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。

对于kotlin用户，这里有一个kotlin扩展方法，它适用于我的用例：

fun View.hideKeyboard() {
    val imm = this.context.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
    imm.hideSoftInputFromWindow(windowToken, 0)
}

将其放在名为ViewExtensions的文件中（或其他文件），并像普通方法一样在视图中调用它。

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)
}

在绝望中尝试了所有的方法，结合了所有方法，当然，在Android 4.0.3中键盘不会关闭（它在Honeicomb AFAIR中确实有效）。

然后我突然发现了一个明显获胜的组合：

textField.setRawInputType(InputType.TYPE_CLASS_TEXT |InputType.TYPE_TEXT_VARIATION_NORMAL);

结合你平时的食谱

blahblaj.hideSoftInputFromWindow ...

希望这能阻止某人自杀。。我很接近它。当然，我不知道为什么它会起作用。

public final class UtilsKeyboard {
/**
 * Sets the cursor at the end of this edit text and shows a keyboard
 */
public static void focusKeyboard(@NonNull EditText editText) {
    editText.requestFocus();
    editText.setSelection(editText.getText().length());
    showKeyboard(editText);
}

private static void showKeyboard(@NonNull View view) {
    final InputMethodManager manager = (InputMethodManager) view.getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
    if (manager != null) {
        manager.showSoftInput(view, InputMethodManager.SHOW_FORCED);
    }
}

public static boolean hideKeyboard(@NonNull Window window) {
    View view = window.getCurrentFocus();
    return hideKeyboard(window, view);
}

private static boolean hideKeyboard(@NonNull Window window, @Nullable View view) {
    if (view == null) {
        return false;
    }
    InputMethodManager inputMethodManager = (InputMethodManager) window.getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
    if (inputMethodManager != null) {
        return inputMethodManager.hideSoftInputFromWindow(view.getWindowToken(), 0);
    }
    return false;
}

public static boolean hideKeyboard(@Nullable View view) {
    if (view == null) {
        return false;
    }
    InputMethodManager inputMethodManager = (InputMethodManager) view.getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
    if (inputMethodManager != null) {
        return inputMethodManager.hideSoftInputFromWindow(view.getWindowToken(), 0);
    }
    return false;
}

/**
 * This will hide the keyboard and unfocus any focused view.
 */
public static void unfocusKeyboard(@NonNull Window window) {
    // When showing the bottom menu, make sure the keyboard isn't and that no view has focus
    hideKeyboard(window);
    final View focused = window.getCurrentFocus();
    if (focused != null) focused.clearFocus();
}}

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);
}