吐司在主要活动中效果很好，但在课堂上却不行

Question

Using Toast in the MainActivity works fine

Toast.makeText(getApplicationContext(), "Button is clicked", Toast.LENGTH_LONG).show();

but when I use it in a class, getApplicationContext() , gets red lined and it does not work. How can I make it work in a class?

Answer 1

You need to pass the context from Activity to the non Activity class and use the same there

  new NonActivityClass(ActivityName.this);

Then

 COntext mContext;
 public NonActivityClass(Context context)
 {
     mContext =context;
 }

Then

 Toast.makeText(mContext, "Button is clicked", Toast.LENGTH_LONG).show();

Note : Do not keep long-lived references to a context-activity (a reference to an activity should have the same life cycle as the activity itself) to avoid memory leaks.

Answer 2

如果您想从课堂上敬酒，则应将上下文发送给您的课堂。

Answer 3

It`s matter of context value not to worry.

Instead of using getApplicationContext() use Activityname.this