我如何使用 fileinputstream 填充 listView 中的 imageview

Question

我使用 FileoutputStream 将相机图像输出到 sdCard，然后我想使用 fileInputStream 在 listView 中填充 imageView。所以这是我的代码注释，我已经更改了我的一台计算机的路径以与模拟器一起使用。

public class CameraAPI extends Activity implements SurfaceHolder.Callback{

public Camera camera;
MediaRecorder mediaRecorder;
CBDataBaseHelper RH;
TextView RecipeID;

public void onCreate (Bundle savedInstanceState){
    boolean diditwork;
    try{

    super.onCreate(savedInstanceState);
    setContentView(R.layout.camera);

    RecipeID = (TextView)findViewById(R.id.Rid2);
    String RowID;
    Bundle extras = getIntent().getExtras();    
    RowID = extras.getString("SELECTED2");
    RecipeID.setText(RowID);
    SurfaceView surface = (SurfaceView)findViewById(R.id.acccam);
    SurfaceHolder holder = surface.getHolder();
    holder.addCallback(this);
    holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}catch(Exception e){
    diditwork = false;
    String error = e.toString();
    Dialog d = new Dialog(this);
    d.setTitle("darn");
    TextView tv = new TextView(this);
    tv.setText(error);
    d.setContentView(tv);
    d.show();
}}

        public void takePhoto(View view){
            //String ID = RecipeID.getText().toString();
            //Long LID = Long.parseLong(ID);
            boolean diditwork;
            try{
            takePicture();
            }catch(Exception e){
                diditwork = false;
                String error = e.toString();
                Dialog d = new Dialog(this);
                d.setTitle("darn");
                TextView tv = new TextView(this);
                tv.setText(error);
                d.setContentView(tv);
                d.show();
            }
            //String path = "/sdcard/Image.jpg";
            //RH.updateRecipe3(LID,path);

    }




public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
    // TODO Auto-generated method stub

}



public void surfaceCreated(SurfaceHolder holder) {
    // TODO Auto-generated method stub
    if (mediaRecorder == null){
        try{
            camera = camera.open();
            camera.setPreviewDisplay(holder);
            camera.startPreview();

        }catch (IOException e){
            Log.d("CAMERA", e.getMessage());
        }

    }
}



public void surfaceDestroyed(SurfaceHolder holder) {
    // TODO Auto-generated method stub
    camera.stopPreview();
    camera.release();
}

public void takePicture(){
boolean diditwork;
    try{
    camera.takePicture(shutterCallback, rawCallback, jpegCallback);
    }catch(Exception e){
        diditwork = false;
        String error = e.toString();
        Dialog d = new Dialog(this);
        d.setTitle("darn");
        TextView tv = new TextView(this);
        tv.setText(error);
        d.setContentView(tv);
        d.show();
    }
}


ShutterCallback shutterCallback= new ShutterCallback()
{
    public void onShutter(){

    }
};

    PictureCallback rawCallback = new PictureCallback(){
        public void onPictureTaken(byte[] data, Camera camera){

        }
    };

    PictureCallback jpegCallback = new PictureCallback(){
        public void onPictureTaken(byte[] data, Camera camera){
            FileOutputStream outStream = null;

            try{
                outStream = new FileOutputStream("//STEFAN-PC/Users/stefan/Desktop/Uni Work/Image.jpg");
                outStream.write(data);
                outStream.close();
            }catch(FileNotFoundException e){
                Log.d("CAMERA", e.getMessage());
            }catch(IOException e){
                Log.d("CAMERA",e.getMessage());
            }
                /*RH = new CBDataBaseHelper(CameraAPI.this);
                RH.open();
                String ID = RecipeID.getText().toString();
                Long RID = Long.parseLong(ID);
                RH.updateRecipe3(RID, data);
                RH.close();*/
            String ID = RecipeID.getText().toString();
            Long RID = Long.parseLong(ID);
            RH.updateRecipe3(RID, "/sdcard/Image.jpg");
            }







