Firebase数据库中仅显示最后一个元素 [英] Only the last element is shown in Firebase database

问题描述

我在Firebase中有一个示例数据库，旨在显示一些事实.当前，我希望textview显示所有五个示例事实1,2,3,4,5 ..，但仅显示最后一个.我应该在哪里修改我的代码?

I have a sample database in Firebase that is meant to display some facts. Currently, I want the textview to display all the five sample facts 1,2,3,4,5..but it shows only the last one. Where should I modify on my code?

Java示例:

fact = database.getInstance().getReference().child("Facts");

        fact.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {

                for (DataSnapshot postSnapshot : dataSnapshot.getChildren()){

                    Fact factdata = postSnapshot.getValue(Fact.class);

                    factViewBox.setText(factdata.getFactDetail());


                }


            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

还有json:

"Facts":{
    "01":{
   "factDetail":"1" 
   }
,

"02":{
   "factDetail":"2" 
}
,
"03":{
   "factDetail":"3" 
}
,
"04":{
   "factDetail":"4" 
}
,
"05":{
   "factDetail":"5" 
}

}

推荐答案

您的代码所做的只是将TextView中的当前文本替换为factdata.getFactDetail().

What your code doing is just replacing the current text in the TextView with the factdata.getFactDetail().

例如，您有3个元素1、2和3.然后您想要在TextView中显示该元素.使用您的代码，这就是发生的情况

For example you have 3 elements 1, 2, and 3. Then you want to display the element inside the TextView. With your code, this is what happen

第一次迭代:

element = elements[0];        // element = 1
factViewBox.setText(element); // TextView text is "1"

第二次迭代:

element = elements[1];        // element = 2
factViewBox.setText(element); // TextView text is "2"

第三次迭代:

element = elements[2];        // element = 3
factViewBox.setText(element); // TextView text is "3"

因此，您的TextView仅显示最后一个元素/事实详细信息

Therefore, your TextView only displaying the last element/fact detail

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