Android Studio MediaRecorder 不会录制
Android Studio MediaRecorder won't record
我想在 android 工作室制作录音机。我遵循了本教程：
https://www.youtube.com/watch?v=XANjoeEeQ1Y
哪个不适合我？当我按下 "record" 按钮时，没有任何反应。
由此我添加了带有 onClick() 方法等的动作侦听器。仍然没有用。然后我添加了一个文本视图来显示调试状态。
添加状态文本视图后，我发现 beginRecording() 方法直接进入 catch 语句。
我看了另一个 youtube 视频
https://www.youtube.com/watch?v=lWaypoRVfSc
这似乎或多或少地对 MediaRecorder 做了同样的事情。
所以..我的问题是。我做错了什么？我怎样才能让它在按下录音按钮时真正录音？
提前谢谢你。
这是我的代码：
package com.example.natalie.recorder;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.TextView;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
public class MainActivity extends AppCompatActivity {
private MediaPlayer mediaPLayer;
private MediaRecorder recorder;
private String OUTPUT_FILE;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
Button startR = (Button) findViewById(R.id.startBtn);
Button stopR = (Button) findViewById(R.id.finishBtn);
Button playRecording = (Button) findViewById(R.id.playBtn);
Button stopPlaying = (Button) findViewById(R.id.stopBtn);
final TextView statusTV;
statusTV = (TextView) findViewById(R.id.statusTextView);
OUTPUT_FILE= Environment.getExternalStorageDirectory().getAbsolutePath()+"/audiorecorder.3gpp";
/*------START BUTTON------*/
startR.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View view) {
final TextView stv=statusTV;
try {
beginRecording();
stv.setText("Recording");
} catch (Exception e) {
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
String exceptionAsString = sw.toString();
stv.setText("Error");
}
}
});
/*------STOP BUTTON------*/
stopR.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View view) {
final TextView stv=statusTV;
try {
stopRecording();
stv.setText("Stopped");
} catch (Exception e) {
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
String exceptionAsString = sw.toString();
statusTV.setText("Error");
Log.d("here","dd",e);
}
}
});
playRecording.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View view) {
try {
playRecording();
} catch (Exception e) {
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
String exceptionAsString = sw.toString();
statusTV.setText("Error");
}
}
});
stopPlaying.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View view) {
try {
stopPlayback();
} catch (Exception e) {
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
String exceptionAsString = sw.toString();
statusTV.setText("Error");
}
}
});
}
private void stopPlayback() throws Exception{
if(mediaPLayer != null)
mediaPLayer.stop();
}
private void playRecording() throws IOException {
ditchMediaPLayer();
mediaPLayer = new MediaPlayer();
mediaPLayer.setDataSource(OUTPUT_FILE);
mediaPLayer.prepare();
mediaPLayer.start();
}
private void ditchMediaPLayer() {
if (mediaPLayer != null) {
try{
mediaPLayer.release();
} catch(Exception e) {
e.printStackTrace();
}
}
}
private void stopRecording() {
if(recorder != null)
recorder.stop();
}
private void beginRecording() throws Exception{
ditchMediaRecorder();
File outFile = new File(OUTPUT_FILE);
if (outFile.exists()) {
outFile.delete();
}
recorder = new MediaRecorder();
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
record.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recorder.setOutputFile(OUTPUT_FILE);
recorder.prepare();
recorder.start();
}
private void ditchMediaRecorder() {
if(recorder != null)
recorder.release();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
AndroidManifest 如下所示：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.natalie.recorder">
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-permission android:name="android.permission.RECORD_AUDIO"
/>
<uses-permission
android:name="android.permission.WRITE_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"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category
android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
content_main.xml来到这里：
<Button
android:id="@+id/stopBtn"
android:layout_width="249dp"
android:layout_height="56dp"
android:background="@color/colorAccent"
android:text="Stop PLayback"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/playBtn" />
<Button
android:id="@+id/playBtn"
android:layout_width="249dp"
android:layout_height="48dp"
android:background="@color/colorAccent"
android:text="Play Recording"
app:layout_constraintBottom_toTopOf="@+id/stopBtn"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/finishBtn" />
<Button
android:id="@+id/finishBtn"
android:layout_width="249dp"
android:layout_height="48dp"
android:background="@color/colorAccent"
android:text="Finish Recording"
app:layout_constraintBottom_toTopOf="@+id/playBtn"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/startBtn" />
<Button
android:id="@+id/startBtn"
android:layout_width="247dp"
android:layout_height="48dp"
android:background="@color/colorAccent"
android:text="Start Recording"
app:layout_constraintBottom_toTopOf="@+id/finishBtn"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/statusTextView"
android:layout_width="246dp"
android:layout_height="22dp"
android:text="Status"
android:textAlignment="center"
android:textSize="24sp"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintBottom_toTopOf="@+id/startBtn"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
您请求了 CAMERA、WRITE_STORAGE 和 RECORD_AUDIO 许可，但您并未在 activity 处请求。看看 this.
