如果您想要以Gmail为目标，那么您可以执行以下操作。注意，意图是“ACTION_SENDTO”而不是“ACTION_SEND”，额外的意图字段对于Gmail是不必要的。

String uriText =
    "mailto:youremail@gmail.com" + 
    "?subject=" + Uri.encode("your subject line here") + 
    "&body=" + Uri.encode("message body here");

Uri uri = Uri.parse(uriText);

Intent sendIntent = new Intent(Intent.ACTION_SENDTO);
sendIntent.setData(uri);
if (sendIntent.resolveActivity(getPackageManager()) != null) {
   startActivity(Intent.createChooser(sendIntent, "Send message")); 
}

终于想出了最好的办法

String to = "test@gmail.com";
String subject= "Hi I am subject";
String body="Hi I am test body";
String mailTo = "mailto:" + to +
        "?&subject=" + Uri.encode(subject) +
        "&body=" + Uri.encode(body);
Intent emailIntent = new Intent(Intent.ACTION_VIEW);
emailIntent.setData(Uri.parse(mailTo));
startActivity(emailIntent);

下面的代码对我来说很好。

Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("message/rfc822");
intent.putExtra(Intent.EXTRA_SUBJECT, subject);
intent.putExtra(Intent.EXTRA_EMAIL, new String[]{"abc@gmailcom"});
Intent mailer = Intent.createChooser(intent, null);
startActivity(mailer);

适用于所有android版本:

String[] to = {"email@server.com"};
Uri uri = Uri.parse("mailto:email@server.com")
  .buildUpon()
  .appendQueryParameter("subject", "subject")
  .appendQueryParameter("body", "body")
  .build();
Intent emailIntent = new Intent(ACTION_SENDTO, uri);
emailIntent.putExtra(EXTRA_EMAIL, TO);
startActivity(Intent.createChooser(emailIntent, "Send mail..."));

更新到Android 10，现在使用Kotlin…

fun Context.sendEmail(
  address: String?,
  subject: String?,
  body: String?,
) {
  val recipients = arrayOf(address)
  val uri = address.toUri()
    .buildUpon()
    .appendQueryParameter("subject", subject)
    .appendQueryParameter("body", body)
    .build()
  val emailIntent = Intent(ACTION_SENDTO, uri).apply {
    setData("mailto:$address".toUri());
    putExtra(EXTRA_SUBJECT, subject);
    putExtra(EXTRA_TEXT, body);
    putExtra(EXTRA_EMAIL, recipients)
  }
  val pickerTitle = getString(R.string.some_title)
  ContextCompat.startActivity(this, Intent.createChooser(emailIntent, pickerTitle, null)
}

.．.在更新到API 30之后，代码没有填充电子邮件客户端的主题和主体(例如Gmail)。但我在这里找到了答案:

fun Context.sendEmail(
  address: String?,
  subject: String?,
  body: String?,
) {
  val selectorIntent = Intent(ACTION_SENDTO)
    .setData("mailto:$address".toUri())
  val emailIntent = Intent(ACTION_SEND).apply {
    putExtra(EXTRA_EMAIL, arrayOf(address))
    putExtra(EXTRA_SUBJECT, subject)
    putExtra(EXTRA_TEXT, body)
    selector = selectorIntent
  }
  startActivity(Intent.createChooser(emailIntent, getString(R.string.send_email))) 

}

根据Android开发者官方文档，这是发送电子邮件意图的正确方式

添加以下代码行到你的应用程序:

Intent intent = new Intent(Intent.ACTION_SEND);//common intent 
intent.setData(Uri.parse("mailto:")); // only email apps should handle this

可选:添加主体和主题，就像这样

intent.putExtra(Intent.EXTRA_SUBJECT, "Your Subject Here");
intent.putExtra(Intent.EXTRA_TEXT, "E-mail body" );

你的问题里已经加了这句话

intent.putExtra(Intent.EXTRA_EMAIL, new String[]{"hello@example.com"});

这将是收件人的地址，这意味着用户将向您(开发人员)发送电子邮件。

这些解决方案对我都不起作用。这里有一个对棒棒糖有效的最小解决方案。在我的设备上，只有Gmail和本地电子邮件应用程序出现在最终的选择器列表中。

Intent emailIntent = new Intent(Intent.ACTION_SENDTO,
                                Uri.parse("mailto:" + Uri.encode(address)));

emailIntent.putExtra(Intent.EXTRA_SUBJECT, subject);
emailIntent.putExtra(Intent.EXTRA_TEXT, body);
startActivity(Intent.createChooser(emailIntent, "Send email via..."));