Media Recorder 示例应用程序崩溃 - 为什么会这样？
Media Recorder example app crashes - why so?
我尝试 运行 一个例子来用 Android 中的相机记录，但它崩溃了，控制台中显示的错误没有给我一个有效的错误来帮助我理解发生了什么.
我会向您展示代码，所以如果有人可以帮助我理解应用程序崩溃的原因。
在 activity_main.xml 中只有 2 个按钮调用功能开始和停止录制。
import java.io.IOException;
import android.app.Activity;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Intent;
import android.media.MediaRecorder;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity {
MediaRecorder recorder;
File audiofile = null;
static final String TAG = "MediaRecording";
Button startButton,stopButton;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
isStoragePermissionGranted();
startButton = (Button) findViewById(R.id.button1);
stopButton = (Button) findViewById(R.id.button2);
}
public boolean isStoragePermissionGranted() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
== PackageManager.PERMISSION_GRANTED) {
Log.v(TAG,"Permission is granted");
} else {
Log.v(TAG,"Permission is revoked");
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
}
}
else { //permission is automatically granted on sdk<23 upon installation
Log.v(TAG,"Permission is granted");
}
}
public void startRecording(View view) throws IOException {
startButton.setEnabled(false);
stopButton.setEnabled(true);
//Creating file
File dir = Environment.getExternalStorageDirectory();
try {
audiofile = File.createTempFile("sound", ".3gp", dir);
} catch (IOException e) {
Log.e(TAG, "external storage access error");
return;
}
//Creating MediaRecorder and specifying audio source, output format, encoder & output format
recorder = new MediaRecorder();
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recorder.setOutputFile(audiofile.getAbsolutePath());
recorder.prepare();
recorder.start();
}
public void stopRecording(View view) {
startButton.setEnabled(true);
stopButton.setEnabled(false);
//stopping recorder
recorder.stop();
recorder.release();
//after stopping the recorder, create the sound file and add it to media library.
addRecordingToMediaLibrary();
}
protected void addRecordingToMediaLibrary() {
//creating content values of size 4
ContentValues values = new ContentValues(4);
long current = System.currentTimeMillis();
values.put(MediaStore.Audio.Media.TITLE, "audio" + audiofile.getName());
values.put(MediaStore.Audio.Media.DATE_ADDED, (int) (current / 1000));
values.put(MediaStore.Audio.Media.MIME_TYPE, "audio/3gpp");
values.put(MediaStore.Audio.Media.DATA, audiofile.getAbsolutePath());
//creating content resolver and storing it in the external content uri
ContentResolver contentResolver = getContentResolver();
Uri base = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
Uri newUri = contentResolver.insert(base, values);
//sending broadcast message to scan the media file so that it can be available
sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, newUri));
Toast.makeText(this, "Added File " + newUri, Toast.LENGTH_LONG).show();
}
我在Logcat中添加了错误，以帮助您
07-25 17:51:16.244 20019-20019/com.example.decoding E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.decoding, PID: 20019
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.view.View$DeclaredOnClickListener.onClick(View.java:4740)
at android.view.View.performClick(View.java:5697)
at android.widget.TextView.performClick(TextView.java:10826)
at android.view.View$PerformClick.run(View.java:22526)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at android.view.View$DeclaredOnClickListener.onClick(View.java:4735)
at android.view.View.performClick(View.java:5697)
at android.widget.TextView.performClick(TextView.java:10826)
at android.view.View$PerformClick.run(View.java:22526)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: java.lang.RuntimeException: setAudioSource failed.
at android.media.MediaRecorder._setAudioSource(Native Method)
at android.media.MediaRecorder.setAudioSource(MediaRecorder.java:488)
at com.example.decoding.MainActivity.startRecording(MainActivity.java:46)
at java.lang.reflect.Method.invoke(Native Method)
at android.view.View$DeclaredOnClickListener.onClick(View.java:4735)
at android.view.View.performClick(View.java:5697)
at android.widget.TextView.performClick(TextView.java:10826)
at android.view.View$PerformClick.run(View.java:22526)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
```
打开您的 android 清单并添加此行：
<uses-permission android:name="android.permission.RECORD_AUDIO" />
为了将来参考，这是您 logcat:
的相关部分
Caused by: java.lang.RuntimeException: setAudioSource failed.
