这有点棘手。我这样做了，而且成功了。

1.在第一次调用时，从窗口中隐藏软输入。如果软键盘可见，这将隐藏软输入;如果软键盘不可见，则不执行任何操作。

2.展示你的对话

3.然后简单地调用切换软输入。

代码:

InputMethodManager inputManager = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE); 
//hiding soft input
inputManager.hideSoftInputFromWindow(findViewById(android.R.id.content).getWind‌​owToken(), 0);
//show dialog
yourDialog.show();
//toggle soft input
inputManager.toggleSoftInput(InputMethodManager.SHOW_FORCED,InputMethodManager.SHOW_IMPLICIT);

这有点棘手。我这样做了，而且成功了。

1.在第一次调用时，从窗口中隐藏软输入。如果软键盘可见，这将隐藏软输入;如果软键盘不可见，则不执行任何操作。

2.展示你的对话

3.然后简单地调用切换软输入。

代码:

InputMethodManager inputManager = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE); 
//hiding soft input
inputManager.hideSoftInputFromWindow(findViewById(android.R.id.content).getWind‌​owToken(), 0);
//show dialog
yourDialog.show();
//toggle soft input
inputManager.toggleSoftInput(InputMethodManager.SHOW_FORCED,InputMethodManager.SHOW_IMPLICIT);

我知道这个问题很老了，因为我认为使用扩展函数是一种更漂亮的方式来显示编辑文本的键盘

下面是我用来显示编辑文本键盘的方法。

芬兰湾的科特林代码: 只需要调用edittext.showKeyboard()

fun EditText.showKeyboard() {
  post {
    requestFocus()
    val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    imm.showSoftInput(this, InputMethodManager.SHOW_IMPLICIT)
  }
}

Java代码:

public static void showKeyboard(EditText editText) {
    editText.post(new Runnable() {
      @Override
      public void run() {
        editText.requestFocus();
        InputMethodManager imm = (InputMethodManager) editText.getContext()
            .getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.showSoftInput(editText, InputMethodManager.SHOW_IMPLICIT);
      }
    });
  }

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;
    }
}

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

我在onCreate()中调用它来自动显示键盘，当我进入活动时。

只需将这一行添加到manifest文件必要的活动。

android：windowSoftInputMode=“stateVisible”