使用Xamarin，这对我来说是一个片段:

using Android.Views.InputMethods;
using Android.Content;

...

if ( _txtSearch.RequestFocus() ) {
  var inputManager = (InputMethodManager) Activity.GetSystemService( Context.InputMethodService );
  inputManager.ShowSoftInput( _txtSearch, ShowFlags.Implicit );
}

当其他方法都不起作用时，就强制显示它:

editText.requestFocus();
InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
imm.toggleSoftInput(InputMethodManager.SHOW_FORCED, InputMethodManager.HIDE_IMPLICIT_ONLY);

然后，如果你想关闭它，例如在onPause()中，你可以调用:

InputMethodManager imm = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(editText.getWindowToken(), 0);

android:windowSoftInputMode="stateAlwaysVisible" - manifest文件中的>。

edittext.requestFocus ();-代码为>。

这将打开软键盘上的编辑文本有请求焦点作为活动出现。

在Activity的onResume()部分，你可以调用方法bringKeyboard();

 onResume() {
     EditText yourEditText= (EditText) findViewById(R.id.yourEditText);
     bringKeyboard(yourEditText);
 }


  protected boolean bringKeyboard(EditText view) {
    if (view == null) {
        return false;
    }
    try {
      // Depending if edittext has some pre-filled values you can decide whether to bring up soft keyboard or not
        String value = view.getText().toString();
        if (value == null) {
            InputMethodManager imm = (InputMethodManager)context.getSystemService(Context.INPUT_METHOD_SERVICE);
            imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
            return true;
        }
    } catch (Exception e) {
        Log.e(TAG, "decideFocus. Exception", e);
    }
    return false;
  }

只要在manifest文件中添加android:windowSoftInputMode="stateHidden"…

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;
    }
}