我在这里已经阅读过这类问题，但答案似乎没有起作用。
当用户点击按钮时，我会显示Toast。当用户不断点击按钮时，即使用户退出活动，烤面包也会一次又一次地显示。
吐司的长度很短。由于文本很长，因此无法更改Toast的长度。
这就是我现在所尝试的：
Toast toast;
toast=Toast.makeText(getApplicationContext(),"text",Toast.LENGTH_SHORT);
if(toast.getView().isShown()==false){
toast.show();
}
这不起作用。
我试过了：
if(toast.getView().isShown()==true){
toast.cancel();
}
onStop()中的。由于某种原因，取消方法永远不会有效。
如果我在显示应用程序之前放置.cancel()，那么将会有另一个空检查。但这样做之后也无效。我可以显示一个对话框而不是一个吐司，但这不是一个解决方案。
有没有办法检查是否正在显示吐司？
供参考
答案 0 :(得分：13)
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，我首先取消静态参考，然后再显示新参考（并将其保存在静态参考中）。
这是我制作的Boast包装器的完整代码 - 它模仿了Toast方法，足以让我使用它。默认情况下，Boast将取消前一个，因此您不会构建等待显示的Toasts队列。
这段代码可以在我的Github主旨中找到：
如果您只是想知道如何在退出应用时取消通知，那么您会在那里找到很多帮助。如果您有改进或建议，请随意分叉并取得联系。这是一个非常古老的答案，但代码在一些应用程序的生产中已经稳定了一段时间。
BTW - 在大多数用例中，这应该是Toast 的直接替代品。
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();
}
}
答案 1 :(得分：4)
而不是取消祝酒词。改变文字。例如
Toast t;
t = Toast.makeText(this, "hi", 3000);
t.show();
当您需要不同的吐司时，请使用
t.setText("bye");
t.show();
如果你想解雇吐司，只需致电t.cancel()
答案 2 :(得分：1)
您可以通过调用Toast对象上的cancel（）取消单个Toasts。 AFAIK，你无法取消所有出色的祝酒词。
答案 3 :(得分：0)
尝试保留最后一片吐司的时间戳，并且在超时期限过去之前不要允许任何新的祝词。
类似的东西：
private static final long TOAST_TIMEOUT_MS = 2000; // tweak this constant
private static long lastToastTime = 0;
public void onButtonClicked() {
long now = System.currentTimeMillis();
if (lastToastTime + TOAST_TIMEOUT_MS < now) {
Toast.makeText(...).show();
lastToastTime = now;
}
}
在用户退出应用程序后，我不会担心单个吐司会持续一秒钟 - 这是非常标准的行为。