为什么这个 Android 意图找不到电子邮件应用程序?

Why does this Android intent not find an email app?

我已经设置了电子邮件意图并尝试启动它。代码如下:

    public void emailSummary(String emailText, String name) {
        Intent emailIntent = new Intent(Intent.ACTION_SEND);
        emailIntent.setData(Uri.parse("mailto:"));
        emailIntent.putExtra(Intent.EXTRA_EMAIL, "");
        emailIntent.putExtra(Intent.EXTRA_SUBJECT, "JustJava order for " + name);
        emailIntent.putExtra(Intent.EXTRA_TEXT, emailText);
        Log.v("MainActivity", "Finished setting up intent");
        if (emailIntent.resolveActivity(getPackageManager()) != null) {
            startActivity(emailIntent);
            Log.v("MainActivity", "Sharing the order summary to email");
        } else {
            Log.d("MainActivity", "No email app installed!");
            Toast.makeText(MainActivity.this, "Uh...No email app?", Toast.LENGTH_SHORT).show();
        }

但是,当我按下“订购”按钮时,"Uh... No email app?" toast 出现了。我同时安装了收件箱和 Gmail,但 Intent 似乎没有找到它们。为什么?

您可以使用此代码:

Intent emailIntent = new Intent(Intent.ACTION_SENDTO, Uri.fromParts(
        "mailto",name, null));
emailIntent.putExtra(Intent.EXTRA_SUBJECT, "SOME_SUBJECT");
emailIntent.putExtra(Intent.EXTRA_TEXT, emailText);
try {
startActivity(Intent.createChooser(emailIntent, "Send email..."));
Log.v("MainActivity", "Sharing the order summary to email");
} 
catch (android.content.ActivityNotFoundException ex) {
Log.d("MainActivity", "No email app installed!");
Toast.makeText(MainActivity.this, "Uh...No email app?", Toast.LENGTH_SHORT).show();
}

can you please explain what was wrong with my code?

我已经测试了你的代码,if (emailIntent.resolveActivity(getPackageManager()) != null) {无法检查你的设备上是否有任何电子邮件应用程序。我找到了这个方法并且工作正常:@Nitin answer

public static boolean isMailClientPresent(Context context){
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("text/html");
final PackageManager packageManager = context.getPackageManager();
List<ResolveInfo> list = packageManager.queryIntentActivities(intent, 0);

if(list.size() == 0)
    return false;
else 
    return true;
}