TextView에서 사용자 정의 글꼴 투구 NullPointerException

Question

나는 현재 사용중인 간단한 환영 슬라이더 활동에 사용자 정의 글꼴을 구현하려고합니다. 그러나, 나는 그것을 이전에했던 것과 같은 방식으로 구현하려고 시도했지만 계속 NullPointerException을 얻는다. 모든 것이 초기화되어 문제가 무엇인지 알 수는 없습니다. 모든 도움을 주시면 감사하겠습니다. 나는 전체 클래스와 XML 파일

package com.example.introslider; 

import android.content.Context; 
import android.content.Intent; 
import android.graphics.Color; 
import android.graphics.Typeface; 
import android.os.Build; 
import android.os.Bundle; 
import android.support.v4.view.PagerAdapter; 
import android.support.v4.view.ViewPager; 
import android.support.v7.app.AppCompatActivity; 
import android.text.Html; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.view.Window; 
import android.view.WindowManager; 
import android.widget.Button; 
import android.widget.LinearLayout; 
import android.widget.TextView; 

public class WelcomeActivity extends AppCompatActivity { 
private ViewPager viewPager; 
private MyViewPagerAdapter myViewPagerAdapter; 
private LinearLayout dotsLayout; 
private TextView[] dots; 
private int[] layouts; 
private Button btnSkip, btnNext; 
private PrefManager prefManager; 



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

    // Checking for first time launch - before calling setContentView() 
    prefManager = new PrefManager(this); 
    if (!prefManager.isFirstTimeLaunch()) { 
     launchHomeScreen(); 
     finish(); 
    } 

    // Making notification bar transparent 
    if (Build.VERSION.SDK_INT >= 21) { 
     getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN); 
    } 

    setContentView(R.layout.activity_welcome); 


    TextView tv = (TextView)findViewById(R.id.title_1); 
    Typeface tf = Typeface.createFromAsset(getAssets(), "fonts/orbit.ttf"); 
    tv.setTypeface(tf); 

    viewPager = (ViewPager) findViewById(R.id.view_pager); 
    dotsLayout = (LinearLayout) findViewById(R.id.layoutDots); 
    btnSkip = (Button) findViewById(R.id.btn_skip); 
    btnNext = (Button) findViewById(R.id.btn_next); 


    // layouts of all welcome sliders 
    // add few more layouts if you want 
    layouts = new int[]{ 
      R.layout.welcome_slide1, 
      R.layout.welcome_slide2, 
      R.layout.welcome_slide3, 
      R.layout.welcome_slide4}; 

    // adding bottom dots 
    addBottomDots(0); 

    // making notification bar transparent 
    changeStatusBarColor(); 

    myViewPagerAdapter = new MyViewPagerAdapter(); 
    viewPager.setAdapter(myViewPagerAdapter); 
    viewPager.addOnPageChangeListener(viewPagerPageChangeListener); 

    btnSkip.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      launchHomeScreen(); 
     } 
    }); 

    btnNext.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      // checking for last page 
      // if last page home screen will be launched 
      int current = getItem(+1); 
      if (current < layouts.length) { 
       // move to next screen 
       viewPager.setCurrentItem(current); 
      } else { 
       launchHomeScreen(); 
      } 
     } 
    }); 



} 

private void addBottomDots(int currentPage) { 
    dots = new TextView[layouts.length]; 

    int[] colorsActive = getResources().getIntArray(R.array.array_dot_active); 
    int[] colorsInactive = getResources().getIntArray(R.array.array_dot_inactive); 

    dotsLayout.removeAllViews(); 
    for (int i = 0; i < dots.length; i++) { 
     dots[i] = new TextView(this); 
     dots[i].setText(Html.fromHtml("&#8226;")); 
     dots[i].setTextSize(35); 
     dots[i].setTextColor(colorsInactive[currentPage]); 
     dotsLayout.addView(dots[i]); 
    } 

    if (dots.length > 0) 
     dots[currentPage].setTextColor(colorsActive[currentPage]); 
} 

private int getItem(int i) { 
    return viewPager.getCurrentItem() + i; 
} 

private void launchHomeScreen() { 
    prefManager.setFirstTimeLaunch(false); 
    startActivity(new Intent(WelcomeActivity.this, MainActivity.class)); 
    finish(); 
} 

