添加到Manifest文件中的活动android:windowSoftInputMode=“stateHidden”。例子：

<activity
            android:name=".ui.activity.MainActivity"
            android:label="@string/mainactivity"
            android:windowSoftInputMode="stateHidden"/>

只需在活动中使用此优化代码：

if (this.getCurrentFocus() != null) {
    InputMethodManager inputManager = (InputMethodManager) this.getSystemService(Context.INPUT_METHOD_SERVICE);
    inputManager.hideSoftInputFromWindow(this.getCurrentFocus().getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
}

there are two ways to do so...

method 1:in manifest file

define the line **android:windowSoftInputMode="adjustPan|stateAlwaysHidden"** of code in your manifest.xml file as below...

<activity
            android:name="packagename.youactivityname"
            android:screenOrientation="portrait"
            android:windowSoftInputMode="adjustPan|stateAlwaysHidden" />

Method 2 : in Activity or Java class

 if(getCurrentFocus()!=null) {
            InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE)`enter code here`;
            inputMethodManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), 0);
        }

它会work....@ASK

如果要使用Java代码隐藏键盘，请使用以下命令：

  InputMethodManager imm = (InputMethodManager)this.getSystemService(Context.INPUT_METHOD_SERVICE);
  imm.hideSoftInputFromWindow(fEmail.getWindowToken(), 0);

或者，如果您希望始终隐藏键盘，请在AndroidManifest中使用此选项：

 <activity
 android:name=".activities.MyActivity"
 android:configChanges="keyboardHidden"  />

通过创建一个扩展来隐藏Kotlin中的软键盘，您可以全局使用该扩展。为此，需要创建一个Singleton类。

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

在需要隐藏键盘的片段类的活动中，可以使用mainlayout id调用此函数，如下所示

//constraintEditLayout is my main view layout, if you are using other layout like relative or linear layouts you can call with that layout id
constraintEditLayout.hideKeyboard()

如果有人感兴趣的话，我已经为Kotlin写了一个小扩展，但没有太多测试：

fun Fragment.hideKeyboard(context: Context = App.instance) {
    val windowToken = view?.rootView?.windowToken
    windowToken?.let {
        val imm = context.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
        imm.hideSoftInputFromWindow(windowToken, 0)
    }
}

App.instance是存储在Application中的静态“this”Application对象

更新：在某些情况下，windowToken为空。我增加了使用反射来检测键盘是否关闭的额外关闭方式

/**
 * If no window token is found, keyboard is checked using reflection to know if keyboard visibility toggle is needed
 *
 * @param useReflection - whether to use reflection in case of no window token or not
 */
fun Fragment.hideKeyboard(context: Context = MainApp.instance, useReflection: Boolean = true) {
    val windowToken = view?.rootView?.windowToken
    val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    windowToken?.let {
        imm.hideSoftInputFromWindow(windowToken, 0)
    } ?: run {
        if (useReflection) {
            try {
                if (getKeyboardHeight(imm) > 0) {
                    imm.toggleSoftInput(0, InputMethodManager.HIDE_NOT_ALWAYS)
                }
            } catch (exception: Exception) {
                Timber.e(exception)
            }
        }
    }
}

fun getKeyboardHeight(imm: InputMethodManager): Int = InputMethodManager::class.java.getMethod("getInputMethodWindowVisibleHeight").invoke(imm) as Int