at android.media.MediaRecorder._setAudioSource(Native Method)
at android.media.MediaRecorder.setAudioSource(MediaRecorder.java:488)
at com.example.decoding.MainActivity.startRecording(MainActivity.java:46)
通过编程方式请求权限解决，即使是 Mic，这里是代码：
public void isStoragePermissionGranted() {
if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) {
}
// Else ask for permission
else {
ActivityCompat.requestPermissions(MainActivity.this, new String[]
{ Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.RECORD_AUDIO}, 0);
}
}
我尝试 运行 一个例子来用 Android 中的相机记录，但它崩溃了，控制台中显示的错误没有给我一个有效的错误来帮助我理解发生了什么. 我会向您展示代码，所以如果有人可以帮助我理解应用程序崩溃的原因。 在 activity_main.xml 中只有 2 个按钮调用功能开始和停止录制。
import java.io.IOException;
import android.app.Activity;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Intent;
import android.media.MediaRecorder;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity {
MediaRecorder recorder;
File audiofile = null;
static final String TAG = "MediaRecording";
Button startButton,stopButton;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
isStoragePermissionGranted();
startButton = (Button) findViewById(R.id.button1);
stopButton = (Button) findViewById(R.id.button2);
}
public boolean isStoragePermissionGranted() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
== PackageManager.PERMISSION_GRANTED) {
Log.v(TAG,"Permission is granted");
} else {
Log.v(TAG,"Permission is revoked");
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
}
}
else { //permission is automatically granted on sdk<23 upon installation
Log.v(TAG,"Permission is granted");
}
}
public void startRecording(View view) throws IOException {
startButton.setEnabled(false);
stopButton.setEnabled(true);
//Creating file
File dir = Environment.getExternalStorageDirectory();
try {
audiofile = File.createTempFile("sound", ".3gp", dir);
} catch (IOException e) {
Log.e(TAG, "external storage access error");
return;
}
//Creating MediaRecorder and specifying audio source, output format, encoder & output format
recorder = new MediaRecorder();
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recorder.setOutputFile(audiofile.getAbsolutePath());
recorder.prepare();
recorder.start();
}
public void stopRecording(View view) {
startButton.setEnabled(true);
stopButton.setEnabled(false);
//stopping recorder
recorder.stop();
recorder.release();
//after stopping the recorder, create the sound file and add it to media library.
addRecordingToMediaLibrary();
}
protected void addRecordingToMediaLibrary() {
//creating content values of size 4
ContentValues values = new ContentValues(4);
long current = System.currentTimeMillis();
values.put(MediaStore.Audio.Media.TITLE, "audio" + audiofile.getName());
values.put(MediaStore.Audio.Media.DATE_ADDED, (int) (current / 1000));
values.put(MediaStore.Audio.Media.MIME_TYPE, "audio/3gpp");
values.put(MediaStore.Audio.Media.DATA, audiofile.getAbsolutePath());
//creating content resolver and storing it in the external content uri
ContentResolver contentResolver = getContentResolver();
Uri base = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
Uri newUri = contentResolver.insert(base, values);
//sending broadcast message to scan the media file so that it can be available
sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, newUri));
Toast.makeText(this, "Added File " + newUri, Toast.LENGTH_LONG).show();
}
我在Logcat中添加了错误，以帮助您
07-25 17:51:16.244 20019-20019/com.example.decoding E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.decoding, PID: 20019
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.view.View$DeclaredOnClickListener.onClick(View.java:4740)
at android.view.View.performClick(View.java:5697)
at android.widget.TextView.performClick(TextView.java:10826)
at android.view.View$PerformClick.run(View.java:22526)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at android.view.View$DeclaredOnClickListener.onClick(View.java:4735)
at android.view.View.performClick(View.java:5697)
at android.widget.TextView.performClick(TextView.java:10826)
at android.view.View$PerformClick.run(View.java:22526)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: java.lang.RuntimeException: setAudioSource failed.
at android.media.MediaRecorder._setAudioSource(Native Method)
at android.media.MediaRecorder.setAudioSource(MediaRecorder.java:488)
at com.example.decoding.MainActivity.startRecording(MainActivity.java:46)
at java.lang.reflect.Method.invoke(Native Method)
at android.view.View$DeclaredOnClickListener.onClick(View.java:4735)
at android.view.View.performClick(View.java:5697)
at android.widget.TextView.performClick(TextView.java:10826)
at android.view.View$PerformClick.run(View.java:22526)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
```
打开您的 android 清单并添加此行：
<uses-permission android:name="android.permission.RECORD_AUDIO" />
为了将来参考，这是您 logcat:
的相关部分Caused by: java.lang.RuntimeException: setAudioSource failed.
at android.media.MediaRecorder._setAudioSource(Native Method)
at android.media.MediaRecorder.setAudioSource(MediaRecorder.java:488)
at com.example.decoding.MainActivity.startRecording(MainActivity.java:46)
通过编程方式请求权限解决，即使是 Mic，这里是代码：
public void isStoragePermissionGranted() {
if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) {
}
// Else ask for permission
else {
ActivityCompat.requestPermissions(MainActivity.this, new String[]
{ Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.RECORD_AUDIO}, 0);
}
}