使用：
ContextCompat.checkSelfPermission(this,Manifest.permission.WRITE_EXTERNAL_STORAGE) 检查权限状态并将其与 PackageManager.PERMISSION_GRANTED 进行比较，这意味着您的权限已被接受，如下所示：
if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 100);
}
并在 onRequestPermissionsResult 中做这样的事情：
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//do work
}
}
我想在 android 工作室制作录音机。我遵循了本教程： https://www.youtube.com/watch?v=XANjoeEeQ1Y
哪个不适合我？当我按下 "record" 按钮时，没有任何反应。
由此我添加了带有 onClick() 方法等的动作侦听器。仍然没有用。然后我添加了一个文本视图来显示调试状态。
添加状态文本视图后，我发现 beginRecording() 方法直接进入 catch 语句。
我看了另一个 youtube 视频 https://www.youtube.com/watch?v=lWaypoRVfSc 这似乎或多或少地对 MediaRecorder 做了同样的事情。
所以..我的问题是。我做错了什么？我怎样才能让它在按下录音按钮时真正录音？
提前谢谢你。
这是我的代码：
package com.example.natalie.recorder;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.TextView;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
public class MainActivity extends AppCompatActivity {
private MediaPlayer mediaPLayer;
private MediaRecorder recorder;
private String OUTPUT_FILE;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
Button startR = (Button) findViewById(R.id.startBtn);
Button stopR = (Button) findViewById(R.id.finishBtn);
Button playRecording = (Button) findViewById(R.id.playBtn);
Button stopPlaying = (Button) findViewById(R.id.stopBtn);
final TextView statusTV;
statusTV = (TextView) findViewById(R.id.statusTextView);
OUTPUT_FILE= Environment.getExternalStorageDirectory().getAbsolutePath()+"/audiorecorder.3gpp";
/*------START BUTTON------*/
startR.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View view) {
final TextView stv=statusTV;
try {
beginRecording();
stv.setText("Recording");
} catch (Exception e) {
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
String exceptionAsString = sw.toString();
stv.setText("Error");
}
}
});
/*------STOP BUTTON------*/
stopR.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View view) {
final TextView stv=statusTV;
try {
stopRecording();
stv.setText("Stopped");
} catch (Exception e) {
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
String exceptionAsString = sw.toString();
statusTV.setText("Error");
Log.d("here","dd",e);
}
}
});
playRecording.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View view) {
try {
playRecording();
} catch (Exception e) {
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
String exceptionAsString = sw.toString();
statusTV.setText("Error");
}
}
});
stopPlaying.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View view) {
try {
stopPlayback();
} catch (Exception e) {
StringWriter sw = new StringWriter();
e.printStackTrace(new PrintWriter(sw));
String exceptionAsString = sw.toString();
statusTV.setText("Error");
}
}
});
}
private void stopPlayback() throws Exception{
if(mediaPLayer != null)
mediaPLayer.stop();
}
private void playRecording() throws IOException {
ditchMediaPLayer();
mediaPLayer = new MediaPlayer();
mediaPLayer.setDataSource(OUTPUT_FILE);
mediaPLayer.prepare();
mediaPLayer.start();
}
private void ditchMediaPLayer() {
if (mediaPLayer != null) {
try{
mediaPLayer.release();
} catch(Exception e) {
e.printStackTrace();
}
}
}
private void stopRecording() {
if(recorder != null)
recorder.stop();
}
private void beginRecording() throws Exception{
ditchMediaRecorder();
File outFile = new File(OUTPUT_FILE);
if (outFile.exists()) {
outFile.delete();
}
recorder = new MediaRecorder();
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
record.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recorder.setOutputFile(OUTPUT_FILE);
recorder.prepare();
recorder.start();
}
private void ditchMediaRecorder() {
if(recorder != null)
recorder.release();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
AndroidManifest 如下所示：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.natalie.recorder">
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-permission android:name="android.permission.RECORD_AUDIO"
/>
<uses-permission
android:name="android.permission.WRITE_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"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category
android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
content_main.xml来到这里：
<Button
android:id="@+id/stopBtn"
android:layout_width="249dp"
android:layout_height="56dp"
android:background="@color/colorAccent"
android:text="Stop PLayback"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/playBtn" />
<Button
android:id="@+id/playBtn"
android:layout_width="249dp"
android:layout_height="48dp"
android:background="@color/colorAccent"
android:text="Play Recording"
app:layout_constraintBottom_toTopOf="@+id/stopBtn"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/finishBtn" />
<Button
android:id="@+id/finishBtn"
android:layout_width="249dp"
android:layout_height="48dp"
android:background="@color/colorAccent"
android:text="Finish Recording"
app:layout_constraintBottom_toTopOf="@+id/playBtn"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@+id/startBtn" />
<Button
android:id="@+id/startBtn"
android:layout_width="247dp"
android:layout_height="48dp"
android:background="@color/colorAccent"
android:text="Start Recording"
app:layout_constraintBottom_toTopOf="@+id/finishBtn"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/statusTextView"
android:layout_width="246dp"
android:layout_height="22dp"
android:text="Status"
android:textAlignment="center"
android:textSize="24sp"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintBottom_toTopOf="@+id/startBtn"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
您请求了 CAMERA、WRITE_STORAGE 和 RECORD_AUDIO 许可，但您并未在 activity 处请求。看看 this.
使用：
ContextCompat.checkSelfPermission(this,Manifest.permission.WRITE_EXTERNAL_STORAGE) 检查权限状态并将其与 PackageManager.PERMISSION_GRANTED 进行比较，这意味着您的权限已被接受，如下所示：
if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 100);
}
并在 onRequestPermissionsResult 中做这样的事情：
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//do work
}
}