在活动中调用片段方法？

时间：2015-12-14 10:08:20

标签： android android-fragments fragment

我试图从一个活动调用一个片段方法，但它会导致一个OutOfMemoryError。我正在学习本教程Link 

Error reporting crash
                                                                   java.lang.OutOfMemoryError: Failed to allocate a 6289456 byte allocation with 4315368 free bytes and 4MB until OOM
                                                                       at java.lang.AbstractStringBuilder.enlargeBuffer(AbstractStringBuilder.java:95)
                                                                       at java.lang.AbstractStringBuilder.append0(AbstractStringBuilder.java:125)
                                                                       at java.lang.StringBuffer.append(StringBuffer.java:278)
                                                                       at java.io.StringWriter.write(StringWriter.java:123)
                                                                       at com.android.internal.util.FastPrintWriter.flushLocked(FastPrintWriter.java:358)
                                                                       at com.android.internal.util.FastPrintWriter.appendLocked(FastPrintWriter.java:303)
                                                                       at com.android.internal.util.FastPrintWriter.write(FastPrintWriter.java:625)
                                                                       at com.android.internal.util.FastPrintWriter.append(FastPrintWriter.java:658)
                                                                       at java.io.PrintWriter.append(PrintWriter.java:691)
                                                                       at java.io.PrintWriter.append(PrintWriter.java:687)
                                                                       at java.io.Writer.append(Writer.java:198)
                                                                       at java.lang.Throwable.printStackTrace(Throwable.java:324)
                                                                       at java.lang.Throwable.printStackTrace(Throwable.java:300)
                                                                       at android.util.Log.getStackTraceString(Log.java:343)
                                                                       at com.android.internal.os.RuntimeInit.Clog_e(RuntimeInit.java:61)
                                                                       at com.android.internal.os.RuntimeInit.-wrap0(RuntimeInit.java)
                                                                       at com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException(RuntimeInit.java:86)
                                                                       at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:693)
                                                                       at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:690)

渲染片段xml中的问题： enter image description here

这是我的片段xml： [ current_forefast_fragment 

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:tools="http://schemas.android.com/tools"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@drawable/bg_gradient">

<fragment
    android:id="@+id/current_fragment"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:name="koemdzhiev.com.stormy.Current_forecast_fragment"/>

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/iconImageView"
    android:src="@mipmap/clear_night"
    android:adjustViewBounds="true"
    android:scaleType="fitXY"
    android:contentDescription="@string/weatherIconDesc"
    android:layout_above="@+id/locationLabel"
    android:layout_marginBottom="20dp"
    android:layout_centerHorizontal="true"/>
<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="requesting current location..."
    android:id="@+id/locationLabel"
    android:textColor="@android:color/white"
    android:textSize="22sp"
    android:layout_above="@+id/timeLabel"
    android:layout_centerHorizontal="true"
    android:layout_marginBottom="51dp"/>

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="--"
    android:id="@+id/temperatureLabel"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true"
    android:textColor="@android:color/white"
    android:textSize="125sp"/>

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/degreeImageView"
    android:layout_alignTop="@+id/temperatureLabel"
    android:layout_toRightOf="@+id/temperatureLabel"
    android:layout_toEndOf="@+id/temperatureLabel"
    android:src="@mipmap/degree"
    android:layout_marginTop="27dp"
    android:layout_marginLeft="10dp"/>

</RelativeLayout>

这是我的片段代码：

public class Current_forecast_fragment extends Fragment {
private MainActivity mActivity;
@InjectView(R.id.timeLabel)
TextView mTimeLabel;
@InjectView(R.id.temperatureLabel)
TextView mTemperatureLabel;
@InjectView(R.id.humidityValue)
TextView mHumidityValue;
@InjectView(R.id.precipValue)
TextView mPrecipValue;
@InjectView(R.id.summaryLabel)
TextView mSummaryLabel;
@InjectView(R.id.locationLabel)
TextView mLocationLabel;
@InjectView(R.id.windSpeedValue)
TextView mWindSpeedValue;
@InjectView(R.id.iconImageView)
ImageView mIconImageView;
@InjectView(R.id.refreshImageView)
ImageView mRefreshImaveView;
@InjectView(R.id.progressBar)
ProgressBar mProgressBar;
@InjectView(R.id.degreeImageView)
ImageView mDegreeImageView;

