在我的应用程序中，我为我的活动构建了一个日历小部件，当我将它滚动到上个月或下个月时，我让它敬酒并显示它。
问题是，吐司需要时间来显示，当我滚动它的速度足够快时，例如，我滚动到“2012/05”和“2012/06”并且没有暂停滚动到“2012/07”，我必须等待“2012/05”、“2012/06”、“2012/07”的Toast将一一呈现。
似乎Android有一个看不见的队列来管理toast
我怎样才能清理它并且只显示最后一个吐司？我可以立即显示特定的 Toast 而无需等待吗？
我搜索了“android.widget.Toast.java”并找到了一个方法cancel()，但不幸的是它不起作用如下。
if (t != null) {
t.cancel();
}
t = Toast.makeText(this.mContext, mHelper.getYear() + "年"
+ (mHelper.getMonth() + 1) + "月", Toast.LENGTH_SHORT);
t.show();
你只需要像这样声明一个“Toast”变量：
Toast toastMessage;
然后在你的函数中，这样做：
if (toastMessage!= null) {
toastMessage.cancel();
}
toastMessage= Toast.makeText(context, "The message you want to display", duration);
toastMessage.show();
这是我从另一个类似问题中复制的答案：
该Boast课程完全满足您的需求。最新的代码可以在 GitHub 上找到：
诀窍是跟踪显示的最后一个Toast，并取消那个。
我所做的是创建一个Toast包装器，其中包含对显示的最后一个 Toast 的静态引用。
当我需要显示一个新的时，我首先取消静态引用，然后再显示新的（并将其保存在静态中）。
这是我制作的包装器的完整代码Boast——它模仿了足够多的 Toast 方法供我使用。默认情况下，Boast将取消前一个，因此您不会建立等待显示的 Toast 队列。
如果您只想知道如何在退出应用程序时取消通知，您会在其中找到很多帮助。
package mobi.glowworm.lib.ui.widget;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.Resources;
import android.support.annotation.Nullable;
import android.widget.Toast;
import java.lang.ref.WeakReference;
/**
* {@link Toast} decorator allowing for easy cancellation of notifications. Use this class if you
* want subsequent Toast notifications to overwrite current ones. </p>
* <p/>
* By default, a current {@link Boast} notification will be cancelled by a subsequent notification.
* This default behaviour can be changed by calling certain methods like {@link #show(boolean)}.
*/
public class Boast {
/**
* Keeps track of certain Boast notifications that may need to be cancelled. This functionality
* is only offered by some of the methods in this class.
* <p>
* Uses a {@link WeakReference} to avoid leaking the activity context used to show the original {@link Toast}.
*/
@Nullable
private volatile static WeakReference<Boast> weakBoast = null;
@Nullable
private static Boast getGlobalBoast() {
if (weakBoast == null) {
return null;
}
return weakBoast.get();
}
private static void setGlobalBoast(@Nullable Boast globalBoast) {
Boast.weakBoast = new WeakReference<>(globalBoast);
}
// ////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Internal reference to the {@link Toast} object that will be displayed.
*/
private Toast internalToast;
// ////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Private constructor creates a new {@link Boast} from a given {@link Toast}.
*
* @throws NullPointerException if the parameter is <code>null</code>.
*/
private Boast(Toast toast) {
// null check
if (toast == null) {
throw new NullPointerException("Boast.Boast(Toast) requires a non-null parameter.");
}
internalToast = toast;
}
// ////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Make a standard {@link Boast} that just contains a text view.
*
* @param context The context to use. Usually your {@link android.app.Application} or
* {@link android.app.Activity} object.
* @param text The text to show. Can be formatted text.
* @param duration How long to display the message. Either {@link Toast#LENGTH_SHORT} or
* {@link Toast#LENGTH_LONG}
*/
@SuppressLint("ShowToast")
public static Boast makeText(Context context, CharSequence text, int duration) {
return new Boast(Toast.makeText(context, text, duration));
}
/**
* Make a standard {@link Boast} that just contains a text view with the text from a resource.
