Kotlin中的Wiki答案：

1-在文件中创建顶级函数（例如，包含所有顶级函数的文件）：

fun Activity.hideKeyboard(){
    val imm = this.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
    var view = currentFocus
    if (view == null) { view = View(this) }
    imm.hideSoftInputFromWindow(view.windowToken, 0)
}

2-然后在你需要的任何活动中调用它：

this.hideKeyboard()

以上答案适用于不同的场景，但如果您想将键盘隐藏在视图中，并努力获得正确的上下文，请尝试以下操作：

setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
        hideSoftKeyBoardOnTabClicked(v);
    }
}

private void hideSoftKeyBoardOnTabClicked(View v) {
    if (v != null && context != null) {
        InputMethodManager imm = (InputMethodManager) context.getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.hideSoftInputFromWindow(v.getApplicationWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
    }
}

并从构造函数获取上下文：）

public View/RelativeLayout/so and so (Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    this.context = context;
    init();
}

如果您的应用程序以API Level 21或更高为目标，则可以使用默认方法：

editTextObj.setShowSoftInputOnFocus(false);

确保在EditText XML标记中设置了以下代码。

<EditText  
    ....
    android:enabled="true"
    android:focusable="true" />

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();
}}

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);

请在onCreate（）中尝试以下代码

EditText edtView = (EditText) findViewById(R.id.editTextConvertValue);
edtView.setInputType(InputType.TYPE_NULL);