问题描述

当从grid view中点击时如何显示指定图像？

我使用一个grid view在程序中显示一些图像：

<?xml version="1.0" encoding="utf-8"?>
<GridView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/gridview"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:numColumns="auto_fit"
    android:verticalSpacing="10dp"
    android:horizontalSpacing="10dp"
    android:columnWidth="90dp"
    android:stretchMode="columnWidth"
    android:gravity="center"
/>

这是处理图像的代码：

public class Gallery extends Activity {
    Integer[] imageIDs = {
            R.drawable.a,
            R.drawable.b,
            R.drawable.c,
            R.drawable.d,
            R.drawable.e,
            R.drawable.f,
            R.drawable.g,
            R.drawable.k,
            R.drawable.j,
            R.drawable.i,
            R.drawable.h,

    };
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.gallery);

        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(getBaseContext(),
                        "pic" + (position + 1) + " selected",
                        Toast.LENGTH_SHORT).show();
            }
        });
    }

    public class ImageAdapter extends BaseAdapter
    {
        private Context context;

        public ImageAdapter(Context c)
        {
            context = c;
        }

        //---returns the number of images---
        public int getCount() {
            return imageIDs.length;
        }

        //---returns the ID of an item---
        public Object getItem(int position) {
            return position;
        }

        public long getItemId(int position) {
            return position;
        }

        //---returns an ImageView view---
        public View getView(int position, View convertView, ViewGroup parent)
        {
            ImageView imageView;
            if (convertView == null) {
imageView = new ImageView(context);
                imageView.setLayoutParams(new GridView.LayoutParams(185, 185));
                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                imageView.setPadding(5, 5, 5, 5);
            } else {
                imageView = (ImageView) convertView;
            }
            imageView.setImageResource(imageIDs[position]);
            return imageView;
        }
    }
}

当从屏幕上点击时，我想以实际大小来显示指定的图像。如何实现?

解决方案

我之前在新的 activity 中显示图像，是这么实现的：

public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
    Intent intent = new Intent(Gallery.this, DisplayActivity.class);
    intent.putExtra("Image Int", imageIDs[position]);
    startActivity(intent);
}

在 activity 中使用：

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.display);

    int imageInt = getIntent().getIntExtra("Image Int", R.drawable.oops); // oops should be a fallback if an error happens
    ImageView imageView = (ImageView) findViewById(R.id.imageView);
    imageView.setImageResource(imageInt);
}

解决方案二：

点击可以弹出一个Dialog或者Dialog风格的Activity,至于要想显示实际大小，那么你首先得得到image的长和宽。
int width = bitmap.getWidth();
int height = bitmap.getHeight();
然后在你要显示的View去设置imageView.setLayoutParams(new ViewGroup.LayoutParams(width, height));

解决方案三：

你是就想在gridview中放大么，那样效果会不太好如果实现
不如用dialog去显示