在Android中的应用程序库中显示图片-Java 学习之路

我正在编写一个应用程序，用户将点击应用程序中的按钮，图库将弹出，用户将从库中选择一个图像，所选图像应该显示在我放置在图像上的图像中 . 屏幕 . 当我单击按钮弹出库时，我选择了一个图像，但由于某种原因，该图像没有显示在我的应用程序屏幕上 . 非常感谢您的帮助 . 我只添加了两个权限，如下所示：

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

这是我的代码：

public class MainActivity extends AppCompatActivity {

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

    public void showPicture(View view) {
        Intent intent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
        if (intent.resolveActivity(getPackageManager()) != null) {
            startActivityForResult(intent, 1);
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 1 && resultCode == RESULT_OK && null != data) {
            Uri photoUri = data.getData();
            Bitmap selectedImage = null;

            try{
                selectedImage = MediaStore.Images.Media.getBitmap(this.getContentResolver(), photoUri);
            } catch (Exception e){
                e.printStackTrace();
            }
            ImageView imageView = (ImageView) findViewById(R.id.image);
            imageView.setImageBitmap(selectedImage);
        }
    }
}

编辑：我尝试了答案中给出的代码，但是我的堆栈跟踪中出现以下错误 . 为简洁起见，仅显示RuntimeExceptions：

java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=Intent { dat=content://media/external/images/media/46 }} to activity {cs193a.stanford.edu.testproject/cs193a.stanford.edu.testproject.MainActivity}: java.lang.SecurityException: Permission Denial: reading com.android.providers.media.MediaProvider uri content://media/external/images/media/46 from pid=2754, uid=10059 requires android.permission.READ_EXTERNAL_STORAGE, or grantUriPermission()

                                                                            Caused by: java.lang.SecurityException: Permission Denial: reading com.android.providers.media.MediaProvider uri content://media/external/images/media/46 from pid=2754, uid=10059 requires android.permission.READ_EXTERNAL_STORAGE, or grantUriPermission()

在我的代码中似乎有问题的唯一代码行再次是声明Cursor的行 . 非常感谢你的帮助

1 回答

要打开图库

Intent i = new Intent(
Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);

startActivityForResult(i, RESULT_LOAD_IMAGE);

要取回结果：

@Override
protected void onActivityResult(final int requestCode, final int resultCode, final Intent imageReturnedIntent) {
    // TODO Auto-generated method stub
      super.onActivityResult(requestCode, resultCode, imageReturnedIntent);   

        switch(requestCode) {  
        case RESULT_LOAD_IMAGE:  
            if(resultCode == RESULT_OK)  
            {  
                Uri uri = imageReturnedIntent.getData();  
                String[] projection = {MediaStore.Images.Media.DATA};  

                Cursor cursor = getContentResolver().query(uri, projection, null, null, null);  
                cursor.moveToFirst();

                int columnIndex = cursor.getColumnIndex(projection[0]);  
                String filePath = cursor.getString(columnIndex);  
                cursor.close();
                Bitmap image = BitmapFactory.decodeFile(filePath);

                ImageView im = (ImageView)findViewById(R.id.imagev);
               im.setImageBitmap(image);
            }  
        }  
    }

编辑：请现在试试

回复于 2024-05-07T17:16:12+08:00

在Android中的应用程序库中显示图片

1 回答

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