[英]How to create buttons like keyboard keys in android?
这个问题似乎微不足道。 我想为我的应用创建一个像键盘键的按钮。 当我点击它时,一个弹出窗口出现在该按钮上方,显示按下的字母。 除了一件事以外,一切都很好。 当我将onFocusChangedListener添加到按钮时,没有任何反应。 我需要让我的按钮充当键盘键,但我不知道如何。
正如您在此处所看到的,当按钮聚焦时,会出现一个弹出窗口。 我想这样做,但onFocusChangeListener
不起作用。 我知道我可以使用KeyboardView
来实现这一点,但我不想使用它,因为一些其他问题,如居中按钮和设置键的高度与layout_weight。 所以我需要使用普通按钮。
我的第一次尝试:
button.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View v, boolean hasFocus) {
if (hasFocus) {
popupWindow.showAtLocation(keyboardPopup, Gravity.NO_GRAVITY, location.left - 10, location.top - button.getHeight());
} else {
popupWindow.dismiss();
}
}
});
结果:什么都没发生。 弹出窗口根本没有出现。
编辑:我添加了button.setFocusableInTouchMode(true);
正如阿什利建议的那样,onFocusChanged现在正在被召唤,但它的行为非常奇怪。 弹出窗口有时会显示,但在显示时,它永远不会消失......
我的第二次尝试:
button.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
popupWindow.showAtLocation(keyboardPopup, Gravity.NO_GRAVITY, location.left - 10, location.top - button.getHeight());
break;
case MotionEvent.ACTION_UP:
popupWindow.dismiss();
break;
}
return true;
}
});
结果:这个行为很奇怪。 有时弹出窗口显示,有时不显示,但是当显示时,按钮也不会改变其状态。 应该已经集中注意力,但按钮没有任何反应,它就像是处于正常状态一样(Button的背景不会随着我的drawable xml中声明的state_focused而改变)。 似乎onTouchListener会覆盖按钮的功能。
这是我布局的一部分:
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="3">
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1">
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="Q"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="W"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="E"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="R"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="T"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="Y"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="U"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="I"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="O"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="P"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1">
<View
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="0.5" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="A"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="S"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="D"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="F"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="G"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="H"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="J"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="K"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="L"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<View
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="0.5" />
</LinearLayout>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1">
<View
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1.5" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="Z"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="X"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="C"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="V"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="B"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="N"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<Button
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1"
android:text="M"
android:background="@drawable/keyboard_button"
android:textColor="#FFFFFF"
android:onClick="onKeyboardClick" />
<View
android:layout_width="0dp"
android:layout_height="fill_parent"
android:layout_weight="1.5" />
</LinearLayout>
</LinearLayout>
在代码中:
public void onKeyboardClick(View view) {
//The view pressed is a button.
final Button button = (Button) view;
//Create a PopupWindow.
LayoutInflater inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
final View keyboardPopup = inflater.inflate(R.layout.keyboard_popup, null);
final PopupWindow popupWindow = new PopupWindow(keyboardPopup, view.getWidth() + 20, view.getHeight());
TextView keyboardKey = (TextView) keyboardPopup.findViewById(R.id.keyboard_key);
keyboardKey.setText(button.getText().toString());
//Get button location to show the popup above it.
int[] keyLocation = new int[2];
button.getLocationOnScreen(keyLocation);
final Rect location = new Rect();
location.left = keyLocation[0];
location.top = keyLocation[1];
location.right = location.left + button.getWidth();
location.bottom = location.top + button.getHeight();
//This is a temporary solution. I don't want to use that.
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//Show popup.
popupWindow.showAtLocation(keyboardPopup, Gravity.NO_GRAVITY, location.left - 10, location.top - button.getHeight());
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
//Dismiss popup.
popupWindow.dismiss();
}
}, 200);
}
});
}
任何帮助将不胜感激。 谢谢。
我建议你使用第二次尝试onTouchListener
! 你有2个问题:
1.按钮不会改变状态
实际上,当您覆盖onTouchListener
您必须自己模拟状态。 请看看这个SO线程是如何完成的: Android上的“按住”按钮需要使用onTouchListener更改状态(自定义XML选择器)
2.有时显示,有时不显示
这不应该发生,特别是如果您正确处理所有相关的触摸事件案例。 当用户触摸按钮时,您将希望显示弹出窗口,并在用户移出按钮时隐藏弹出窗口(通过向外滑动或将手指从屏幕上移开)。
请尝试以下代码示例:
button.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
v.setPressed(true);
showPopupWindow(...);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_OUTSIDE:
case MotionEvent.ACTION_CANCEL:
v.setPressed(false);
hidePopupWindow(...);
break;
}
return true;
}
});
getAction
来更好地处理多点触摸。 v.setPressed(...);
- 这将更新按钮状态。 我没有在你的代码中注意到它,但可能你遗漏了。
btn.setFocusableInTouchMode(true);
btn.setFocusable(true);
对于焦点改变监听器。
holder.sAttedenceList.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id)
{
if (!parent.hasFocus()) {
return;
}
不是完整的代码,而是这对我有用的一般结构。
而不是设置OnTouchListener
,尝试OnTouchListener
Button
并重写onTouchEvent
本身:
public class KeyboardButton extends Button
{
@Override
public boolean onTouchEvent(MotionEvent event)
{
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
popupWindow.showAtLocation(keyboardPopup, Gravity.NO_GRAVITY, location.left - 10, location.top - button.getHeight());
break;
case MotionEvent.ACTION_UP:
popupWindow.dismiss();
break;
}
return super.onTouchEvent(event);
}
}
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