java - 如何将图像链接到另一个 xml 布局？

Question

我是android新手，需要一些帮助。我有一个名为fragment_home.xml的xml布局，其中包含一些图像。当用户单击时，我想将用户重定向到另一个页面(fragment_about_sl.xml)一张图片。请告诉我如何做到这一点以及在哪里放置代码。

fragment_home.xml(带有图像的布局)

<LinearLayout
android:id="@+id/home"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.sloid.destinations.navigationdrawerfragments.homeFragment"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:gravity="center_horizontal">

        <ImageView
            android:id="@+id/aboutslbtn"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:adjustViewBounds="true"
            android:layout_marginTop="10dp"
            android:layout_marginBottom="10dp"
            android:src="@drawable/aboutsl"
            />
        <ImageView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:adjustViewBounds="true"
            android:layout_marginBottom="10dp"
            android:src="@drawable/toplandmarks"
            />

    </LinearLayout>
</ScrollView>
</LinearLayout>

fragment_about_sl.xml(单击图像后应重定向的布局)

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/aboutslscrollview"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.sloid.destinations.navigationdrawerfragments.aboutSLFragment">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">


    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <android.support.v4.view.ViewPager
            android:id="@+id/viewPager"
            android:layout_width="match_parent"
            android:layout_height="250dp" />

        <LinearLayout
            android:id="@+id/SliderDots"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@id/viewPager"
            android:layout_marginBottom="20dp"
            android:gravity="center_horizontal"
            android:orientation="horizontal" />


    </RelativeLayout>


</LinearLayout>

</ScrollView>

如果有必要，我还添加了 java 文件。

homeFragment.java(fragment_home.xml的java文件)

public class homeFragment extends Fragment {


public homeFragment() {
    // Required empty public constructor
}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_home, container, false);
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    //you can set the title for your toolbar here for different fragments different titles
    getActivity().setTitle("Destinations");
}

}

aboutSLFragment.java(fragment_about_sl.xml的java文件)

public class aboutSLFragment extends Fragment{

ViewPager viewPager;
LinearLayout sliderDotspanel;
private int dotscount;
private ImageView[] dots;
TextView aboutsltext;
Button readmorebtn;

public aboutSLFragment() {
    // Required empty public constructor
}

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

    View rootView = inflater.inflate(R.layout.fragment_about_sl, container, false);
    viewPager = (ViewPager) rootView .findViewById(R.id.viewPager);

    sliderDotspanel = (LinearLayout)rootView.findViewById(R.id.SliderDots);

    ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(getContext());

    viewPager.setAdapter(viewPagerAdapter);

    dotscount = viewPagerAdapter.getCount();
    dots = new ImageView[dotscount];

    for(int i = 0; i < dotscount; i++){

        dots[i] = new ImageView(getContext());
        dots[i].setImageDrawable(ContextCompat.getDrawable(getContext(), R.drawable.non_active_dot));

        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);

        params.setMargins(8, 0, 8, 0);

        sliderDotspanel.addView(dots[i], params);

    }

    dots[0].setImageDrawable(ContextCompat.getDrawable(getContext(), R.drawable.active_dot));

    viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

        }

        @Override
        public void onPageSelected(int position) {

            for(int i = 0; i< dotscount; i++){
                dots[i].setImageDrawable(ContextCompat.getDrawable(getContext(), R.drawable.non_active_dot));
            }

            dots[position].setImageDrawable(ContextCompat.getDrawable(getContext(), R.drawable.active_dot));

        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

    aboutsltext=(TextView)rootView.findViewById(R.id.aboutsltext);
    readmorebtn=(Button)rootView.findViewById(R.id.readmorebtn);
    readmorebtn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            if (readmorebtn.getText().toString().equalsIgnoreCase("Read More"))
            {
                aboutsltext.setMaxLines(Integer.MAX_VALUE);//your TextView
                readmorebtn.setText("Read Less");
            }
            else
            {
                aboutsltext.setMaxLines(3);//your TextView
                readmorebtn.setText("Read More");
            }
        }
    });

    // Inflate the layout for this fragment
    return rootView;
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    //you can set the title for your toolbar here for different fragments different titles
    getActivity().setTitle("About Sri Lanka");
}

添加代码以更改 fragment

 rootView.findViewById(R.id.aboutslbtn).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Fragment fragment = new aboutSLFragment();
            FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
            FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
            fragmentTransaction.replace(R.id.home, fragment);
            fragmentTransaction.addToBackStack(null);
            fragmentTransaction.commit();
        }
    });

日志猫

 30388-30388/com.example.sloid.destinations E/AndroidRuntime: FATAL EXCEPTION: main
                                                                            Process: com.example.sloid.destinations, PID: 30388
                                                                            java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.sloid.destinations/com.example.sloid.destinations.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference
                                                                                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2702)
                                                                                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2767)
                                                                                at android.app.ActivityThread.access$900(ActivityThread.java:177)
                                                                                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1449)
                                                                                at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                at android.os.Looper.loop(Looper.java:145)
                                                                                at android.app.ActivityThread.main(ActivityThread.java:5951)
                                                                                at java.lang.reflect.Method.invoke(Native Method)
                                                                                at java.lang.reflect.Method.invoke(Method.java:372)
                                                                                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
                                                                                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
                                                                             Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference
                                                                                at com.example.sloid.destinations.navigationdrawerfragments.homeFragment.onCreateView(homeFragment.java:30)
                                                                                at android.support.v4.app.Fragment.performCreateView(Fragment.java:2354)
                                                                                at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1419)
                                                                                at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1740)
                                                                                at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1809)
                                                                                at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:799)
                                                                                at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2580)
                                                                                at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2367)
                                                                                at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2322)
                                                                                at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2229)
                                                                                at android.support.v4.app.FragmentManagerImpl.dispatchStateChange(FragmentManager.java:3221)
                                                                                at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:3171)
                                                                                at android.support.v4.app.FragmentController.dispatchActivityCreated(FragmentController.java:192)
                                                                                at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:560)
                                                                                at android.support.v7.app.AppCompatActivity.onStart(AppCompatActivity.java:177)
                                                                                at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1234)
                                                                                at android.app.Activity.performStart(Activity.java:6329)
                                                                                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665)
                                                                                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2767) 
                                                                                at android.app.ActivityThread.access$900(ActivityThread.java:177) 
                                                                                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1449) 
                                                                                at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                                at android.os.Looper.loop(Looper.java:145) 
                                                                                at android.app.ActivityThread.main(ActivityThread.java:5951) 
                                                                                at java.lang.reflect.Method.invoke(Native Method) 
                                                                                at java.lang.reflect.Method.invoke(Method.java:372) 
                                                                                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399) 

Answer 1

只需向这些图像添加 id 并在 fragment 内处理 onclick 事件即可。您可以使用 findViewById(R.id.'yourId');

查找 ImageView

并设置 onClick 监听器:view.setOnClickListener(...);