作为这一全面解决方案的替代方案，如果您想从任何地方关闭软键盘，而没有对用于打开键盘的（EditText）字段的引用，但仍然希望在该字段被聚焦时进行此操作，则可以使用（从“活动”）：

if (getCurrentFocus() != null) {
    InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), 0);
}

只需在BaseActivity和BaseFragment中为整个应用程序创建通用方法

在onCreate（）中初始化inputMethodManager

inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);

使用此方法隐藏和显示键盘

public void hideKeyBoard(View view) {
     if (view != null) {
         inputMethodManager.hideSoftInputFromWindow(view.getWindowToken(), 0);
      }
 }

public void showKeyboard(View view, boolean isForceToShow) {
      if (isForceToShow)
         inputMethodManager.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0);
      else if (view != null)
           inputMethodManager.showSoftInput(view, 0);
}

 //In Activity
        View v = this.getCurrentFocus();
        if (v != null) {
            InputMethodManager im = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
            im.hideSoftInputFromWindow(view.getWindowToken(), 0);
        }


//In Fragment
        View v = getActivity().getCurrentFocus();
        if (v != null) {
            InputMethodManager im = (InputMethodManager)getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
            im.hideSoftInputFromWindow(view.getWindowToken(), 0);
        }
```

我使用Kotlin扩展来显示和隐藏键盘。

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

fun View.hideKeyboard() {
  val inputMethodManager = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
  inputMethodManager.hideSoftInputFromWindow(windowToken, 0)
}

通过将Generic方法添加到Utility或Helper类。通过调用自己，您可以隐藏和显示键盘

fun AppCompatActivity.hideKeyboard() {
            val view = this.currentFocus
            if (view != null) {
                val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
                imm.hideSoftInputFromWindow(view.windowToken, 0)
            }
           window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN)

        }


 fun AppCompatActivity.showKeyboard() {
            val view = this.currentFocus
            if (view != null) {
                val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
                imm.hideSoftInputFromWindow(view.windowToken, 0)
            }                     window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN)

        }

public void hideKeyboard() 
{
    if(getCurrentFocus()!=null) 
    {
        InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
        inputMethodManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), 0);
    }
}


public void showKeyboard(View mView) {
    InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
    mView.requestFocus();
    inputMethodManager.showSoftInput(mView, 0);
}