您还可以创建EditText的自定义扩展，该扩展在接收到焦点时知道打开软键盘。这就是我最后要做的。以下是对我有效的方法:

public class WellBehavedEditText extends EditText {
    private InputMethodManager inputMethodManager;
    private boolean showKeyboard = false;

    public WellBehavedEditText(Context context) {
        super(context);
        this.initializeWellBehavedEditText(context);
    }

    public WellBehavedEditText(Context context, AttributeSet attributes) {
        super(context, attributes);
        this.initializeWellBehavedEditText(context);
    }

    public WellBehavedEditText(Context context, AttributeSet attributes, int defStyleAttr) {
        super(context, attributes, defStyleAttr);
        this.initializeWellBehavedEditText(context);
    }

    public WellBehavedEditText(Context context, AttributeSet attributes, int defStyleAttr, int defStyleRes) {
        super(context, attributes, defStyleAttr, defStyleRes);
        this.initializeWellBehavedEditText(context);
    }

    private void initializeWellBehavedEditText(Context context) {
        this.inputMethodManager = (InputMethodManager)context.getSystemService(Context.INPUT_METHOD_SERVICE);

        final WellBehavedEditText editText = this;
        this.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                if(showKeyboard) {
                    showKeyboard = !(inputMethodManager.showSoftInput(editText, InputMethodManager.SHOW_FORCED));
                }
            }
        });
    }

    @Override
    protected void onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect) {
        if(!focused) this.showKeyboard = false;
        super.onFocusChanged(focused, direction, previouslyFocusedRect);
    }

    @Override
    public boolean requestFocus(int direction, Rect previouslyFocusedRect) {
        boolean result = super.requestFocus(direction, previouslyFocusedRect);
        this.showKeyboard = true;
        final WellBehavedEditText self = this;
        this.post(new Runnable() {
            @Override
            public void run() {
                showKeyboard = !(inputMethodManager.showSoftInput(self, InputMethodManager.SHOW_FORCED));
            }
        });
        return result;
    }
}

showSoftInput根本不为我工作。

我想我需要设置输入模式:(这里在manifest中的Activity组件中)

android:windowSoftInputMode="stateVisible" 

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

我做了这个帮助课。 只需要传递context和你想要聚焦的View show keyboard和hide keyboard。 我希望这能有所帮助。

public class FocusKeyboardHelper {

private View view;
private Context context;
private InputMethodManager imm;

public FocusKeyboardHelper(Context context, View view){
    this.view = view;
    this.context = context;
    imm = (InputMethodManager) context.getSystemService(context.INPUT_METHOD_SERVICE);
}

public void focusAndShowKeyboard(){

    view.requestFocus();
    imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, InputMethodManager.HIDE_IMPLICIT_ONLY);

}

public void hideKeyBoard(){
    imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
}

}

 void requestFocus(View editText, Activity activity)
{
    try {
        editText.requestFocus();
        InputMethodManager imm = (InputMethodManager) a.getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.showSoftInput(editText, InputMethodManager.SHOW_IMPLICIT);
        activity.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE);
    } catch (Exception e) {
        e.printStackTrace();
    }

}

加上这一行也不要忘记

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

信不信由你，当我发现活动动画可以禁用软键盘时，我的软键盘问题得到了解决。当你用

i.setFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);

and

overridePendingTransition(0, 0);

它可以隐藏软键盘，没有办法显示它。