*
* @param context The context to use. Usually your {@link android.app.Application} or
* {@link android.app.Activity} object.
* @param resId The resource id of the string resource to use. Can be formatted text.
* @param duration How long to display the message. Either {@link Toast#LENGTH_SHORT} or
* {@link Toast#LENGTH_LONG}
* @throws Resources.NotFoundException if the resource can't be found.
*/
@SuppressLint("ShowToast")
public static Boast makeText(Context context, int resId, int duration)
throws Resources.NotFoundException {
return new Boast(Toast.makeText(context, resId, duration));
}
/**
* Make a standard {@link Boast} that just contains a text view. Duration defaults to
* {@link Toast#LENGTH_SHORT}.
*
* @param context The context to use. Usually your {@link android.app.Application} or
* {@link android.app.Activity} object.
* @param text The text to show. Can be formatted text.
*/
@SuppressLint("ShowToast")
public static Boast makeText(Context context, CharSequence text) {
return new Boast(Toast.makeText(context, text, Toast.LENGTH_SHORT));
}
/**
* Make a standard {@link Boast} that just contains a text view with the text from a resource.
* Duration defaults to {@link Toast#LENGTH_SHORT}.
*
* @param context The context to use. Usually your {@link android.app.Application} or
* {@link android.app.Activity} object.
* @param resId The resource id of the string resource to use. Can be formatted text.
* @throws Resources.NotFoundException if the resource can't be found.
*/
@SuppressLint("ShowToast")
public static Boast makeText(Context context, int resId) throws Resources.NotFoundException {
return new Boast(Toast.makeText(context, resId, Toast.LENGTH_SHORT));
}
// ////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Show a standard {@link Boast} that just contains a text view.
*
* @param context The context to use. Usually your {@link android.app.Application} or
* {@link android.app.Activity} object.
* @param text The text to show. Can be formatted text.
* @param duration How long to display the message. Either {@link Toast#LENGTH_SHORT} or
* {@link Toast#LENGTH_LONG}
*/
public static void showText(Context context, CharSequence text, int duration) {
Boast.makeText(context, text, duration).show();
}
/**
* Show a standard {@link Boast} that just contains a text view with the text from a resource.
*
* @param context The context to use. Usually your {@link android.app.Application} or
* {@link android.app.Activity} object.
* @param resId The resource id of the string resource to use. Can be formatted text.
* @param duration How long to display the message. Either {@link Toast#LENGTH_SHORT} or
* {@link Toast#LENGTH_LONG}
* @throws Resources.NotFoundException if the resource can't be found.
*/
public static void showText(Context context, int resId, int duration)
throws Resources.NotFoundException {
Boast.makeText(context, resId, duration).show();
}
/**
* Show a standard {@link Boast} that just contains a text view. Duration defaults to
* {@link Toast#LENGTH_SHORT}.
*
* @param context The context to use. Usually your {@link android.app.Application} or
* {@link android.app.Activity} object.
* @param text The text to show. Can be formatted text.
*/
public static void showText(Context context, CharSequence text) {
Boast.makeText(context, text, Toast.LENGTH_SHORT).show();
}
/**
* Show a standard {@link Boast} that just contains a text view with the text from a resource.
* Duration defaults to {@link Toast#LENGTH_SHORT}.
*
* @param context The context to use. Usually your {@link android.app.Application} or
* {@link android.app.Activity} object.
* @param resId The resource id of the string resource to use. Can be formatted text.
* @throws Resources.NotFoundException if the resource can't be found.
*/
public static void showText(Context context, int resId) throws Resources.NotFoundException {
Boast.makeText(context, resId, Toast.LENGTH_SHORT).show();
}
// ////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Close the view if it's showing, or don't show it if it isn't showing yet. You do not normally
* have to call this. Normally view will disappear on its own after the appropriate duration.
*/
public void cancel() {
internalToast.cancel();
}
/**
* Show the view for the specified duration. By default, this method cancels any current
* notification to immediately display the new one. For conventional {@link Toast#show()}
* queueing behaviour, use method {@link #show(boolean)}.
