android - 在android中的gridview中拖放图像

Question

我正在开发一个示例 android 应用程序以了解 android 中的拖放操作。在应用程序启动时，我在 GridView 中显示了一些图像。现在我需要一次将一张图片拖到另一张图片的位置。将一张图片放在另一张图片上后，图片应该交换位置。我怎样才能实现它？请指导/帮助我。

Answer 1

您可以使用 thquinn 的 DraggableGridView 轻松实现此目的

您可以添加自定义布局

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);

    }
}