对于Xamarin.Android：

public void HideKeyboard()
{
    var imm = activity.GetSystemService(Context.InputMethodService).JavaCast<InputMethodManager>();
    var view = activity.CurrentFocus ?? new View(activity);
    imm.HideSoftInputFromWindow(view.WindowToken, HideSoftInputFlags.None);
}

这对我有用。

public static void hideKeyboard(Activity act, EditText et){
    Context c = act.getBaseContext();
    View v = et.findFocus();
    if(v == null)
        return;
    InputMethodManager inputManager = (InputMethodManager) c.getSystemService(Context.INPUT_METHOD_SERVICE);
    inputManager.hideSoftInputFromWindow(v.getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
}

Meier的解决方案也适用于我。在我的例子中，我的应用程序的顶层是一个选项卡宿主，我想在切换选项卡时隐藏关键字-我从选项卡宿主视图获取窗口令牌。

tabHost.setOnTabChangedListener(new OnTabChangeListener() {
    public void onTabChanged(String tabId) {
        InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.hideSoftInputFromWindow(tabHost.getApplicationWindowToken(), 0);
    }
}

下面是隐藏和显示方法。

科特林

fun hideKeyboard(activity: Activity) {
    val v = activity.currentFocus
    val imm = activity.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    assert(v != null)
    imm.hideSoftInputFromWindow(v!!.windowToken, InputMethodManager.HIDE_NOT_ALWAYS)
}

private fun showKeyboard(activity: Activity) {
    val v = activity.currentFocus
    val imm = activity.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    assert(v != null)
    imm.showSoftInput(v, InputMethodManager.SHOW_IMPLICIT)
}

Java

public static void hideKeyboard(Activity activity) {
    View v = activity.getCurrentFocus();
    InputMethodManager imm = (InputMethodManager) activity.getSystemService(Context.INPUT_METHOD_SERVICE);
    assert imm != null && v != null;
    imm.hideSoftInputFromWindow(v.getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
}

private static void showKeyboard(Activity activity) {
    View v = activity.getCurrentFocus();
    InputMethodManager imm = (InputMethodManager) activity.getSystemService(Context.INPUT_METHOD_SERVICE);
    assert imm != null && v != null;
    imm.showSoftInput(v, InputMethodManager.SHOW_IMPLICIT);
}

感谢上帝，它在11年后得到了官方支持

首先将依赖实现“androidx.core:core-ktx:1.7.0”添加到appgradle

然后从ViewCompat或WindowCompat类获取InsetsController。

最后使用InsetsController的hide（）和show（）函数

已编辑添加对Dialog的支持。在BottomSheetDialog中提供@隆德夫。使用更安全的方式获取活动，而不是直接从上下文中强制转换。

import android.app.Activity
import android.app.Dialog
import android.content.Context
import android.content.ContextWrapper
import android.view.View
import androidx.core.view.ViewCompat
import androidx.core.view.WindowCompat
import androidx.core.view.WindowInsetsCompat
import androidx.fragment.app.Fragment

fun View.showKeyboard() = ViewCompat.getWindowInsetsController(this)?.show(WindowInsetsCompat.Type.ime())
fun View.hideKeyboard() = ViewCompat.getWindowInsetsController(this)?.hide(WindowInsetsCompat.Type.ime())

fun Dialog.showKeyboard() = window?.decorView?.showKeyboard()
fun Dialog.hideKeyboard() = window?.decorView?.hideKeyboard()

fun Context.showKeyboard() = getActivity()?.showKeyboard()
fun Context.hideKeyboard() = getActivity()?.hideKeyboard()

fun Fragment.showKeyboard() = activity?.showKeyboard()
fun Fragment.hideKeyboard() = activity?.hideKeyboard()

fun Activity.showKeyboard() = WindowCompat.getInsetsController(window, window.decorView)?.show(WindowInsetsCompat.Type.ime())
fun Activity.hideKeyboard() = WindowCompat.getInsetsController(window, window.decorView)?.hide(WindowInsetsCompat.Type.ime())

fun Context.getActivity(): Activity? {
    return when (this) {
        is Activity -> this
        is ContextWrapper -> this.baseContext.getActivity()
        else -> null
    }
}

下面是旧的anwser

下面是github上的简单项目

import android.app.Activity
import android.app.Dialog
import android.content.Context
import android.content.ContextWrapper
import android.view.View
import androidx.core.view.ViewCompat
import androidx.core.view.WindowCompat
import androidx.core.view.WindowInsetsCompat
import androidx.fragment.app.Fragment

fun View.showKeyboard() = ViewCompat.getWindowInsetsController(this)?.show(WindowInsetsCompat.Type.ime())
fun View.hideKeyboard() = ViewCompat.getWindowInsetsController(this)?.hide(WindowInsetsCompat.Type.ime())

fun Dialog.showKeyboard() = window?.decorView?.showKeyboard()
fun Dialog.hideKeyboard() = window?.decorView?.hideKeyboard()

fun Context.showKeyboard() = getActivity()?.showKeyboard()
fun Context.hideKeyboard() = getActivity()?.hideKeyboard()

fun Fragment.showKeyboard() = activity?.showKeyboard()
fun Fragment.hideKeyboard() = activity?.hideKeyboard()

fun Activity.showKeyboard() = WindowCompat.getInsetsController(window, window.decorView)?.show(WindowInsetsCompat.Type.ime())
fun Activity.hideKeyboard() = WindowCompat.getInsetsController(window, window.decorView)?.hide(WindowInsetsCompat.Type.ime())

fun Context.getActivity(): Activity? {
    return when (this) {
        is Activity -> this
        is ContextWrapper -> this.baseContext.getActivity()
        else -> null
    }
}

从碎片移动到碎片时

fun hideKeyboard(activity: Activity?): Boolean {
    val inputManager = activity?.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager?
    if (inputManager != null) {
        val currentFocus = activity?.currentFocus
        if (currentFocus != null) {
            val windowToken = currentFocus.windowToken
            if (windowToken != null) {
                return inputManager.hideSoftInputFromWindow(windowToken, 0)
            }
        }
    }
    return false
}

fun showKeyboard(editText: EditText) {
    val imm = editText.context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    imm.hideSoftInputFromWindow(editText.windowToken, 0)
    imm.toggleSoftInput(InputMethodManager.SHOW_IMPLICIT, 0)
    editText.requestFocus()
}