我只掌握有关android的基本知识。今天我开发了一个录音应用程序,但问题是用户可以录制音频,停止录音并且可以播放音频,但是当用户再次按下录音按钮播放后应用程序崩溃,任何人都可以帮助我吗?
这是我的主要活动
package com.hackerinside.jaisonjoseph.sample_recorder;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
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.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.Toast;
import java.io.IOException;
public class MainActivity extends AppCompatActivity {
private Button play,stop,record;
private MediaRecorder myAudioRecorder;
private String outputfile;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
play=(Button)findViewById(R.id.play);
stop=(Button)findViewById(R.id.stop);
record=(Button)findViewById(R.id.record);
stop.setEnabled(false);
play.setEnabled(false);
outputfile= Environment.getExternalStorageDirectory().getAbsolutePath()+"/recording_"+System.currentTimeMillis()+".mp3";
myAudioRecorder=new MediaRecorder();
myAudioRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
myAudioRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);
myAudioRecorder.setAudioEncoder(MediaRecorder.OutputFormat.DEFAULT);
myAudioRecorder.setOutputFile(outputfile);
record.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
try {
myAudioRecorder.prepare();
myAudioRecorder.start();
}
catch (IllegalStateException ise){
}catch (IOException ioe){
}
record.setEnabled(false);
stop.setEnabled(true);
Toast.makeText(getApplicationContext(),"record startded",Toast.LENGTH_LONG).show();
}
});
stop.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
myAudioRecorder.stop();
record.setEnabled(true);
myAudioRecorder.release();
myAudioRecorder=null;
stop.setEnabled(false);
play.setEnabled(true);
Toast.makeText(getApplicationContext(),"recorded audio",Toast.LENGTH_LONG).show();
}
});
play.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
MediaPlayer mediaPlayer=new MediaPlayer();
try {
mediaPlayer.setDataSource(outputfile);
mediaPlayer.prepare();
mediaPlayer.start();
Toast.makeText(getApplicationContext(),"playing audio",Toast.LENGTH_LONG).show();
}
catch (Exception e)
{
// here
}
}
});
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
@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);
}
}
答案 0 :(得分:3)
尝试添加此
myAudioRecorder=new MediaRecorder();
中的
record.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
try {
myAudioRecorder=new MediaRecorder();
myAudioRecorder.prepare();
myAudioRecorder.start();
}
或者,您可以从停止按钮单击中删除myAudioRecorder.release();
。
应该在活动的onPause()
期间发布
答案 1 :(得分:1)
这是因为,您在停止null
mediaRecorder
stop.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
myAudioRecorder.stop();
record.setEnabled(true);
myAudioRecorder.release();
myAudioRecorder=null;
stop.setEnabled(false);
play.setEnabled(true);
Toast.makeText(getApplicationContext(),"recorded audio",Toast.LENGTH_LONG).show();
}
});
当你再次点击记录时,这将被执行,
record.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
try {
// myAudioRecorder is null when you come up second time.
// Initialize myAudioRecorder to prevent an exception.
myAudioRecorder.prepare();
myAudioRecorder.start();
} catch (IllegalStateException ise){
} catch (IOException ioe) {
}
record.setEnabled(false);
stop.setEnabled(true);
Toast.makeText(getApplicationContext(),"record startded",Toast.LENGTH_LONG).show();
}
});
myAudioRecorder.prepare();
将通过NullPointerException
,myAudioRecorder
为null
。
虽然上面的代码在try.. catch
但你没有抓到NullPointerException
,但App会崩溃。
答案 2 :(得分:0)
如果你看documentations它表示你在发布录音机后无法访问录音机,这是你按停止时所做的事情,你必须实例化新的录音机或者只是不要;释放它。