我已经为我的复选框
实现了setOnCheckedChangeListener
。
有没有办法可以调用?
checkbox.setChecked(false);
在不触发onCheckedChanged
的情况下
我已经为我的复选框
实现了setOnCheckedChangeListener
。
有没有办法可以调用?
checkbox.setChecked(false);
在不触发onCheckedChanged
的情况下
不,你不能这样做。 onCheckedChanged
方法直接从 setChecked
调用。 但你可以做以下操作:
mCheck.setOnCheckedChangeListener (null);
mCheck.setChecked (false);
mCheck.setOnCheckedChangeListener (mListener);
查看CheckBox的源代码和setChecked
的实现:
public void setChecked(boolean checked) {
if (mChecked != checked) {
mChecked = checked;
refreshDrawableState();
// Avoid infinite recursions if setChecked() is called from a listener
if (mBroadcasting) {
return;
}
mBroadcasting = true;
if (mOnCheckedChangeListener != null) {
mOnCheckedChangeListener.onCheckedChanged(this, mChecked);
}
if (mOnCheckedChangeWidgetListener != null) {
mOnCheckedChangeWidgetListener.onCheckedChanged(this, mChecked);
}
mBroadcasting = false;
}
}
mListener
?Checkbox
没有其 OnCheckChangeListener
的 getter 方法。 - tir38mListener
是 OnCheckChangedListener
接口的一个实现,是由程序员创建的。我的回答意味着程序员保持了对他们自己实现的引用 - mListener
。请注意不改变原来的意思。 - Shadeif(!compoundButton.isPressed()) {
return;
}
这将帮助我们确定复选框状态是通过编程方式还是用户操作改变的。
另一种可能的实现方式是使用自定义 CheckBox,这将让您选择是否要调用侦听器:
public class CheckBox extends AppCompatCheckBox {
private OnCheckedChangeListener mListener;
public CheckBox(final Context context) {
super(context);
}
public CheckBox(final Context context, final AttributeSet attrs) {
super(context, attrs);
}
public CheckBox(final Context context, final AttributeSet attrs, final int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
public void setOnCheckedChangeListener(final OnCheckedChangeListener listener) {
mListener = listener;
super.setOnCheckedChangeListener(listener);
}
public void setChecked(final boolean checked, final boolean alsoNotify) {
if (!alsoNotify) {
super.setOnCheckedChangeListener(null);
super.setChecked(checked);
super.setOnCheckedChangeListener(mListener);
return;
}
super.setChecked(checked);
}
public void toggle(boolean alsoNotify) {
if (!alsoNotify) {
super.setOnCheckedChangeListener(null);
super.toggle();
super.setOnCheckedChangeListener(mListener);
return;
}
super.toggle();
}
}
如果您更喜欢Kotlin版本:
class CheckBox @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0) : AppCompatCheckBox(context, attrs, defStyleAttr) {
private var listener: CompoundButton.OnCheckedChangeListener? = null
override fun setOnCheckedChangeListener(listener: CompoundButton.OnCheckedChangeListener?) {
this.listener = listener
super.setOnCheckedChangeListener(listener)
}
fun setChecked(checked: Boolean, alsoNotify: Boolean) {
if (!alsoNotify) {
super.setOnCheckedChangeListener(null)
super.setChecked(checked)
super.setOnCheckedChangeListener(listener)
return
}
super.setChecked(checked)
}
fun toggle(alsoNotify: Boolean) {
if (!alsoNotify) {
super.setOnCheckedChangeListener(null)
super.toggle()
super.setOnCheckedChangeListener(listener)
return
}
super.toggle()
}
}
使用示例:
checkBox.setChecked(true,false);
现在也可以在我的代码库中找到:
对于任何偶然发现这篇文章的人,一个更简单的方法是在复选框上使用标签,然后在其侦听器中检查该标签(代码使用 Kotlin 编写):
checkBox.tag = false
checkBox.setOnCheckedChangeListener{ buttonView, isChecked ->
if(checkBox.tag != true) {
// Do some stuff
} else {
checkBox.tag = false
}
当访问时,只需将标记设置为true,然后在您想要忽略值更改时将isChecked设置为true:
checkBox.tag = true
checkBox.isChecked = true
你还可以使用另一种setTag方法,需要一个键来将标签映射到键上,以便提高可理解性。但如果所有内容都限定在单个类中,几个注释字符串就足以解释发生了什么。如果您使用setonclickListener,它将能够正常工作,这是一种非常简单的方法,谢谢 :)
setOnCheckedChangeListener
中检查 isPressed
。switch.setOnCheckedChangeListener { buttonView, isChecked ->
when {
buttonView.isPressed -> {
foo(isChecked)
}
}
使用Kotlin扩展与@Shade的答案:
fun CompoundButton.setCustomChecked(value: Boolean,listener: CompoundButton.OnCheckedChangeListener) {
setOnCheckedChangeListener(null)
isChecked = value
setOnCheckedChangeListener(listener)
}
public class SafeCheckBox extends AppCompatCheckBox implements CompoundButton.OnCheckedChangeListener {
private OnSafeCheckedListener onSafeCheckedListener;
private int mIgnoreListener = CALL_LISTENER;
public static final int IGNORE = 0;
public static final int CALL_LISTENER = 1;
@Retention(RetentionPolicy.SOURCE)
@IntDef({IGNORE, CALL_LISTENER})
public @interface ListenerMode {
}
public SafeCheckBox(Context context) {
super(context);
init(context);
}
public SafeCheckBox(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public SafeCheckBox(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context);
}
/**
* @param checkState change state of the checkbox to
* @param mIgnoreListener true to ignore the listener else listener will be notified
*/
public void setSafeCheck(boolean checkState, @ListenerMode int mIgnoreListener) {
if (isChecked() == checkState) return; //already in the same state no need to fire listener.
