Drag and drop images in gridview in android

问题

I'am developing a sample android application to learn about drag & drop in android. On start of the app, i'am displaying few images on a grid view. Now i need to drag one image at a time over to the place of another. After dropping an image over another, the images should swap its places. How can i achieve it ? Please guide/help me.

回答1:

You can easily achieve this by using thquinn's DraggableGridView

You can add your custom layout

public class DraggableGridViewSampleActivity extends Activity {
    static Random random = new Random();
    static String[] words = "the of and a to in is be that was he for it with as his I on have at by not they this had are but from or she an which you one we all were her would there their will when who him been has more if no out do so can what up said about other into than its time only could new them man some these then two first may any like now my such make over our even most me state after also made many did must before back see through way where get much go well your know should down work year because come people just say each those take day good how long Mr own too little use US very great still men here life both between old under last never place same another think house while high right might came off find states since used give against three himself look few general hand school part small American home during number again Mrs around thought went without however govern don't does got public United point end become head once course fact upon need system set every war put form water took".split(" ");
    DraggableGridView dgv;
    Button button1, button2;
    ArrayList<String> poem = new ArrayList<String>();

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        dgv = ((DraggableGridView)findViewById(R.id.vgv));
        button1 = ((Button)findViewById(R.id.button1));
        button2 = ((Button)findViewById(R.id.button2));

        setListeners();
    }
    private void setListeners()
    {
        dgv.setOnRearrangeListener(new OnRearrangeListener() {
            public void onRearrange(int oldIndex, int newIndex) {
                String word = poem.remove(oldIndex);
                if (oldIndex < newIndex)
                    poem.add(newIndex, word);
                else
                    poem.add(newIndex, word);
            }
        });
        dgv.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> arg0, View view, int position, long arg3) {
                Toast.makeText(getApplicationContext(), "On clicked" +position, Toast.LENGTH_SHORT).show();
                dgv.removeViewAt(position);
                poem.remove(position);
            }
        });
        button1.setOnClickListener(new OnClickListener() {
            public void onClick(View arg0) {
                String word = words[random.nextInt(words.length)];
                addView();
                poem.add(word);
            }
        });
        button2.setOnClickListener(new OnClickListener() {
            public void onClick(View arg0) {
                String finishedPoem = "";
                for (String s : poem)
                    finishedPoem += s + " ";
                new AlertDialog.Builder(DraggableGridViewSampleActivity.this)
                .setTitle("Here's your poem!")
                .setMessage(finishedPoem).show();
            }
        });
    }

    public void addView()
    {

        LayoutParams mLayoutParams= new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

        LinearLayout mLinearLayout= new LinearLayout(DraggableGridViewSampleActivity.this);
        mLinearLayout.setOrientation(LinearLayout.VERTICAL);
        mLinearLayout.setGravity(Gravity.CENTER_HORIZONTAL);

        ImageView mImageView = new ImageView(DraggableGridViewSampleActivity.this);

        if(dgv.getChildCount()%2==0)
            mImageView.setImageResource(R.drawable.child1);
        else
            mImageView.setImageResource(R.drawable.child2);

        mImageView.setScaleType(ImageView.ScaleType.FIT_XY);
        mImageView.setLayoutParams(mLayoutParams);

        mImageView.setId(dgv.getChildCount());

        mImageView.setOnTouchListener(new OnTouchListener() {

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                // TODO Auto-generated method stub
                Toast.makeText(getApplicationContext(), v.getId()+"clicked ", Toast.LENGTH_SHORT).show();
                return dgv.onTouch(v, event);
            }
        });


            TextView mTextView = new TextView(DraggableGridViewSampleActivity.this);

            mTextView.setLayoutParams(mLayoutParams);

            mTextView.setOnTouchListener(new OnTouchListener() {

                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    // TODO Auto-generated method stub
                    Toast.makeText(getApplicationContext(), v.getId()+"clicked text ", Toast.LENGTH_SHORT).show();
                    return dgv.onTouch(v, event);
                }
            });

            TextView mTextViewLabel = new TextView(DraggableGridViewSampleActivity.this);

            mTextViewLabel.setText(((dgv.getChildCount()+1)+""));
            mTextViewLabel.setLayoutParams(mLayoutParams);

            mTextViewLabel.setId(dgv.getChildCount());

            mTextViewLabel.setOnTouchListener(new OnTouchListener() {

                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    Toast.makeText(getApplicationContext(), v.getId()+"clicked text ", Toast.LENGTH_SHORT).show();
                    return dgv.onTouch(v, event);
                }
            });

            mLinearLayout.setTag(mTextViewLabel);
            mLinearLayout.addView(mTextViewLabel);
            mLinearLayout.addView(mImageView);
            mLinearLayout.addView(mTextView);
        dgv.addView(mLinearLayout);

    }
}

来源：https://stackoverflow.com/questions/10846240/drag-and-drop-images-in-gridview-in-android