我可以从两个不同的活动，A和B.活动C有一键到达活动℃。我想检查，如果我去到C从A或C来自B.如果我从A到C，我想按钮做一件事，如果我选自B到C，我想按钮做另一件事。

是否有可能以检查其中previous活动是？

这样的事情...

 否则，如果（ID == R.id.action_button）{

如果（previosActivity == A）{

    意向意图=新的意图（这一点，NewActivity.class）;
    startActivity（意向）;
}

否则，如果（previosActivity == b）{

    意向意图=新的意图（这一点，AnotherActivity.class）;
    startActivity（意向）;
}

返回true;
}
 

解决方案

当你去活动ç构成任何活动，您可以传递一个额外通过意图。然后你就可以检索额外在活动ç并根据需要使用它

例如：（未经测试code）

当你去从A到C

 意图mIntent =新的意图（这一点，ActivityC.class）; //'这'是活动一
extras.putExtra（FROM_ACTIVITY，A）;
startActivity（mIntent）;
 

当你去从B到C

 意图mIntent =新的意图（这一点，ActivityC.class）; //'这'是b活动
extras.putExtra（FROM_ACTIVITY，B）;
startActivity（mIntent）;
 

现在在活动ç，您retreive这样的：

 意图mIntent = getIntent（）;
字符串previousActivity = mIntent.getStringExtra（FROM_ACTIVITY）;
 

然后你可以用

如果（previousActivity.equals（A））{...} 或

如果（previousActivity.equals（B））{...}

在你的问题。

I can reach activity C from two different activities, A and B. Activity C has one button. I would like to check if I went to C from A or to C from B. If I went from A to C, I would like the button to do one thing and if I went from B to C, I would like the button to do another thing.

Is it possible to check which the previous activity was?

Something like this...

else if (id == R.id.action_button) {

if (previosActivity == A) {

    Intent intent = new Intent(this, NewActivity.class);
    startActivity(intent);  
}

else if (previosActivity == B) {

    Intent intent = new Intent(this, AnotherActivity.class);
    startActivity(intent);
}

return true;
}

When you go to Activity C form any of the activities, you can pass an extra through the intent. Then you can then retrieve that extra in Activity C and use it as desired

Eg. (Untested code)

When You go from A to C:

Intent mIntent = new Intent(this, ActivityC.class); //'this' is Activity A
extras.putExtra("FROM_ACTIVITY", "A"); 
startActivity(mIntent);

When You go from B to C:

Intent mIntent = new Intent(this, ActivityC.class); //'this' is Activity B
extras.putExtra("FROM_ACTIVITY", "B"); 
startActivity(mIntent);

Now in Activity C, you retreive this:

Intent mIntent = getIntent();
String previousActivity= mIntent.getStringExtra("FROM_ACTIVITY");

Then you can use

if (previousActivity.equals("A")){...} or

if (previousActivity.equals("B")){...}

as in your question.