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    mActivity = ((MainActivity) getActivity());
}

@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.current_forefast_fragment, container, false);
    ButterKnife.inject(this, v);


    return v;
}


public void toggleRefresh() {
    if (mProgressBar.getVisibility() == View.INVISIBLE) {
        mProgressBar.setVisibility(View.VISIBLE);
        mRefreshImaveView.setVisibility(View.INVISIBLE);
    } else {
        mProgressBar.setVisibility(View.INVISIBLE);
        mRefreshImaveView.setVisibility(View.VISIBLE);
    }

    // updates the dysplay with the data in the CUrrentWeather locaal object

}

public void updateDisplay() {
    Current current = mActivity.mForecast.getCurrent();
    //setting the current weather details to the ui
    mTemperatureLabel.setText(current.getTemperature() + "");
    mTimeLabel.setText("At " + current.getFormattedTime() + " it will be");
    mHumidityValue.setText(current.getHumidity() + "%");
    mPrecipValue.setText(current.getPrecipChange() + "%");
    mSummaryLabel.setText(current.getSummery());
    mWindSpeedValue.setText(current.getWindSpeed() + "");
    mLocationLabel.setText(current.getTimeZone());
    mActivity.getLocationName();
    Drawable drawable = ContextCompat.getDrawable(mActivity, current.getIconId());
    mIconImageView.setImageDrawable(drawable);

}

}

这是主要活动中导致空指针异常的代码。当我尝试将片段转换为Current_forecast_fragment：

时会发生这种情况 
public class MainActivity extends AppCompatActivity {
ViewPager pager;
ViewPagerAdapter adapter;
SlidingTabLayout tabs;
CharSequence Titles[]={"Current","Hourly","Daily"};
int Numboftabs =3;
Current_forecast_fragment mCurrent_forecast_fragment;

public static final String TAG = MainActivity.class.getSimpleName();
public static final String LOCATION_KEY = "location_key";
public Forecast mForecast;
public static final String DAILY_FORECAST = "DAILY_FORECAST";
public static final String HOURLY_FORECAST = "HOURLY_FORECAST";
//default coordinates - Gotse Delchev, UK Lati:57.156866 ; Long:
private double latitude = 41.5667;
private double longitude = 23.7333;
private LocationManager locationManager;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //-----------MY CODE STARTS HERE-----------------

    mCurrent_forecast_fragment = (Current_forecast_fragment) getSupportFragmentManager().findFragmentById(R.id.current_fragment);
    //Log.d("MainActivity",mCurrent_forecast_fragment.getTag() + "Georgi");
    getLocation();

    // Creating The ViewPagerAdapter and Passing Fragment Manager, Titles fot the Tabs and Number Of Tabs.
    adapter =  new ViewPagerAdapter(getSupportFragmentManager(),Titles,Numboftabs);

    // Assigning ViewPager View and setting the adapter
    pager = (ViewPager) findViewById(R.id.pager);
    pager.setAdapter(adapter);

    // Assiging the Sliding Tab Layout View
    tabs = (SlidingTabLayout) findViewById(R.id.tabs);
    tabs.setDistributeEvenly(true); // To make the Tabs Fixed set this true, This makes the tabs Space Evenly in Available width

    // Setting Custom Color for the Scroll bar indicator of the Tab View
    tabs.setCustomTabColorizer(new SlidingTabLayout.TabColorizer() {
        @Override
        public int getIndicatorColor(int position) {
            return getResources().getColor(R.color.tabsScrollColor);
        }
    });

