我知道这是一个丑陋的代码，但我不知道更好的方法。不能完全使用for循环，因为我们每次单击按钮时只拍摄一张照片。我怎样才能避免重复？
重复数字1：（拍照）
@Override
public void onClick(View view) {
Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
//Getting the date, minues & seconds
Date date = new Date();
DateFormat df = new SimpleDateFormat("MM-dd-hh-mm-ss");
if (picOne == null) {
picOne = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), picOne + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
} else if (picTwo == null) {
picTwo = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), picTwo + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
} else if (picThree == null) {
picThree = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), picThree + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
} else if (picFour == null) {
picFour = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), picFour + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
} else if (picFive == null) {
picFive = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), picFive + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
} else if (picSix == null) {
picSix = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), picSix + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
btnCamera.setEnabled(false);
}
//Starting Activity
startActivityForResult(intent, 19);
}
重复数字2：（将每张图片附加到电子邮件中）
private Message createMessage(String email, String subject, String messageBody, Session session) throws MessagingException, UnsupportedEncodingException {
Message message = new MimeMessage(session);
message.setFrom(new InternetAddress("josh@josh.com", "Josh Thompson"));
message.addRecipient(Message.RecipientType.TO, new InternetAddress(email, email));
message.setSubject(subject);
//Message
MimeBodyPart mbp1 = new MimeBodyPart();
mbp1.setText(messageBody);
//Blending
Multipart mp = new MimeMultipart();
mp.addBodyPart(mbp1);
if (picOne != null) {
MimeBodyPart mbpc1 = new MimeBodyPart();
FileDataSource source = new FileDataSource(getExternalFilesDir(null) + "/" + picOne + ".jpg");
mbpc1.setDataHandler(new DataHandler(source));
mbpc1.setFileName(picOne + ".jpg");
mp.addBodyPart(mbpc1);
}
if (picTwo != null) {
MimeBodyPart mbpc2 = new MimeBodyPart();
FileDataSource source = new FileDataSource(getExternalFilesDir(null) + "/" + picTwo + ".jpg");
mbpc2.setDataHandler(new DataHandler(source));
mbpc2.setFileName(picTwo + ".jpg");
mp.addBodyPart(mbpc2);
}
if (picThree != null) {
MimeBodyPart mbpc3 = new MimeBodyPart();
FileDataSource source = new FileDataSource(getExternalFilesDir(null) + "/" + picThree + ".jpg");
mbpc3.setDataHandler(new DataHandler(source));
mbpc3.setFileName(picThree + ".jpg");
mp.addBodyPart(mbpc3);
}
if (picFour != null) {
MimeBodyPart mbpc4 = new MimeBodyPart();
FileDataSource source = new FileDataSource(getExternalFilesDir(null) + "/" + picFour + ".jpg");
mbpc4.setDataHandler(new DataHandler(source));
mbpc4.setFileName(picFour + ".jpg");
mp.addBodyPart(mbpc4);
}
if (picFive != null) {
MimeBodyPart mbpc5 = new MimeBodyPart();
FileDataSource source = new FileDataSource(getExternalFilesDir(null) + "/" + picFive + ".jpg");
mbpc5.setDataHandler(new DataHandler(source));
mbpc5.setFileName(picFive + ".jpg");
mp.addBodyPart(mbpc5);
}
if (picSix != null) {
MimeBodyPart mbpc6 = new MimeBodyPart();
FileDataSource source = new FileDataSource(getExternalFilesDir(null) + "/" + picSix + ".jpg");
mbpc6.setDataHandler(new DataHandler(source));
mbpc6.setFileName(picSix + ".jpg");
mp.addBodyPart(mbpc6);
}
message.setContent(mp);
return message;
}
如您所见，重复数字2 有点棘手。对于重复数字1 ，我们可以使用String pic[] = new String[7]，每次按下按钮，我们可以在全局int变量上添加+1，就像我在下面尝试的那样。
n = n+1;
pic[n] = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), pic[n] + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
if (n == 6) {
btnCamera.setEnabled(false);
}
但是，我尝试将MimeBodyPart mbpc[] = new MimeBodyPart[7]与for循环一起使用，如下所示：
for (int i = 0; i < 6; i++) {
FileDataSource source = new FileDataSource(getExternalFilesDir(null) + "/" + pic[i] + ".jpg");
mbpc[i].setDataHandler(new DataHandler(source));
mbpc[i].setFileName(pic[i] + ".jpg");
mp.addBodyPart(mbpc[i]);
}
如果我尝试运行上面的代码，应用程序崩溃，我收到以下错误：
12-27 05:04:26.586 17771-17771/gsi.againmail E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: gsi.againmail, PID: 17771
java.lang.NullPointerException: Attempt to invoke virtual method 'void javax.mail.internet.MimeBodyPart.setDataHandler(javax.activation.DataHandler)' on a null object reference
at gsi.againmail.MainActivity.createMessage(MainActivity.java:183)
at gsi.againmail.MainActivity.sendMail(MainActivity.java:146)
at gsi.againmail.MainActivity.access$300(MainActivity.java:39)
at gsi.againmail.MainActivity$1.onClick(MainActivity.java:75)
at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19749)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
另一个问题是pic [i]即将出现：
12-27 05:07:51.748 18591-18774/gsi.againmail W/System.err﹕ java.io.FileNotFoundException: /storage/emulated/0/Android/data/gsi.againmail/files/null.jpg: open failed: ENOENT (No such file or directory)
12-27 05:07:51.748 18591-18774/gsi.againmail W/System.err﹕ at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:676)
答案 0 :(得分：1)
这是一个例子;
if (picOne == null) {
picOne = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), picOne + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
} else if (picTwo == null) {
picTwo = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), picTwo + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
} else if (picThree == null) {
picThree = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), picThree + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
} else if (picFour == null) {
picFour = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), picFour + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
} else if (picFive == null) {
picFive = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), picFive + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
} else if (picSix == null) {
picSix = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), picSix + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
btnCamera.setEnabled(false);
}
可以使用像loadPhoto
private String loadPhoto() {
Date date = new Date();
DateFormat df = new SimpleDateFormat("MM-dd-hh-mm-ss");
String str = "gsiDoc-" + df.format(date);
File photo = new File(getExternalFilesDir(null), str + ".jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
return str;
}
然后
if (picOne == null) {
picOne = loadPhoto();
} else if (picTwo == null) {
picTwo = loadPhoto();
} else if (picThree == null) {
picThree = loadPhoto();
} else if (picFour == null) {
picFour = loadPhoto();
} else if (picFive == null) {
picFive = loadPhoto();
} else if (picSix == null) {
picSix = loadPhoto();
btnCamera.setEnabled(false);
}
然后，如果您在阵列中拥有pic（s），则可以使用类似
String[] arr = { picOne, picTwo, picThree, picFour, picFive, picSix };
for (int i = 0; i < arr.length; i++) {
if (arr[i] == null) {
arr[i] = loadPhoto();
if (i == arr.length - 1) {
btnCamera.setEnabled(false);
}
}
}