*
* @see #show(boolean)
*/
public void show() {
show(true);
}
/**
* Show the view for the specified duration. This method can be used to cancel the current
* notification, or to queue up notifications.
*
* @param cancelCurrent <code>true</code> to cancel any current notification and replace it with this new
* one
* @see #show()
*/
public void show(boolean cancelCurrent) {
// cancel current
if (cancelCurrent) {
final Boast cachedGlobalBoast = getGlobalBoast();
if ((cachedGlobalBoast != null)) {
cachedGlobalBoast.cancel();
}
}
// save an instance of this current notification
setGlobalBoast(this);
internalToast.show();
}
}
您需要在正确的对象上调用方法。
toastObject.cancel()
这是代码。
final Toast toastobject = Toast.makeText(context, "This message will disappear when toast.close(); is called", Toast.LENGTH_SHORT);
现在可以使用 toastobject 的 Object。其参考
toastobject.cancel();
您可以在 Thread 中使用它，或者在您想关闭 Toast 时使用它。
您可以重复使用吐司，这将使其立即显示。
myToast.setText(toastMsg);
myToast.show();
当我们想显示另一个 Toast 时，有很多方法可以取消之前的 Toast。下面我写了一个最简单的方法来实现它。首先，我们必须创建一个可以在整个类中访问的变量。
private Toast toast;
在创建了整个类都可以访问的变量之后，我们必须在我们的类中创建一个方法来显示 toast 消息并检查之前的 toast 是否正在显示然后取消它。
public void showToast(String message) {
if (toast != null) {
toast.cancel();
}
toast = Toast.makeText(getApplicationContext(), message, Toast.LENGTH_SHORT);
toast.show();
}
您可以通过运行时调用上述方法来更改 toast 消息。
showToast("message 1");
//一段时间后
showToast("message 2");
希望能帮助到你。
Toast 有一个隐藏当前 toast 消息的方法
public void cancel() {
mTN.hide();
}
必要时尝试调用 t.cancel()。
您可以创建静态方法并使用它来显示敬酒：
public static Toast toast = null;
public static showToast(Context context,String msg){
if(toast!=null) //this will cancel the toast on the screen if one exists
toast.cancel();
toast = Toast.makeText(context,msg);
toast.show();
}
简单的。一旦你想创建另一个 toast，只需在 toast 上调用方法 .cancel() 即可。
首先像这样在类的顶部定义一个 Toast 变量
private Toast mToast;
稍后，当您想创建一个新的 Toast（并让旧的 Toast 消失）时，请执行此操作。
if(mToast != null) {
mToast.cancel(); //if a toast exists it deletes it, allowing you to create a new one
}
mToast = Toast.makeText(this, "This will show up now!", Toast.LENGTH_LONG);
mToast.show(); //creates the new toast.
public static Toast sToast=null;
// create Toast object;
public void showToast(String msg)
{
//here is checking whether toast object is null or not;if not null gonna cancel the toast that is showing in phone window and make it null;
if(sToast!=null)
{
sToast.cancel;
sToast=null;
}
//if toast object is null,gonna create new instance and make it shown on phone window.
if(sToast==null)
{
sToast=Toast.makeText(currentActivity.this,msg,Duration);
sToast.setGravity();
sToast.show();
}
}
迟来的：您的代码不起作用的原因是它Toast.makeText()没有返回Toast对它正在创建的引用。它只是一个帮助方法，旨在允许Toast快速轻松地创建，但不允许引用或取消。要取消，您必须执行以下操作：
t=Toast(requireContext())
t.setText(YOUR TEXT)
t.setDuration(1000)
t.show()
这样 t 将在调用构造函数时被分配一个引用，这将允许稍后取消。
您可以使用一种拍摄技术。好的，让我们开始定义：
private Toast mToast;
private showOnce=false;
稍后当你想展示一次吐司时：
if(showOnce==false){
mToast=Toast.makeText(this, "Once!", Toast.LENGTH_LONG);
mToast.show();
showOnce=true;
}