我无法在网格视图中设置多个图像？

Question

我正在创建从相机拍摄照片的应用程序。 2.将其URI保存在数据库中3.使用光标和适配器检索图像uri并在网格视图中进行设置。

我收到错误提示为“错误打开跟踪文件：没有这样的文件或目录（2）”，我也看不到任何名称为“我的图像”的文件夹

主要活动

public class MainActivity extends ActionBarActivity {
    private static final int CAMERA_CAPTURE_IMAGE_REQUEST_CODE = 100;
    final int MEDIA_TYPE_IMAGE=2;
    Button click;
    ImageView image;
    Uri fileuri;
    int camera_capture=100;


    GridView gridactivity;
    Gridsource source;
    customiseadapter adapter;
    ArrayList<String> List;

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

        source=new Gridsource(this);
        source.open();

        gridactivity=(GridView) findViewById(R.id.grid_view);

        List=source.getallpath();
        adapter=new customiseadapter(getApplicationContext(),List);
        gridactivity.setAdapter(adapter);


    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        int id = item.getItemId();
        if (id == R.id.Add_button) {
            captureimage();

        }
        return super.onOptionsItemSelected(item);
    }

    private void captureimage() {
        if(cameraavail())
        {
            Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            fileuri = getmediafileuri(MEDIA_TYPE_IMAGE);
            intent.putExtra(MediaStore.EXTRA_OUTPUT , fileuri);
            startActivityForResult(intent, CAMERA_CAPTURE_IMAGE_REQUEST_CODE);
        }
        else
        {
            Toast.makeText(getApplicationContext(), "device with not camera support", Toast.LENGTH_SHORT).show();
        }
    }



    @Override
    protected void onActivityResult(int resultrequest, int resultcode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(resultrequest, resultcode, data);

        if (resultrequest==CAMERA_CAPTURE_IMAGE_REQUEST_CODE) {
            if (resultcode==RESULT_OK) {

                source.createpicture(fileuri.toString());
                ArrayList<String> list1 = source.getallpath();

                customiseadapter adapter1= new customiseadapter(getApplicationContext(), list1);
                gridactivity.setAdapter(adapter1);




            }else if
            (resultcode==RESULT_CANCELED)
            {
                Toast.makeText(getApplicationContext(),
                        "User cancelled image capture", Toast.LENGTH_SHORT)
                        .show();
            }

        }
    }

    private Uri getmediafileuri(int arg) {
        File mediafile= getmediafile(arg);

            return Uri.fromFile(mediafile) ;
        }
    private File getmediafile(int type){
        File mediadir=new File(Environment.getExternalStorageDirectory()+"/myimages");
        if(!mediadir.exists())
        {
            mediadir.mkdir();
        }

        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
                Locale.getDefault()).format(new Date());
        File mediafile;
        if(type==MEDIA_TYPE_IMAGE )
        {
            mediafile= new File(mediadir.getPath() + File.separator + "img_" + timeStamp +".png" );

        }else
        {
            return null;
        }
        return mediafile;
    }

    private boolean cameraavail() {
        if(getApplicationContext().getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA))
        return true;
        else 
            return false;

        }




}

2.Mysqlitehelper

public class Mysqlitehelper extends SQLiteOpenHelper {



    public static final String Table_grid ="gridtable";
     public static final String column_ID ="ID";
     public static final String column_URI ="URI";

     public static  final String DB_name = "Griddb";
     public static  final int version =1;
     public static  final String Database_create = "create table "+Table_grid+ " (" 
             + column_ID +" integer primary key autoincrement," 
              + column_URI + " text not null);";


     public Mysqlitehelper(Context context) {
            super(context, DB_name, null, version);
                    }


    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(Database_create);

    }


    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS"+ Table_grid);
        onCreate(db);
    }


}

3.自定义适配器

public class customiseadapter extends BaseAdapter {
    Context context;
    ArrayList<String> list;

    public customiseadapter(Context context, ArrayList<String> list) {
        super();
        this.context = context;
        this.list = list;
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return list.size();
    }

    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return list.get(arg0);
    }

    @Override
    public long getItemId(int arg0) {
        // TODO Auto-generated method stub
        return arg0;
    }

    @Override
    public View getView(int arg0, View arg1, ViewGroup arg2) {
        ImageView image = new ImageView(context);
        Uri uri = Uri.parse(list.get(arg0));
        image.setImageURI(uri);
        image.setScaleType(ImageView.ScaleType.CENTER_CROP);
        image.setLayoutParams(new GridView.LayoutParams(70, 70));
        return image;
    }

}

1. 网格源

    public class Gridsource { Mysqlitehelper mydbhelper; SQLiteDatabase database; String[] column_name={Mysqlitehelper.column_ID,Mysqlitehelper.column_URI}; public Gridsource(Context context) { mydbhelper= new Mysqlitehelper(context); } public void open() { database=mydbhelper.getWritableDatabase(); } public void close() { mydbhelper.close(); } public void createpicture(String path) { ContentValues value= new ContentValues(); value.put(Mysqlitehelper.column_URI, path); database.insert(Mysqlitehelper.Table_grid, null, value); } public ArrayList<String>getallpath() { ArrayList<String> pathlist = new ArrayList<String>(); Cursor cursor = database.query(Mysqlitehelper.Table_grid, column_name, null, null, null, null, null, null); if(cursor.moveToFirst()) do{ String path = new String(); path=cursor.getString(1); pathlist.add(path); }while(cursor.moveToNext()); cursor.close(); return pathlist; } } 

请帮助我找到解决方案

Answer 1

您的适配器需要工作。 在您的getView（）方法中，您假设参数是URI。 实际上，这些参数是：

public View getView(final int position, View convertView, final ViewGroup parent) {
...
}

第一个参数是您要渲染的项目在网格视图中的位置。 第二个是视图-可以回收。 第三是视图的父级。 您正在尝试获取该位置（一个简单的整数）并将其用作URI

您应该在getView中执行的操作是将图像从数据库中拉出与“位置”项相对应的图像

请参阅此链接，以获取有关为适配器开发装载程序的更多信息。