};
}

然后这是我在哪里填充 listView 的代码，任何人都可以给我一个指针或布局代码片段来说明如何将图像加载到 imageView 中吗？

public class CBFilter extends ListActivity {

ListView RecipeNames;
Cursor cursor;
SimpleCursorAdapter adapter;
CBDataBaseHelper data;
SQLiteDatabase data2;
TextView RecipeText, RowId;
String[] from = { CBDataBaseHelper.KEY_NAME};
int[] to = { R.id.row};
ImageView image;
byte[] dataImage;

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);
setContentView(R.layout.main);
boolean diditwork;
try{

//java.io.FileInputStream in = openFileInput("myImage.jpg");
RecipeNames = (ListView) findViewById(android.R.id.list);
RecipeNames.setTextFilterEnabled(true);
RecipeText = (TextView) findViewById(R.id.recipeText);
adapter = new SimpleCursorAdapter (this, 0, cursor, null, null);
image = (ImageView) findViewById(R.id.RecipeImage);

data = new CBDataBaseHelper(this);
data.open();
cursor = data.query();
startManagingCursor(cursor);
adapter = new SimpleCursorAdapter(this, R.layout.row, cursor, from, to);
RecipeNames.setAdapter(adapter);
adapter.notifyDataSetChanged();




}catch(Exception e){
diditwork = false;
String error = e.toString();
Dialog d = new Dialog(this);
d.setTitle("darn");
TextView tv = new TextView(this);
tv.setText(error);
d.setContentView(tv);
d.show();
}}

public void CreateNew(View view){

    Intent myIntent = new Intent(this, CBCreate.class);
    startActivity(myIntent);
}

@Override
public void onListItemClick(ListView parent, View v, int position, long id) {
    super.onListItemClick(parent, v, position, id);
    Intent intent1 = new Intent(this, CBCreate.class);
    long rowId = cursor.getLong(cursor.getColumnIndex(CBDataBaseHelper.KEY_ROWID));
    String s = String.valueOf(rowId);
    intent1.putExtra("SELECTED", s);
    startActivity(intent1);
}


}

谢谢斯特凡

Answer 1

设置ImageView显示SD卡中的图像

ImageView imageView;
Bitmap bmp = BitmapFactory.decodeFile(imagePath);
imageView.setImageBitmap(bmp);

但是如果你想在ListView中显示ImageView，你必须为ListView定义自己的适配器，并且最好使用View Holder模式来提高性能。

public class MyArrayAdapter extends ArrayAdapter<String> {
    private final Activity context;
    private final String[] names;

    public MyArrayAdapter(Activity context, String[] names) {
        super(context, R.layout.rowlayout, names);
        this.context = context;
        this.names = names;
    }

    // static to save the reference to the outer class and to avoid access to
    // any members of the containing class
    static class ViewHolder {
        public ImageView imageView;
        public TextView textView;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // ViewHolder will buffer the assess to the individual fields of the row
        // layout

        ViewHolder holder;
        // Recycle existing view if passed as parameter
        // This will save memory and time on Android
        // This only works if the base layout for all classes are the same
        View rowView = convertView;
        if (rowView == null) {
            LayoutInflater inflater = context.getLayoutInflater();
            rowView = inflater.inflate(R.layout.rowlayout, null, true);
            holder = new ViewHolder();
            holder.textView = (TextView) rowView.findViewById(R.id.label);
            holder.imageView = (ImageView) rowView.findViewById(R.id.icon);
            rowView.setTag(holder);
        } else {
            holder = (ViewHolder) rowView.getTag();
        }

        holder.textView.setText(names[position]);
        // Change the icon for Windows and iPhone
        String s = names[position];

        Bitmap bmp = BitmapFactory.decodeFile(imagePath);
        holder.imageView.setImageBitmap(bmp);           

        return rowView;
    }
}

查看本教程了解如何使用 View Holder 模式。

希望这有帮助。