如果有人想:

不能从Activity类型对非静态方法getSystemService(String)进行静态引用

尝试向getSystemService调用添加上下文。

So

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

这是一个很好的例子:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ScrollView
        android:id="@+id/scrollID"
        android:layout_width="fill_parent"
        android:layout_height="0dip"
        android:layout_weight="1" >

        <LinearLayout
            android:id="@+id/test"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical" >
        </LinearLayout>
    </ScrollView>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:baselineAligned="true"
        android:orientation="horizontal"
        android:paddingBottom="5dp"
        android:paddingLeft="5dp"
        android:paddingRight="5dp"
        android:weightSum="1" >

        <EditText
            android:id="@+id/txtInpuConversation"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="0.5"
            android:hint="@string/edt_Conversation" >

            <requestFocus />
        </EditText>

        <Button
            android:id="@+id/btnSend"
            android:layout_width="0dip"
            android:layout_height="wrap_content"
            android:layout_weight="0.5"
            android:text="@string/btn_Conversation" />
    </LinearLayout>

</LinearLayout>

最初的问题涉及对话框和我的EditText是常规视图。无论如何，我认为这对你们大多数人也适用。所以这是对我有效的方法(上面建议的最高评价的方法对我没有任何作用)。下面是一个自定义的EditView，它可以做到这一点(子类化不是必需的，但我发现这对我的目的很方便，因为我还想在视图可见时捕获焦点)。

This is actually largely the same as the tidbecks answer. I actually didn't notice his answer at all as it had zero up votes. Then I was about to just comment his post, but it would have been too long, so I ended doing this post anyways. tidbeck points out that he's unsure how it works with devices having keyboards. I can confirm that the behaviour seems to be exactly the same in either case. That being such that on portrait mode the software keyboard gets popped up and on landscape it doesn't. Having the physical keyboard slid out or not makes no difference on my phone.

因为，我个人觉得行为有点尴尬，我选择使用:InputMethodManager.SHOW_FORCED。这是我想要的效果。无论朝向如何，键盘都是可见的，然而，至少在我的设备上，如果硬件键盘已经滑出，它不会弹出。

import android.app.Service;
import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.EditText;

public class BringOutTheSoftInputOnFocusEditTextView extends EditText {

    protected InputMethodManager inputMethodManager;

    public BringOutTheSoftInputOnFocusEditTextView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    public BringOutTheSoftInputOnFocusEditTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public BringOutTheSoftInputOnFocusEditTextView(Context context) {
        super(context);
        init();
    }

    private void init() {
        this.inputMethodManager = (InputMethodManager)getContext().getSystemService(Service.INPUT_METHOD_SERVICE);
        this.setOnFocusChangeListener(new View.OnFocusChangeListener() {
            @Override
            public void onFocusChange(View v, boolean hasFocus) {
                if (hasFocus) {
                    BringOutTheSoftInputOnFocusEditTextView.this.inputMethodManager.showSoftInput(BringOutTheSoftInputOnFocusEditTextView.this, InputMethodManager.SHOW_FORCED);
                }
            }
        });
    }

    @Override
    protected void onVisibilityChanged(View changedView, int visibility) {
        super.onVisibilityChanged(changedView, visibility);
        if (visibility == View.VISIBLE) {
            BringOutTheSoftInputOnFocusEditTextView.this.requestFocus();
        }
    }

}

看看https://stackoverflow.com/a/39144104/2914140，我简化了一点:

// In onCreateView():
view.edit_text.run {
    requestFocus()
    post { showKeyboard(this) }
}

fun showKeyboard(view: View) {
    val imm = view.context.getSystemService(
        Context.INPUT_METHOD_SERVICE) as InputMethodManager?
    imm?.showSoftInput(view, InputMethodManager.SHOW_IMPLICIT)
}

它比https://stackoverflow.com/a/11155404/2914140:好

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

因为当你按Home键并移动到主屏幕时，键盘会保持打开状态。

<activity
    ...
    android:windowSoftInputMode="stateVisible" >
</activity>

or

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

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。