java - 在 fragment 中链接两个按钮

Question

我在将两个按钮从 fragment 链接到类时遇到问题。我有一个正在工作，但任何将第二个链接到不同类的尝试都失败了。这是我的一个按钮的代码。提前致谢!

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    View view = inflater.inflate(R.layout.account, container, false);

    Button button = (Button)view.findViewById(R.id.btGlobex);
    button.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View v){
            switch(v.getId()){

                case R.id.btGlobex:
                    Intent intent = new Intent(getActivity(), GlobexActivity.class);
                    startActivity(intent);//Edited here
                    break;
            }
        }
    });

    return view;
}

更新:我收到了一些很好的回复，但是当我单击帐户 fragment 时，我的应用程序崩溃了，我不知道为什么。更新后的代码如下:

public class AccountFragment extends Fragment implements View.OnClickListener{

    public AccountFragment() {

    }

    public static AccountFragment newInstance() {
        AccountFragment fragment = new AccountFragment();
        return fragment;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.account, container, false);

        Button btGlobex = (Button)getView().findViewById(R.id.btGlobex);
        btGlobex.setOnClickListener(onClickListener);
        Button btUmbrella = (Button)getView().findViewById(R.id.btUmbrella);
        btUmbrella.setOnClickListener(onClickListener);
        return view;
    }

    private View.OnClickListener onClickListener = new View.OnClickListener() {
        @Override
        public void onClick(View v){
            switch(v.getId()){

                case R.id.btGlobex:
                    Intent intent1 = new Intent(getActivity(), GlobexActivity.class);
                    startActivity(intent1);//Edited here
                    break;
                case R.id.btUmbrella:
                    Intent intent2 = new Intent(getActivity(), UmbrellaActivity.class);
                    startActivity(intent2);//Edited here
                    break;
            }
        }
    };

    @Override
    public void onClick(View view) {

    }
}

我收到以下错误日志

03-08 20:10:40.974 5458-5458/com.qreceipts.qreceipts E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.qreceipts.qreceipts, PID: 5458
java.lang.NullPointerException
at com.qreceipts.qreceipts.AccountFragment.onCreateView(AccountFragment.java:29)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2189)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1299)
at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1528)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1595)
at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:757)
at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2355)
at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2146)
at android.support.v4.app.FragmentManagerImpl.optimizeAndExecuteOps(FragmentManager.java:2098)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2008)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:710)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5021)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:827)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:643)
at dalvik.system.NativeStart.main(Native Method)

再次感谢您的帮助!

Answer 1

我认为问题在于当你这样做时

Button button = (Button)view.findViewById(R.id.btGlobex);

此按钮始终会链接到 R.id.btGlobex，因此您的 v.getId() switch case 始终会获取 R.id.btGlobex 的 id

如果您希望第二个按钮使用不同的类启动 Intent ，则需要通过第二个按钮上的 findViewById 执行对第一个按钮所做的操作，并向其添加一个 onClickListener 来启动第二个类，或者实现我认为 onClickListener 接口(interface)是这样的:

public class YourFragment extends Fragment implements View.OnClickListener {

并对 onCreateView 中的按钮执行此操作:

Button button = (Button) view.findViewById(R.id.button1);
button.setOnClickListener(this);

Button button2 = (Button) view.findViewById(R.id.button2);
button2.setOnClickListener(this);

然后将你的 switch case 放在 onCreateView 之外作为它自己的方法:

@Override
public void onClick(View v) {
    // Switch cases here
}

参见this answer了解更多信息。

<小时/>

也许你应该像这样设置你的 onClickListener ？

public class YourFragment extends Fragment implements View.OnClickListener {
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.account, container, false);

        Button btGlobex = (Button) view.findViewById(R.id.btGlobex);
        btGlobex.setOnClickListener(this);

        Button btUmbrella = (Button) view.findViewById(R.id.btUmbrella);
        btUmbrella.setOnClickListener(this);

        return view;
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btGlobex:
                Intent intent1 = new Intent(getActivity(), GlobexActivity.class);
                startActivity(intent1);
                break;
            case R.id.btUmbrella:
                Intent intent2 = new Intent(getActivity(), UmbrellaActivity.class);
                startActivity(intent2);
                break;
            default:
                break;
        }
    }