// viewpager change listener 
ViewPager.OnPageChangeListener viewPagerPageChangeListener = new ViewPager.OnPageChangeListener() { 

    @Override 
    public void onPageSelected(int position) { 
     addBottomDots(position); 

     // changing the next button text 'NEXT'/'GOT IT' 
     if (position == layouts.length - 1) { 
      // last page. make button text to GOT IT 
      btnNext.setText(getString(R.string.start)); 
      btnSkip.setVisibility(View.GONE); 
     } else { 
      // still pages are left 
      btnNext.setText(getString(R.string.next)); 
      btnSkip.setVisibility(View.VISIBLE); 
     } 
    } 

    @Override 
    public void onPageScrolled(int arg0, float arg1, int arg2) { 

    } 

    @Override 
    public void onPageScrollStateChanged(int arg0) { 

    } 
}; 

/** 
* Making notification bar transparent 
*/ 
private void changeStatusBarColor() { 
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) { 
     Window window = getWindow(); 
     window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS); 
     window.setStatusBarColor(Color.TRANSPARENT); 
    } 
} 

/** 
* View pager adapter 
*/ 
public class MyViewPagerAdapter extends PagerAdapter { 
    private LayoutInflater layoutInflater; 

    public MyViewPagerAdapter() { 
    } 

    @Override 
    public Object instantiateItem(ViewGroup container, int position) { 
     layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE); 

     View view = layoutInflater.inflate(layouts[position], container, false); 
     container.addView(view); 

     return view; 
    } 

    @Override 
    public int getCount() { 
     return layouts.length; 
    } 

    @Override 
    public boolean isViewFromObject(View view, Object obj) { 
     return view == obj; 
    } 


    @Override 
    public void destroyItem(ViewGroup container, int position, Object object) { 
     View view = (View) object; 
     container.removeView(view); 
    } 
} 
} 

그리고 XML

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:background="@drawable/mech"> 

    <LinearLayout 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_centerInParent="true" 
     android:gravity="center_horizontal" 
     android:orientation="vertical"> 

     <TextView 
      android:id="@+id/title_1" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:text="@string/slide_1_title" 
      android:textColor="@android:color/white" 
      android:textSize="@dimen/slide_title" 
      android:textStyle="bold" /> 

     <TextView 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:layout_marginTop="20dp" 
      android:paddingLeft="@dimen/desc_padding" 
      android:paddingRight="@dimen/desc_padding" 
      android:text="@string/slide_1_desc" 
      android:textAlignment="center" 
      android:textColor="@android:color/white" 
      android:textSize="@dimen/slide_desc" /> 

    </LinearLayout> 
</RelativeLayout> 

그리고 스택 추적

04-08 20:23:08.386 20697-20697/com.example.introslider E/AndroidRuntime: FATAL EXCEPTION: main 
                    Process: com.example.introslider, PID: 20697 
                    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.introslider/com.example.introslider.WelcomeActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setTypeface(android.graphics.Typeface)' on a null object reference 
                     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665) 
                     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726) 
                     at android.app.ActivityThread.-wrap12(ActivityThread.java) 
                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477) 
                     at android.os.Handler.dispatchMessage(Handler.java:102) 
                     at android.os.Looper.loop(Looper.java:154) 
                     at android.app.ActivityThread.main(ActivityThread.java:6119) 
                     at java.lang.reflect.Method.invoke(Native Method) 
                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 
                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 
                     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setTypeface(android.graphics.Typeface)' on a null object reference 
                     at com.example.introslider.WelcomeActivity.onCreate(WelcomeActivity.java:55) 
                     at android.app.Activity.performCreate(Activity.java:6679) 
                     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118) 
                     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2618) 
                     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)  
                     at android.app.ActivityThread.-wrap12(ActivityThread.java)  
                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)  
                     at android.os.Handler.dispatchMessage(Handler.java:102)  
                     at android.os.Looper.loop(Looper.java:154)  
                     at android.app.ActivityThread.main(ActivityThread.java:6119)  
                     at java.lang.reflect.Method.invoke(Native Method)  
                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)  
                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)  

Answer 1

당신은 당신의 TextView에 서체를 설정하고 있지만 TextView을 포함 시켰습니다 R.layout.activity_welcome 레이아웃에 없습니다. 그것이 참조가 null이고 앱이 충돌하는 이유입니다.