如何在 Gridview 中使用新活动单击图片时放大图片

Question

所以我有一个使 GridView 膨胀的活动，我希望它是可单击的，单击后，它会打开一个新活动，显示整个图像，以及我在另一个活动中写入的一些文本。请注意，已确认写入的txt文件已成功写入，并且该文件位于SD卡中。

下面是 GridView 活动的代码

public class GridView extends AppCompatActivity {
android.widget.GridView gv;
ArrayList<File> list,list2;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.gallery);
    File dir = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/MyCameraApp");
    File dir2 = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/MyCameraApp");
    list = imageReader(dir);
    list2 = locationReader(dir2);

    gv = (android.widget.GridView) findViewById(R.id.gridView);
    gv.setAdapter(new GridAdapter());
    gv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Intent intent = new Intent(GridView.this, ViewImage.class);
            intent.putExtra("MyImage", list.get(position));
            intent.putExtra("MyLocation", list2.get(position));
            startActivity(intent);
            //startActivity(new Intent(getApplicationContext(), ViewImage.class).putExtra("img",list.get(position)));
        }
    });
}
public void BackToMain(View view) {
    Intent backToMain = new Intent(this, MainActivity.class);
    startActivity(backToMain);
}
class GridAdapter extends BaseAdapter{
    @Override
    public int getCount() {
        return list.size();
    }
    @Override
    public Object getItem(int position) {
        return list.get(position);
    }
    @Override
    public long getItemId(int position) {
        return 0;
    }
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        convertView = getLayoutInflater().inflate(R.layout.simple_grid, parent, false);
        ImageView iv = (ImageView) convertView.findViewById(R.id.imageView);
        iv.setImageURI(Uri.parse(getItem(position).toString()));
        return convertView;
    }
}

ArrayList<File> imageReader(File root){
    ArrayList<File> a = new ArrayList<>();
    File[] files = root.listFiles();
    for(int i = 0; i < files.length; i++){
        if(files[i].isDirectory()){
        }
        else
        {
            if(files[i].getName().endsWith(".jpg")){
                a.add(files[i]);
            }
        }
    }
    return a;
}
ArrayList<File> locationReader(File root){
    ArrayList<File> a = new ArrayList<>();
    File[] files = root.listFiles();
    for(int i = 0; i < files.length; i++){
        if(files[i].isDirectory()){
        }
        else
        {
            if(files[i].getName().endsWith(".txt")){
                a.add(files[i]);
            }
        }
    }
    return a;
}
}

这是 GridView 调用的活动，它应该显示图像并打开我之前写入的文件，并显示其内容（字符串）。

public class ViewImage extends AppCompatActivity {
ImageView imageView;
TextView textView;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.view_image);
 //   int image = getIntent().getExtras().getInt("MyImage", R.drawable.common_google_signin_btn_text_light);
    int image = getIntent().getIntExtra("MyImage", R.drawable.cast_ic_notification_0);
    ImageView imageView = (ImageView) findViewById(R.id.imageView2);
    imageView.setImageResource(image);
    Intent calledActivity = getIntent();
    String pos = calledActivity.getExtras().getString("MyLocation");
    textView = (TextView) findViewById(R.id.text_location);
    textView.setText(pos);
}
public void BackToCamera(View view) {
    Intent intent = new Intent(ViewImage.this, MainActivity.class);
    startActivity(intent);
}
}

现在，我所看到的只是R.drawable.cast_ic_notification_0图片，而不是GridView的图像。另外，TextView 是空的，我使用了调试器，它显示

String pos = calledActivity.getExtras().getString("MyLocation");

POS 为空。请帮忙！

Answer 1

list.get(position)是一个文件，你试图将其读取为 getExtras（）.getInt（）

我认为您应该将文件路径作为字符串传递：

intent.putExtra("MyImage", list.get(position).getAbsolutePath());

并接收它：

File imgFile = new  File(getIntent().getStringExtra("MyImage"));
if(imgFile.exists()){
    Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath());
    ImageView imageView = (ImageView) findViewById(R.id.imageView2);
    imageView.setImageBitmap(myBitmap);
}