    // Setting the ViewPager For the SlidingTabsLayout
    tabs.setViewPager(pager);




}

有什么建议吗？

1 个答案:

答案 0 :(得分：1)

您已将片段布局放置在片段current_forefast_fragment.xml中。这导致了Current_forecast_fragment和OutOfMemoryError的循环影响。因此，请从current_forefast_fragment.xml

中删除此行 
<fragment
    android:id="@+id/current_fragment"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:name="koemdzhiev.com.stormy.Current_forecast_fragment"/>

为了获得片段引用，您需要修改您想要保留MainActivity的{​​{1}}和其他片段类。我假设您有两个片段Current_forecast_fragment和Tab1.java。在第一个中，我们需要使用适当的方法定义Current_forecast_fragment.java接口：

Callback

该工具在课程import android.app.Activity; import android.os.Bundle; import android.support.annotation.Nullable; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.Button; /** * Created by hp1 on 21-01-2015. */ public class Tab1 extends Fragment { private Callback callback; public interface Callback{ Current_forecast_fragment getCurrentForecastFragment(); } @Override public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { View v =inflater.inflate(R.layout.tab_1,container,false); Button btn1 = (Button) v.findViewById(R.id.btn1); btn1.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { callback.getCurrentForecastFragment(); } }); return v; } @Override public void onAttach(Activity activity) { super.onAttach(activity); callback = (Callback) activity; } } 中提及Callback之后：

MainActivity

现在，您可以通过调用接口方法public class MainActivity extends AppCompatActivity implements Tab1.Callback { ViewPager pager; ViewPagerAdapter adapter; SlidingTabLayout tabs; CharSequence Titles[] = {"Current", "Hourly", "Daily"}; int Numboftabs = 3; Current_forecast_fragment mCurrent_forecast_fragment; public static final String TAG = MainActivity.class.getSimpleName(); public static final String LOCATION_KEY = "location_key"; public static final String DAILY_FORECAST = "DAILY_FORECAST"; public static final String HOURLY_FORECAST = "HOURLY_FORECAST"; //default coordinates - Gotse Delchev, UK Lati:57.156866 ; Long: private double latitude = 41.5667; private double longitude = 23.7333; private LocationManager locationManager; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //-----------MY CODE STARTS HERE----------------- //mCurrent_forecast_fragment = (Current_forecast_fragment) getSupportFragmentManager().findFragmentById(R.id.current_fragment); //Log.d("MainActivity",mCurrent_forecast_fragment.getTag() + "Georgi"); //getLocation(); // Creating The ViewPagerAdapter and Passing Fragment Manager, Titles fot the Tabs and Number Of Tabs. adapter = new ViewPagerAdapter(getSupportFragmentManager(), Titles, Numboftabs); // Assigning ViewPager View and setting the adapter pager = (ViewPager) findViewById(R.id.pager); pager.setAdapter(adapter); // Assiging the Sliding Tab Layout View tabs = (SlidingTabLayout) findViewById(R.id.tabs); tabs.setDistributeEvenly(true); // To make the Tabs Fixed set this true, This makes the tabs Space Evenly in Available width // Setting Custom Color for the Scroll bar indicator of the Tab View tabs.setCustomTabColorizer(new SlidingTabLayout.TabColorizer() { @Override public int getIndicatorColor(int position) { return getResources().getColor(R.color.tabsScrollColor); } }); // Setting the ViewPager For the SlidingTabsLayout tabs.setViewPager(pager); } public Current_forecast_fragment getCurrentForecastFragment() { // second argument is position of Current_forecast_fragment in ViewPagerAdapter mCurrent_forecast_fragment = (Current_forecast_fragment) adapter.instantiateItem(pager, 1); return mCurrent_forecast_fragment; } } 从Current_forecast_fragment访问Tab1.java实例。

相关问题
最新问题