Java 如何在按钮单击时添加/删除片段？
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How to add/remove Fragment on Button click?
提问by Abhi9
At present I have got a "RELATIVE_LAYOUT" container which I am using for adding my fragment. I am using OnClickListener on a button to load the fragment XML layout into the RelativeLayout container.
目前我有一个“RELATIVE_LAYOUT”容器，我用它来添加我的片段。我在按钮上使用 OnClickListener 将片段 XML 布局加载到 RelativeLayout 容器中。
What I want to achieve is that when I press the button once, the fragment should load...and when I press it again the fragment should be removed. I've already tried using integer to identify if fragment is loaded, but failed. Any help Appreciated...
我想要实现的是，当我按下按钮一次时，片段应该加载......当我再次按下它时，片段应该被删除。我已经尝试使用整数来确定片段是否已加载，但失败了。任何帮助表示赞赏...
CODE:
代码：
public class MainActivity extends Activity {
Button B1,B2;
int boolb1=0, boolb2=0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
B1 = (Button)findViewById(R.id.btn1);
B2 = (Button)findViewById(R.id.btn2);
B1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
FragmentOne f1 = new FragmentOne();
if(boolb1==0)
{ft.add(R.id.frg1, f1);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
boolb1=1;}
else
{ft.remove(f1);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_CLOSE);
boolb1=0;}
//ft.addToBackStack("f1");
ft.commit();
}
});
B2.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
FragmentTwo f2 = new FragmentTwo();
if(boolb2==0) {
ft.add(R.id.frg2, f2);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
boolb2=1;
} else {
ft.remove(f2);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_CLOSE);
boolb2=0;
}
//ft.addToBackStack("f2");
ft.commit();
}
});
}
采纳答案by Philipp Jahoda
Your issue is that you create a newFragmenteverytime you click the Button. You need to get a reference to the currently addedFragmentand then remove that one.
你的问题是，你创建一个新的Fragment每次点击的Button。您需要获取对当前添加的引用Fragment，然后删除该引用。
Furthermore, you no longer need to use the flag.
When adding the Fragment, you can tagit. Upon removing the Fragment, you can use the tag used for adding the Fragmentto get a reference to the currently added Fragment.
此外，您不再需要使用该标志。添加 时Fragment，您可以标记它。删除 后Fragment，您可以使用用于添加 的标记Fragment来获取对当前添加的引用Fragment。
Here is an example of how you should do it:
以下是您应该如何操作的示例：
private Button B1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
B1 = (Button)findViewById(R.id.btn1);
B1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
FragmentOne f = (FragmentOne) fm.findFragmentByTag("tag");
if(f == null) { // not added
f = new FragmentOne();
ft.add(R.id.frg1, f, "tag");
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
} else { // already added
ft.remove(f);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_CLOSE);
}
ft.commit();
}
});
// and so on ...
}
