简单编码：在onCreate（）中使用此代码

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

科特林

class KeyboardUtils{
    
    companion object{
        fun hideKeyboard(activity: Activity) {
            val imm: InputMethodManager = activity.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
            var view: View? = activity.currentFocus
            if (view == null) {
                view = View(activity)
            }
            imm.hideSoftInputFromWindow(view.windowToken, 0)
        }
    }
}

那就在你需要的地方打电话

碎片

KeyboardUtils.hideKeyboard(requireActivity())

活动

 KeyboardUtils.hideKeyboard(this)

我的解决方案：

用活动构造它（视图是可选的），使用处理程序发布它（有一些延迟，例如100ms更好）。直接调用输入管理器有时不起作用。只有在工作时才能获得“活动”。我认为这很正常。

如果您可以在通话时获取根视图组或编辑视图，只需发送它即可获得更好的结果。

public class CloseSoftKeyboardRunnable implements Runnable
{
    Activity activity;
    View view;  // for dialog will occur context getcurrentfocus == null. send a rootview to find currentfocus.

    public CloseSoftKeyboardRunnable(Activity activity, View view)
    {
        this.activity = activity;
        this.view = view;
    }

    public CloseSoftKeyboardRunnable(Activity activity)
    {
        this.activity = activity;
    }
    @Override
    public void run() {
        if (!activity.isFinishing())
        {
            InputMethodManager imm = (InputMethodManager)activity.getSystemService(Context.INPUT_METHOD_SERVICE);

            if (view == null) {
                view = activity.getCurrentFocus();
            }
            else
            {
                try {
                    view = ((ViewGroup)view).getFocusedChild();
                }
                catch ( Exception e) {}
            }

            Window window =  activity.getWindow();
            
            if (window != null)
            {
                if (view == null) {
                    try {
                        view = window.getDecorView();
                        view = ((ViewGroup)view).getFocusedChild();
                    }
                    catch ( Exception e) {}
                }

                if (view == null) {
                    view = window.getDecorView();
                }

                if (view != null) {
                    if (view instanceof EditText)
                    {
                        EditText edittext = ((EditText) view);
                        edittext.setText(edittext.getText().toString()); // reset edit text bug on some keyboards bug
                        edittext.clearFocus();
                    }

                    imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
                }
                window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
            }
        }
    }
}

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);
}

如果你使用Kotlin开发你的应用程序，这真的很容易做到。

添加此扩展功能：

对于活动：

fun Activity.hideKeyboard() {
    val inputManager = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    val view = currentFocus
    if (view != null) {
        inputManager.hideSoftInputFromWindow(view.windowToken, InputMethodManager.HIDE_NOT_ALWAYS)
    }
}

对于片段：

fun Fragment.hideKeyboard() {
    activity?.let {
        val inputManager = it.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
        val view = it.currentFocus
        if (view != null) {
            inputManager.hideSoftInputFromWindow(view.windowToken, InputMethodManager.HIDE_NOT_ALWAYS)
        }
    }
}

现在，您可以简单地调用片段或活动：

 hideKeyboard()

与Android 10（API 29）一起工作

val activityView = activity?.window?.decorView?.rootView
activityView?.let {
    val imm = activity?.getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager
    imm?.hideSoftInputFromWindow(it.windowToken, 0)
}