我想将图像图标设置为JButton，这是我尝试过的代码：
public class Calculator {
public static JFrame f;
Calculator() throws IOException{
JButton b;
f = new JFrame();
Image play = ImageIO.read(getClass().getResource("images/play.png"));
b = new JButton(new ImageIcon(play));
b.setBounds(250,250,75,20);
f.add(b);
f.setSize(500,500);
f.setLayout(null);
f.setVisible(true);
}
public static void main(String[] args) throws IOException {
new Calculator();
}
}
程序正常运行且没有错误，但图像没有出现。
我认为图片网址错误。
我正在使用netbeans，所以我在源包目录中创建了一个名为images的文件夹。
答案 0 :(得分：1)
可以通过在资源路径前加斜杠来解决此问题：
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" ></uses-permission>
<uses-permission android:name="android.permission.RECORD_AUDIO" ></uses-permission>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" ></uses-permission>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" ></uses-permission>
<uses-permission android:name="android.permission.INTERNET" ></uses-permission>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" ></uses-permission>
这表示import java.io.File;
import java.io.IOException;
import java.sql.SQLOutput;
import java.util.ArrayList;
import java.util.Date;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.media.MediaRecorder;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.os.StrictMode;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.BasicResponseHandler;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import java.text.SimpleDateFormat;
import java.util.List;
public class MainActivity extends Activity {
public double longi1 = 0.0;
public double lati1 = 0.0;
public LocationListener locationListener ;
public TextView Longi1;
public TextView Lati1;
Button b1;
int cekbutton;
public String filename="";
SimpleDateFormat formatter = new SimpleDateFormat("yyyy_MM_dd_HH_mm_ss");
Date now = new Date();
String fileName = formatter.format(now);
private static final String AUDIO_RECORDER_FILE_EXT_AMR = ".amr";
private static final String AUDIO_RECORDER_FOLDER = "AudioRecorder";
private MediaRecorder recorder = null;
private int currentFormat = 0;
private int output_formats[] = {MediaRecorder.OutputFormat.RAW_AMR};
private String file_exts[] = {AUDIO_RECORDER_FILE_EXT_AMR};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if(Build.VERSION.SDK_INT > 9){
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
b1 = (Button) findViewById(R.id.button);
getlongilatifile();
b1.setOnClickListener(new View.OnClickListener(){
public void onClick(View v){
if(cekbutton==0)
{
cekbutton=1;
b1.setText("STOP");
startRecording();
}
else if(cekbutton==1)
{
stopRecording();
Intent i = new Intent(MainActivity.this,halaman2.class);
i.putExtra("nama", filename);
startActivity(i);
}
}
});
}
public void getlongilatifile(){
LocationManager locationManager =
(LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
String bestProvider = locationManager.getBestProvider(criteria, true);
Location location = locationManager.getLastKnownLocation(bestProvider);
Longi1= (TextView) findViewById(R.id.textView1);
Lati1= (TextView) findViewById(R.id.textView);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1, 1, new LocationListener() {
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
longi1 = location.getLongitude();
lati1 = location.getLatitude();
Longi1.setText(longi1+"");
Lati1.setText(lati1+"");
try {
DefaultHttpClient hc=new DefaultHttpClient();
ResponseHandler<String> res=new BasicResponseHandler();
HttpPost postMethod = new HttpPost("http://10.0.2.2:8080/send_malem_3.php");
System.out.printf("test setelah nyambung");
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("nama", fileName+".amr"));
postMethod.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response2 = hc.execute(postMethod);
}
catch (ClientProtocolException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
Toast.makeText(getBaseContext(), "Gagal 2", Toast.LENGTH_SHORT).show();
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
private void startRecording(){
recorder = new MediaRecorder();
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
recorder.setOutputFormat(output_formats[currentFormat]);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
getFilename();
recorder.setOutputFile(filename);
recorder.setOnErrorListener(errorListener);
recorder.setOnInfoListener(infoListener);
try {
recorder.prepare();
recorder.start();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private void getFilename(){
String filepath = Environment.getExternalStorageDirectory().getPath();
File file = new File(filepath,AUDIO_RECORDER_FOLDER);
if(!file.exists()){
file.mkdirs();
}
filename = (file.getAbsolutePath() + "/" + fileName + file_exts[currentFormat]);
}
private MediaRecorder.OnErrorListener errorListener = new MediaRecorder.OnErrorListener() {
@Override
public void onError(MediaRecorder mr, int what, int extra) {
AppLog.logString("Error: " + what + ", " + extra);
}
};
private MediaRecorder.OnInfoListener infoListener = new MediaRecorder.OnInfoListener() {
@Override
public void onInfo(MediaRecorder mr, int what, int extra) {
AppLog.logString("Warning: " + what + ", " + extra);
}
};
private void stopRecording(){
if(null != recorder){
recorder.stop();
recorder.reset();
recorder.release();
recorder = null;
}
}
文件夹位于所有资源的根位置，而不是相对于当前类位置。
积分部分转到Andrew Thompson的评论。
答案 1 :(得分：0)
尝试使用b.setIcon(new ImageIcon(getClass().getResource("images/play.png")));