下面的代码将帮助您创建可以从任何地方调用的通用函数。

import android.app.Activity
import android.content.Context
import android.support.design.widget.Snackbar
import android.view.View
import android.view.inputmethod.InputMethodManager

public class KeyboardHider {
    companion object {

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

    }

}

使用一行代码从任何地方调用Above方法。

CustomSnackbar.hideKeyboard(view, this@ActivityName)

视图可以是任何内容，例如活动的根布局。

您可以使用InputMethodManager强制Android隐藏虚拟键盘，调用hideSoftInputFromWindow，传入包含焦点视图的窗口的标记。

// Check if no view has focus:
View view = this.getCurrentFocus();
if (view != null) {  
    InputMethodManager imm = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
    imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
}

这将在所有情况下强制隐藏键盘。在某些情况下，您需要将InputMethodManager.HIDE_IMPLICIT_ONLY作为第二个参数传递，以确保仅在用户未显式强制显示键盘时（通过按住菜单）隐藏键盘。

注意：如果您想在Kotlin中执行此操作，请使用：上下文getSystemService（Context.INPUT_METHOD_SERVICE）作为InputMethodManager

Kotlin语法

// Only runs if there is a view that is currently focused
this.currentFocus?.let { view ->
    val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager
    imm?.hideSoftInputFromWindow(view.windowToken, 0)
}

Kotlin版本

val imm: InputMethodManager = getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
//Hide:
imm.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY, 0);
//Show
imm.toggleSoftInput(InputMethodManager.SHOW_IMPLICIT, 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);
    }
}

简单编码：在onCreate（）中使用此代码

getWindow().setSoftInputMode(
    WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN
);

下面是如何在Mono for Android（AKA MonoDroid）中实现的

InputMethodManager imm = GetSystemService (Context.InputMethodService) as InputMethodManager;
if (imm != null)
    imm.HideSoftInputFromWindow (searchbox.WindowToken , 0);