myView is never initialized and thus null myView.invalidate(); causes NullPointerException as a result
On Apr 1, 11:09 am, mack2978 <[email protected]> wrote: > logs: > Thread [<1> main] (Suspended (exception NullPointerException)) > HelloGridView$1.onItemClick(AdapterView, View, int, long) line: 38 > GridView(AdapterView).performItemClick(View, int, long) line: 284 > AbsListView$PerformClick.run() line: 1696 > ViewRoot(Handler).handleCallback(Message) line: 587 > ViewRoot(Handler).dispatchMessage(Message) line: 92 > Looper.loop() line: 123 > ActivityThread.main(String[]) line: 4627 > Method.invokeNative(Object, Object[], Class, Class[], Class, int, > boolean) line: not available [native method] > Method.invoke(Object, Object...) line: 521 > ZygoteInit$MethodAndArgsCaller.run() line: 868 > ZygoteInit.main(String[]) line: 626 > NativeStart.main(String[]) line: not available [native method] > > On Apr 1, 1:54špm, Kostya Vasilyev <[email protected]> wrote: > > > Logcat output? > > 01.04.2011 12:04 ÐÏÌØÚÏ×ÁÔÅÌØ "mack2978" <[email protected]> ÎÁÐÉÓÁÌ: > > > > Hi All, > > > > I am trying to show full image when clicking on one of the thumbnail > > > of grid view, i am able to view the grid with thumbnails but as soon > > > as i click on any thumbnail to show it in full screen, handling > > > onItemClick(), it crashes. below is my complete code, please help > > > > package com.example.HelloGridView; > > > > import android.app.Activity; > > > import android.os.Bundle; > > > import android.content.Context; > > > import android.content.res.Resources; > > > import android.graphics.Bitmap; > > > import android.graphics.Canvas; > > > import android.graphics.Paint; > > > import android.graphics.drawable.Drawable; > > > import android.util.AttributeSet; > > > import android.view.View; > > > import android.view.ViewGroup; > > > import android.widget.AdapterView; > > > import android.widget.AdapterView.OnItemClickListener; > > > import android.widget.BaseAdapter; > > > import android.widget.GridView; > > > import android.widget.ImageView; > > > import android.widget.Toast; > > > > public class HelloGridView extends Activity{ > > > int current_pos; > > > private Bitmap[] mTileArray; > > > private MyView myView; > > > /** Called when the activity is first created. */ > > > @Override > > > public void onCreate(Bundle savedInstanceState) { > > > super.onCreate(savedInstanceState); > > > setContentView(R.layout.main); > > > GridView gridview = (GridView) findViewById(R.id.gridview); > > > gridview.setAdapter(new ImageAdapter(this)); > > > gridview.setOnItemClickListener(new OnItemClickListener() { > > > public void onItemClick(AdapterView<?> parent, View v, int > > > position, long id) > > > { > > > Toast.makeText(HelloGridView.this, "" + position, > > > Toast.LENGTH_SHORT).show(); > > > current_pos = position; > > > myView.invalidate(); > > > } > > > }); > > > > } > > > > public class ImageAdapter extends BaseAdapter { > > > private Context mContext; > > > > public ImageAdapter(Context c) { > > > mContext = c; > > > } > > > > public int getCount() { > > > return mThumbIds.length; > > > } > > > > public Object getItem(int position) { > > > return null; > > > } > > > > public long getItemId(int position) { > > > return 0; > > > } > > > > // create a new ImageView for each item referenced by the > > > Adapter > > > public View getView(int position, View convertView, ViewGroup > > > parent) { > > > ImageView imageView; > > > if (convertView == null) { // if it's not recycled, > > > initialize some attributes > > > imageView = new ImageView(mContext); > > > imageView.setLayoutParams(new > > > GridView.LayoutParams(85, 85)); > > > > imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); > > > imageView.setPadding(8, 8, 8, 8); > > > } else { > > > imageView = (ImageView) convertView; > > > } > > > > imageView.setImageResource(mThumbIds[position]); > > > return imageView; > > > } > > > > // references to our images > > > private Integer[] mThumbIds = { > > > R.drawable.sample_0, R.drawable.sample_1, > > > R.drawable.sample_2, R.drawable.sample_0 > > > }; > > > } > > > > public class MyView extends View { > > > > private Bitmap[] mTileArray; > > > private final Paint mPaint = new Paint(); > > > > public MyView(Context context, AttributeSet attrs, int > > > defStyle) { > > > super(context, attrs, defStyle); > > > > //TypedArray a = context.obtainStyledAttributes(attrs, > > > R.styleable.TileView); > > > // mTileSize = a.getInt(R.styleable.TileView_tileSize, 12); > > > //a.recycle(); > > > Resources r = this.getContext().getResources(); > > > loadTile(0, > > > r.getDrawable(R.drawable.sample_0)); > > > loadTile(1, r.getDrawable(R.drawable.sample_1)); > > > loadTile(2, r.getDrawable(R.drawable.sample_2)); > > > loadTile(3, r.getDrawable(R.drawable.sample_0)); > > > } > > > > public MyView(Context context, AttributeSet attrs) { > > > super(context, attrs); > > > > Resources r = this.getContext().getResources(); > > > loadTile(0, > > > r.getDrawable(R.drawable.sample_0)); > > > loadTile(1, r.getDrawable(R.drawable.sample_1)); > > > loadTile(2, r.getDrawable(R.drawable.sample_2)); > > > loadTile(3, r.getDrawable(R.drawable.sample_0)); > > > } > > > > public void loadTile(int key, Drawable tile) { > > > Bitmap bitmap = Bitmap.createBitmap(191, 285, > > > Bitmap.Config.ARGB_8888); > > > Canvas canvas = new Canvas(bitmap); > > > tile.setBounds(0, 0, 191, 285); > > > tile.draw(canvas); > > > mTileArray[key] = bitmap; > > > } > > > > @Override > > > public void onDraw(Canvas canvas) { > > > super.onDraw(canvas); > > > canvas.drawBitmap(mTileArray[1], 0,0, mPaint); > > > > } > > > > } > > > > } > > > > -- > > > You received this message because you are subscribed to the Google > > > Groups "Android Developers" group. > > > To post to this group, send email to [email protected] > > > To unsubscribe from this group, send email to > > > [email protected] > > > For more options, visit this group at > > >http://groups.google.com/group/android-developers?hl=en-Hide quoted text - > > > - Show quoted text - -- You received this message because you are subscribed to the Google Groups "Android Developers" group. 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