if (onSafeCheckedListener != null) { // this to avoid a bug if the user listens for the event after using this method and in that case he will miss first check
this.mIgnoreListener = mIgnoreListener;
} else {
this.mIgnoreListener = CALL_LISTENER;
}
setChecked(checkState);
}
private void init(Context context) {
setOnCheckedChangeListener(this);
}
public OnSafeCheckedListener getOnSafeCheckedListener() {
return onSafeCheckedListener;
}
public void setOnSafeCheckedListener(OnSafeCheckedListener onSafeCheckedListener) {
this.onSafeCheckedListener = onSafeCheckedListener;
}
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
if (onSafeCheckedListener != null)
onSafeCheckedListener.onAlwaysCalledListener(buttonView, isChecked);// this has to be called before onCheckedChange
if (onSafeCheckedListener != null && (mIgnoreListener == CALL_LISTENER)) {
onSafeCheckedListener.onCheckedChanged(buttonView, isChecked);
}
mIgnoreListener = CALL_LISTENER;
}
/**
* Listener that will be called when you want it to be called.
* On checked change listeners are called even when the setElementChecked is called from code. :(
*/
public interface OnSafeCheckedListener extends OnCheckedChangeListener {
void onAlwaysCalledListener(CompoundButton buttonView, boolean isChecked);
}
}
然后您可以调用:
setSafeCheck(true,ListenerMode.IGNORE); // OnCheckedChange监听器将不会被通知
我认为以下是最简单易懂的解释(希望能对您有所帮助)
public class ProgrammableSwitchCompat extends SwitchCompat {
public boolean isCheckedProgrammatically = false;
public ProgrammableSwitchCompat(final Context context) {
super(context);
}
public ProgrammableSwitchCompat(final Context context, final AttributeSet attrs) {
super(context, attrs);
}
public ProgrammableSwitchCompat(final Context context, final AttributeSet attrs, final int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
public void setChecked(boolean checked) {
isCheckedProgrammatically = false;
super.setChecked(checked);
}
public void setCheckedProgrammatically(boolean checked) {
isCheckedProgrammatically = true;
super.setChecked(checked);
}
}
使用它
@Override
public void onCheckedChanged(CompoundButton compoundButton, boolean on) {
if (((ProgrammableSwitchCompat) compoundButton).isCheckedProgrammatically) {
return;
}
//...
((ProgrammableSwitchCompat) compoundButton).setCheckedProgrammatically(true);
//...
((ProgrammableSwitchCompat) compoundButton).setCheckedProgrammatically(false);
//...
}
使用 setChecked(boolean)
函数将会触发操作
就是这样
KOTLIN
class MyCheckBox @JvmOverloads constructor(
context: Context,
attrs: AttributeSet? = null,
defStyleAttr: Int = R.attr.switchStyle
) : AppCompatCheckBox(context, attrs, defStyleAttr) {
var programmatically = false
override fun setChecked(checked: Boolean) {
programmatically = false
super.setChecked(checked)
}
fun setCheckedProgrammatically(checked: Boolean) {
programmatically = true
super.setChecked(checked)
}
}
你可以尝试在视图中使用标签,这样做如何?
mCheck.setTag("ignore");
mCheck.setChecked(true);
mCheck.setTag(null);
并且
switch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton compoundButton, boolean selected) {
//If switch has a tag, ignore below
if(compoundButton.getTag() != null)
return;
if (selected) {
// do something
} else {
// do something else
}
}
});