在Kotlin试试这个

 private fun hideKeyboard(){
    val imm = activity!!.getSystemService(INPUT_METHOD_SERVICE) as InputMethodManager
    imm.hideSoftInputFromWindow(activity!!.currentFocus!!.windowToken, 0)
}

在Java中尝试

 private void hideKeyboard(){
  InputMethodManager imm =(InputMethodManager)getSystemService(INPUT_METHOD_SERVICE);
  imm.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), 0);
}

Kotlin版本：

fun showKeyboard(mEtSearch: EditText, context: Context) {
        mEtSearch.requestFocus()
        val imm: InputMethodManager =
            context.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
        imm.showSoftInput(mEtSearch, 0)
}

这对我所有奇怪的键盘行为都有效

private boolean isKeyboardVisible() {
    Rect r = new Rect();
    //r will be populated with the coordinates of your view that area still visible.
    mRootView.getWindowVisibleDisplayFrame(r);

    int heightDiff = mRootView.getRootView().getHeight() - (r.bottom - r.top);
    return heightDiff > 100; // if more than 100 pixels, its probably a keyboard...
}

protected void showKeyboard() {
    if (isKeyboardVisible())
        return;
    InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    if (getCurrentFocus() == null) {
        inputMethodManager.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0);
    } else {
        View view = getCurrentFocus();
        inputMethodManager.showSoftInput(view, InputMethodManager.SHOW_FORCED);
    }
}

protected void hideKeyboard() {
    if (!isKeyboardVisible())
        return;
    InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    View view = getCurrentFocus();
    if (view == null) {
        if (inputMethodManager.isAcceptingText())
            inputMethodManager.toggleSoftInput(InputMethodManager.HIDE_NOT_ALWAYS, 0);
    } else {
        if (view instanceof EditText)
            ((EditText) view).setText(((EditText) view).getText().toString()); // reset edit text bug on some keyboards bug
        inputMethodManager.hideSoftInputFromInputMethod(view.getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
    }
}

只需调用下面的方法，如果键盘显示，它将隐藏键盘。

public void hideKeyboard() {
    try {
        InputMethodManager inputmanager = (InputMethodManager)this.getSystemService(Context.INPUT_METHOD_SERVICE);
        if (inputmanager != null) {
            inputmanager.hideSoftInputFromWindow(this.getCurrentFocus().getWindowToken(), 0);
        }
    } catch (Exception var2) {
    }

}

有时你只需要按回车键来折叠键盘在“编辑文本”框中指定属性

 android:imeOptions="actionDone" 

这将将Enter按钮更改为Done按钮，该按钮将关闭键盘。

非常简单的方法

我在所有的项目中都这样做，并且像做梦一样工作。在声明layout.xml中，只需添加以下一行：

android:focusableInTouchMode="true"

完整代码示例：

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:focusableInTouchMode="true">

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <ListView
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

    </ListView>

</android.support.constraint.ConstraintLayout>