMERA, Manifest.permission.READ_SMS};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.first_layout);
mImageView=(ImageView)findViewById(R.id.imgv);
btn_takePhoto=(Button)findViewById(R.id.btn_takePhoto);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if(arePermissionsEnabled()){
Toast.makeText(MainActivity.this,"All Permission Granted",Toast.LENGTH_LONG).show();
}else{
requestMultiplePermissions();
}
}
btn_takePhoto.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
dispatchTakePictureIntent();
}
});
}
private void dispatchTakePictureIntent() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// Ensure that there's a camera activity to handle the intent
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
// Create the File where the photo should go
File photoFile = null;
try {
photoFile = createImageFile();
} catch (IOException ex) {
// Error occurred while creating the File
Toast.makeText(MainActivity.this,"Device Not Able To Create File",Toast.LENGTH_LONG).show();
}
// Continue only if the File was successfully created
if (photoFile != null) {
Uri photoURI = FileProvider.getUriForFile(this,
"projectname.glob.projectname.MainActivity",
photoFile);
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
}
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_TAKE_PHOTO && resultCode == RESULT_OK && data!=null) {
Bundle extras = data.getExtras();
Bitmap imageBitmap = (Bitmap) extras.get("data");
mImageView.setImageBitmap(imageBitmap);
}
}
private File createImageFile() throws IOException {
// Create an image file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_" + timeStamp + "_";
File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
File image = File.createTempFile(
imageFileName, /* prefix */
".jpg", /* suffix */
storageDir /* directory */
);
// Save a file: path for use with ACTION_VIEW intents
mCurrentPhotoPath = image.getAbsolutePath();
return image;
}
/*********************Permission Releted Work**************************/
@RequiresApi(api = Build.VERSION_CODES.M)
private boolean arePermissionsEnabled(){
for(String permission : permissions){
if(checkSelfPermission(permission) != PackageManager.PERMISSION_GRANTED)
return false;
}
return true;
}
@RequiresApi(api = Build.VERSION_CODES.M)
private void requestMultiplePermissions(){
List<String> remainingPermissions = new ArrayList<>();
for (String permission : permissions) {
if (checkSelfPermission(permission) != PackageManager.PERMISSION_GRANTED) {
remainingPermissions.add(permission);
}
}
requestPermissions(remainingPermissions.toArray(new String[remainingPermissions.size()]), 101);
}
@TargetApi(Build.VERSION_CODES.M)
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if(requestCode == 101){
for(int i=0;i<grantResults.length;i++){
if(grantResults[i] != PackageManager.PERMISSION_GRANTED){
if(shouldShowRequestPermissionRationale(permissions[i])){
new AlertDialog.Builder(this)
.setMessage("We are taking some permisson just to access data locally ")
.setPositiveButton("Allow", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
requestMultiplePermissions();
}
})
.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
})
.create()
.show();
}
return;
}
}
//all is good, continue flow
}
}
/*********************Permission Releted Work**************************/
}
清单文件
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="projectname.glob.projectname">
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_SMS"/>
<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">
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="projectname.glob.projectname.MainActivity"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths"></meta-data>
</provider>
<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>
我在哪里定义路径的XML
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path name="my_images" path="Android/data/projectname.glob.projectname/files/Pictures" />
</paths>
可能存在一些愚蠢的错误，但我无法弄清楚！
答案 0 :(得分：0)
Bundle bundle = getIntent().getExtras();
if (bundle != null)
{
Bitmap imageBitmap = (Bitmap) extras.get("data");
mImageView.setImageBitmap(imageBitmap);
}