我找到了这个例子http://android-codes-examples.blogspot.com/2011/11/show-or-hide-soft-keyboard-on-opening.html。在alert.show()之前添加以下代码。

InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.toggleSoftInput(InputMethodManager.SHOW_FORCED,0);

好吧，这是一个相当老的帖子，仍然有一些东西需要添加。这是两个简单的方法，帮助我保持键盘在控制之下，他们工作得非常完美:

显示键盘

public void showKeyboard() {
    InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    View v = getCurrentFocus();
    if (v != null)
        imm.showSoftInput(v, 0);
}

隐藏键盘

public void hideKeyboard() {
    InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    View v = getCurrentFocus();
    if (v != null)
        imm.hideSoftInputFromWindow(v.getWindowToken(), 0);
}

看看这个手动隐藏和显示IME的讨论。然而，我的感觉是，如果一个集中的EditText没有带来IME，这是因为你正在调用AlertDialog.show()在你的OnCreate()或一些其他方法，在屏幕实际呈现之前被唤起。移动到OnPostResume()应该在这种情况下修复它，我相信。

来自其他答案的代码片段也可以工作，但将它们放在代码中的哪个位置并不总是很明显，特别是在使用AlertDialog时。Builder和遵循官方对话框教程，因为它不使用最终AlertDialog…或alertDialog.show()。

alertDialog.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE);

更可取

InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.toggleSoftInput(InputMethodManager.SHOW_FORCED,0);

因为如果焦点从EditText移开，SOFT_INPUT_STATE_ALWAYS_VISIBLE将隐藏键盘，而SHOW_FORCED将保持键盘显示，直到显式地关闭，即使用户返回到主屏幕或显示最近的应用程序。

下面是使用自定义布局和XML定义的EditText创建的AlertDialog的工作代码。它还设置键盘有一个“go”键，并允许它触发积极按钮。

alert_dialog.xml:

<RelativeLayout
android:id="@+id/dialogRelativeLayout"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content" >

    <!-- android:imeOptions="actionGo" sets the keyboard to have a "go" key instead of a "new line" key. -->
    <!-- android:inputType="textUri" disables spell check in the EditText and changes the "go" key from a check mark to an arrow. -->
    <EditText
        android:id="@+id/editText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:layout_marginLeft="4dp"
        android:layout_marginRight="4dp"
        android:layout_marginBottom="16dp"
        android:imeOptions="actionGo"
        android:inputType="textUri"/>

</RelativeLayout>

AlertDialog.java:

import android.app.Activity;
import android.app.Dialog;
import android.content.DialogInterface;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.DialogFragment;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatDialogFragment;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.WindowManager;
import android.widget.EditText;

public class CreateDialog extends AppCompatDialogFragment {
    // The public interface is used to send information back to the activity that called CreateDialog.
    public interface CreateDialogListener {
        void onCreateDialogCancel(DialogFragment dialog);    
        void onCreateDialogOK(DialogFragment dialog);
    }

    CreateDialogListener mListener;

    // Check to make sure that the activity that called CreateDialog implements both listeners.
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        try {
            mListener = (CreateDialogListener) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString() + " must implement CreateDialogListener.");
        }
    }

    // onCreateDialog requires @NonNull.
    @Override
    @NonNull
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(getActivity());
        LayoutInflater customDialogInflater = getActivity().getLayoutInflater();

        // Setup dialogBuilder.
        alertDialogBuilder.setTitle(R.string.title);
        alertDialogBuilder.setView(customDialogInflater.inflate(R.layout.alert_dialog, null));
        alertDialogBuilder.setNegativeButton(R.string.cancel, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                mListener.onCreateDialogCancel(CreateDialog.this);
            }
        });
        alertDialogBuilder.setPositiveButton(R.string.ok, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                mListener.onCreateDialogOK(CreateDialog.this);
            }
        });

        // Assign the resulting built dialog to an AlertDialog.
        final AlertDialog alertDialog = alertDialogBuilder.create();

        // Show the keyboard when the dialog is displayed on the screen.
        alertDialog.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE);

        // We need to show alertDialog before we can setOnKeyListener below.
        alertDialog.show();

        EditText editText = (EditText) alertDialog.findViewById(R.id.editText);

        // Allow the "enter" key on the keyboard to execute "OK".
        editText.setOnKeyListener(new View.OnKeyListener() {
            public boolean onKey(View v, int keyCode, KeyEvent event) {
                // If the event is a key-down event on the "enter" button, select the PositiveButton "OK".
                if ((event.getAction() == KeyEvent.ACTION_DOWN) && (keyCode == KeyEvent.KEYCODE_ENTER)) {
                    // Trigger the create listener.
                    mListener.onCreateDialogOK(CreateDialog.this);

                    // Manually dismiss alertDialog.
                    alertDialog.dismiss();

                    // Consume the event.
                    return true;
                } else {
                    // If any other key was pressed, do not consume the event.
                    return false;
                }
            }
        });

        // onCreateDialog requires the return of an AlertDialog.
        return alertDialog;
    }
}

尝试了很多，但这对我来说是有效的(kotlin):

        val dialog = builder.create()
        dialog.setOnShowListener {
            nameEditText.requestFocus()
            val s = ContextCompat.getSystemService(requireContext(), InputMethodManager::class.java)
            s?.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0)
        }

        dialog.setOnDismissListener {
            val s = ContextCompat.getSystemService(requireContext(), InputMethodManager::class.java)
            s?.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY, 0)
        }

        dialog.show()

为什么这个答案-因为上面的解决方案将显示你的键盘，但它不会消失，如果你点击任何其他的编辑文本。因此，当EditText失去焦点时，您需要做一些事情使键消失。

你可以通过以下步骤来实现这一点:

Make the parent view(content view of your activity) clickable and focusable by adding the following attributes android:clickable="true" android:focusableInTouchMode="true" Implement a hideKeyboard() method public void hideKeyboard(View view) { InputMethodManager inputMethodManager =(InputMethodManager)getSystemService(Activity.INPUT_METHOD_SERVICE); inputMethodManager.hideSoftInputFromWindow(view.getWindowToken(),InputMethodManager.HIDE_IMPLICIT_ONLY ); } Lastly, set the onFocusChangeListener of your edittext. edittext.setOnFocusChangeListener(new View.OnFocusChangeListener() { @Override public void onFocusChange(View v, boolean hasFocus) { if (!hasFocus) { hideKeyboard(v); } } });