Question

我有一个gridView，可以从sdcard / dcim / camera加载图像并显示它们。我想在图像上放置onclick监听器，当我点击它时，它会在其他活动中打开该图片。当我点击它时，如何从gridView获取图像。错误在这一行： intent.putExtra（＆＃34; image＆＃34;，item.getImage（））; 我该如何解决这个问题？或者我怎样才能使其发挥作用？

    public class MainActivity extends Activity {

        ImageAdapter myImageAdapter;

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

            GridView gridview = (GridView) findViewById(R.id.gridView);
            myImageAdapter = new ImageAdapter(this);
            gridview.setAdapter(myImageAdapter);

            gridview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
                    ImageItem item = (ImageItem) parent.getItemAtPosition(position);

                    //Create intent
                    Intent intent = new Intent(MainActivity.this, DetailsActivity.class);
                    intent.putExtra("image", item.getImage()); // ERROR IS ON ITEM.GETIMAGE

                    //Start details activity
                    startActivity(intent);
                }
            });
            String ExternalStorageDirectoryPath = Environment
                    .getExternalStorageDirectory()
                    .getAbsolutePath();

            String targetPath = ExternalStorageDirectoryPath + "/DCIM/Camera/";

            Toast.makeText(getApplicationContext(), targetPath, Toast.LENGTH_LONG).show();
            File targetDirector = new File(targetPath);

            File[] files = targetDirector.listFiles();
            for (File file : files){
                myImageAdapter.add(file.getAbsolutePath());
            }
        }

    }

// ***************************************** /

public class ImageItem {
    private Bitmap image;
    private String title;

    public ImageItem(Bitmap image ) {
        super();
        this.image = image;
    }

    public Bitmap getImage() {
        return image;
    }

    public void setImage(Bitmap image) {
        this.image = image;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }
}

// *********** ******* /

public class ImageAdapter extends BaseAdapter {

    private Context mContext;
    ArrayList<String> itemList = new ArrayList<String>();

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

    void add(String path){
        itemList.add(path);
    }

    @Override
    public int getCount() {
        return itemList.size();
    }

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

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView;
        if (convertView == null) {  // if it's not recycled, initialize some attributes
            imageView = new ImageView(mContext);
            imageView.setLayoutParams(new GridView.LayoutParams(220, 220));
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            imageView.setPadding(8, 8, 8, 8);
        } else {
            imageView = (ImageView) convertView;
        }

        Bitmap bm = decodeSampledBitmapFromUri(itemList.get(position), 220, 220);

        imageView.setImageBitmap(bm);
        return imageView;
    }

    public Bitmap decodeSampledBitmapFromUri(String path, int reqWidth, int reqHeight) {

        Bitmap bm = null;
        // First decode with inJustDecodeBounds=true to check dimensions
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(path, options);

        // Calculate inSampleSize
        options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;
        bm = BitmapFactory.decodeFile(path, options);

        return bm;
    }

    public int calculateInSampleSize(

            BitmapFactory.Options options, int reqWidth, int reqHeight) {
        // Raw height and width of image
        final int height = options.outHeight;
        final int width = options.outWidth;
        int inSampleSize = 1;

        if (height > reqHeight || width > reqWidth) {
            if (width > height) {
                inSampleSize = Math.round((float)height / (float)reqHeight);
            } else {
                inSampleSize = Math.round((float)width / (float)reqWidth);
            }
        }

        return inSampleSize;
    }

}

// *********** ** /

public class DetailsActivity extends Activity {

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

        Bitmap bitmap = getIntent().getParcelableExtra("image");


        ImageView imageView = (ImageView) findViewById(R.id.image1);
        imageView.setImageBitmap(bitmap);
    }
}

// *********** ********** /

activity_main.xml中

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#f0f0f0">

    <GridView
        android:id="@+id/gridView"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:columnWidth="150dp"
        android:drawSelectorOnTop="true"
        android:gravity="center"
        android:numColumns="auto_fit"
        android:stretchMode="columnWidth"
        android:verticalSpacing="5dp"
        android:focusable="true"
        android:clickable="true"/>

</RelativeLayout>

// *********** **** /

details_activity.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="#000">

    <ImageView
        android:id="@+id/image1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        android:scaleType="fitCenter" />


</FrameLayout>

Answer 1

在活动之间传递位图是不好的做法。

要做的合乎逻辑的事情是将图像路径传递给下一个活动，然后根据图像视图尺寸解码该活动中的图像。

我希望这很有帮助。：）

如何从gridView获取图像（位图）

1 个答案: