從imageview傳遞圖像到第二個活動時出錯

Question

所以我有一個imageview1，當它被點擊一個新的活動時，在下一個活動的相同圖像顯示在新的imageview2上時開始。被點擊的imageview1被我的mainactivity上的listview訪問。列表視圖由一個數組填充，每個列表視圖項都有一個相應的圖像。

所以，當一個列表視圖項被點擊時，它開始一個新的活動imageview1駐留。該imageview使用引用可繪製圖像的xml typedarray進行填充。

我無法將圖像從我的第一個imageview傳遞到下一個新的活動。我得到一個空指針異常，我已經在下面列出了。我對編程非常陌生，我不確定如何解決這個問題。任何幫助將非常感激。

我的繼承人routeDetails類，其中包含第一ImageView的

public class RouteDetails extends AppCompatActivity { 

ImageView routeImage; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_route_details); 

    //TextView for route details 
    final TextView routeDetailsView = (TextView) findViewById(R.id.routeDetailsView); 
    routeDetailsView.setText(getIntent().getExtras().getString("route")); 

    //ImageView for route details 
    routeImage = (ImageView) findViewById(R.id.routeImage); 
    routeImage.setImageResource(getIntent().getIntExtra("imageResourceId", 0)); 


    //passing image to fullscreenimage 
    routeImage.setDrawingCacheEnabled(true); 
    routeImage.buildDrawingCache(); 
    final Bitmap bitmap = routeImage.getDrawingCache(); 

////////// Trying to pass image to new activity 

    routeImage.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View view) 
     { 
      Intent i = new Intent(RouteDetails.this, FullScreenImage.class); 
      //Bitmap _bitmap; // your bitmap 
      ByteArrayOutputStream _bs = new ByteArrayOutputStream(); 
      bitmap.compress(Bitmap.CompressFormat.PNG, 50, _bs); 
      i.putExtra("byteArray", _bs.toByteArray()); 
      startActivity(i); 
     } 

    }); 


//////////// 
} 

和我的繼承人fullscreenimage類即時通訊試圖將圖像傳遞到

public class FullScreenImage extends AppCompatActivity { 

TouchImageView routeImageFull; 

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


    setContentView(R.layout.full_screen_image); 
    routeImageFull = (TouchImageView) findViewById(R.id.fullScreenImageView); 


    if(getIntent().hasExtra("byteArray")) { 
     TouchImageView routeImageFull= new TouchImageView(this); 
     Bitmap bitmap = BitmapFactory.decodeByteArray(
       getIntent().getByteArrayExtra("byteArray"),0,getIntent().getByteArrayExtra("byteArray").length); 
     routeImageFull.setImageBitmap(bitmap); 
    } 
} 
} 

和繼承人的錯誤即時得到

E/AndroidRuntime: FATAL EXCEPTION: main 
       Process: com.example.zach.listview, PID: 3429 
       java.lang.NullPointerException: Attempt to invoke virtual  method 'boolean  android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int,  java.io.OutputStream)' on a null object reference 
        at  com.example.zach.listview.RouteDetails$1.onClick(RouteDetails.java:47) 
        at android.view.View.performClick(View.java:5610) 
        at android.view.View$PerformClick.run(View.java:22265) 
        at android.os.Handler.handleCallback(Handler.java:751) 
        at android.os.Handler.dispatchMessage(Handler.java:95) 
        at android.os.Looper.loop(Looper.java:154) 
        at  android.app.ActivityThread.main(ActivityThread.java:6077) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755) 

Answer 1

而不是傳遞整個位圖。您可以簡單地將您在此處獲得的資源ID發送給其他活動，並且可以通過相同的方式顯示圖像，您在此處執行操作。以下是更改後的代碼。

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_route_details); 

    //TextView for route details 
    final TextView routeDetailsView = (TextView)  
    findViewById(R.id.routeDetailsView); 
    routeDetailsView.setText(getIntent().getExtras().getString("route")); 

    //ImageView for route details 
    routeImage = (ImageView) findViewById(R.id.routeImage); 

    int mImageResource = getIntent().getIntExtra("imageResourceId", 0); 
    routeImage.setImageResource(mImageResource); 


    //passing image to fullscreenimage 
    routeImage.setDrawingCacheEnabled(true); 
    routeImage.buildDrawingCache(); 
    final Bitmap bitmap = routeImage.getDrawingCache(); 

    // Trying to pass image to new activity 

    routeImage.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View view) 
     { 
      Intent i = new Intent(RouteDetails.this,FullScreenImage.class); 
      i.putExtra("mImageResource", mImageResource); 
      startActivity(i); 
     } 

    }); 
}