图像视图消失了?

Question

我刚刚做了一个新的项目，但是当我在我的布局中添加一个图像视图并启动模拟器时， 我找不到它。我的目标是，让用户点击图像视图，然后将他定向到图库，然后他选择图片，然后将其保存在数据库中，就这么简单。但是当我启动我的应用程序时，我只是找不到图像视图。对正在发生的事情有什么想法吗？

这是我的布局：

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<ImageView
android:id="@+id/imageVieww"
android:layout_width="148dp"
android:layout_height="160dp"
app:layout_constraintBottom_toTopOf="@+id/Arabic"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.498"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:srcCompat="@drawable/galboy" />
<EditText
android:id="@+id/Arabic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Arabic"
android:inputType="textPersonName"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.497"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.268" />
<EditText
android:id="@+id/Long"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Long"
android:inputType="textPersonName"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.497"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/English"
app:layout_constraintVertical_bias="0.071" />
<EditText
android:id="@+id/Mob"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Mob"
android:inputType="textPersonName"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.497"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/Lat"
app:layout_constraintVertical_bias="0.072" />
<EditText
android:id="@+id/user"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Username"
android:inputType="textPersonName"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.497"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/Mob"
app:layout_constraintVertical_bias="0.103" />
<EditText
android:id="@+id/pass"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Pass"
android:inputType="textPersonName"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.497"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/user"
app:layout_constraintVertical_bias="0.144" />
<EditText
android:id="@+id/Lat"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Lat"
android:inputType="textPersonName"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.497"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/Long"
app:layout_constraintVertical_bias="0.075" />
<EditText
android:id="@+id/English"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="English"
android:inputType="textPersonName"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.497"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/Arabic"
app:layout_constraintVertical_bias="0.058" />
</androidx.constraintlayout.widget.ConstraintLayout>

这是在代码中调用我的图像视图的地方：

imageoffarm.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
askFileReadPermission();
}
});
}
private void askFileReadPermission() {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, READ_PERM_CODE);
} else {
Intent gallery = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(gallery, GALLERY_REQUEST_CODE);
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (requestCode == CAMERA_PERM_CODE || requestCode == READ_PERM_CODE || requestCode == WRITE_PERM_CODE) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Intent gallery = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(gallery, GALLERY_REQUEST_CODE);
}
} else {
Toast.makeText(this, "الرجاء قبول الكميرة لاجل التصوير", Toast.LENGTH_SHORT).show();
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);

if (requestCode == GALLERY_REQUEST_CODE) {
if (resultCode == Activity.RESULT_OK) {
Uri contentUri = data.getData();
File imageFile = new File(getRealPathFromURI(MainActivity.this, contentUri));
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_" + timeStamp + "." + getFileExt(contentUri);
DatabaseHelper databaseHelper = new DatabaseHelper(MainActivity.this);
databaseHelper.SavingimagepathAR(Uri.fromFile(imageFile).getPath());
Log.d("tag", "onActivityResult: Gallery Image Uri:  " + Uri.fromFile(imageFile));
imageoffarm.setImageURI(contentUri);

}
}
}

private String getRealPathFromURI(Context context, Uri contentUri) {
Cursor cursor = null;
try {
String[] proj = {MediaStore.Images.Media.DATA};
cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
} catch (Exception e) {
Log.e(TAG, "getRealPathFromURI Exception : " + e.toString());
return "";
} finally {
if (cursor != null) {
cursor.close();
}
}
}
private String getFileExt(Uri contentUri) {
ContentResolver c = getContentResolver();
MimeTypeMap mime = MimeTypeMap.getSingleton();
return mime.getExtensionFromMimeType(c.getType(contentUri));
}

有什么帮助吗！？

Answer 1

您使用了tools修饰符，它只显示Editor mode图像，并且会在屏幕上显示一个空的ImageView，但您仍然可以单击它。

更改后：

<ImageView
..
app:srcCompat="@drawable/galboy" />

Answer 2

使用 正在使用错误的命名空间。

在ImageView里面，用app:srcCompat代替tools:srcCompat