如何从android SQLite数据库中检索图库的随机图片，并将其显示在名称和价格的另一个Activity中？当我点击“个人资料”按钮时，我的应用程序崩溃，但数据已成功添加。
我的代码是：
MainActivity类：
public class MainActivity extends AppCompatActivity {
EditText edtName, edtPrice;
Button btnChoose, btnAdd, btnList;
ImageView imageView;
Uri imageuri;
final int REQUEST_CODE_GALLERY = 999;
private static final int pick_image = 100;
public static SQLiteHelper sqLiteHelper;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
edtName = (EditText) findViewById(R.id.edtName);
edtPrice = (EditText) findViewById(R.id.edtPrice);
btnChoose = (Button) findViewById(R.id.btnChoose);
btnAdd = (Button) findViewById(R.id.btnAdd);
btnList = (Button) findViewById(R.id.btnList);
imageView = (ImageView) findViewById(R.id.imageView);
sqLiteHelper = new SQLiteHelper(this, "FoodDB.sqlite", null, 1);
sqLiteHelper.queryData("CREATE TABLE IF NOT EXISTS FOOD(Id INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR, price VARCHAR, image BLOB)");
btnChoose.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent gallery = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.INTERNAL_CONTENT_URI);
startActivityForResult(gallery,pick_image);
}
});
btnAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
try{
sqLiteHelper.insertData(
edtName.getText().toString().trim(),
edtPrice.getText().toString().trim(),
imageViewToByte(imageView)
);
Toast.makeText(getApplicationContext(), "Added successfully!", Toast.LENGTH_SHORT).show();
// edtName.setText("");
//edtPrice.setText("");
// imageView.setImageResource(R.mipmap.ic_launcher);
String s = "iqra"; //why we take string whrn we take only next button,is it necessary to take the string?
Intent i = new Intent(MainActivity.this, foodprofile.class);
Bundle bun = new Bundle();
bun.putString("name", s);
i.putExtras(bun);
startActivity(i);
}
catch (Exception e){
e.printStackTrace();
}
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(resultCode == RESULT_OK && requestCode == pick_image){
imageuri = data.getData();
imageView.setImageURI(imageuri);
}
}
public static byte[] imageViewToByte(ImageView image) {
Bitmap bitmap = ((BitmapDrawable)image.getDrawable()).getBitmap();
ByteArrayOutputStream stream = new ByteArrayOutputStream();
//bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
bitmap.compress(Bitmap.CompressFormat.JPEG, 0, stream);
byte[] byteArray = stream.toByteArray();
return byteArray;
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if(requestCode == REQUEST_CODE_GALLERY){
if(grantResults.length >0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
Intent intent = new Intent(Intent.ACTION_PICK);
intent.setType("image/*");
startActivityForResult(intent, REQUEST_CODE_GALLERY);
}
else {
Toast.makeText(getApplicationContext(), "You don't have permission to access file location!", Toast.LENGTH_SHORT).show();
}
return;
}
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
SQLitehelper类：
public class SQLiteHelper extends SQLiteOpenHelper {
public SQLiteHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
super(context, name, factory, version);
}
public void queryData(String sql){
SQLiteDatabase database = getWritableDatabase();
database.execSQL(sql);
}
public void insertData(String name, String price, byte[] image){
SQLiteDatabase database = getWritableDatabase();
String sql = "INSERT INTO FOOD VALUES (NULL, ?, ?, ?)";
SQLiteStatement statement = database.compileStatement(sql);
statement.clearBindings();
statement.bindString(1, name);
statement.bindString(2, price);
statement.bindBlob(3, image);
statement.executeInsert();
}
public void updateData(String name, String price, byte[] image, int id) {
SQLiteDatabase database = getWritableDatabase();
String sql = "UPDATE FOOD SET name = ?, price = ?, image = ? WHERE id = ?";
SQLiteStatement statement = database.compileStatement(sql);
statement.bindString(1, name);
statement.bindString(2, price);
statement.bindBlob(3, image);
statement.bindDouble(4, (double)id);
statement.execute();
database.close();
}
public void deleteData(int id) {
SQLiteDatabase database = getWritableDatabase();
String sql = "DELETE FROM FOOD WHERE id = ?";
SQLiteStatement statement = database.compileStatement(sql);
statement.clearBindings();
statement.bindDouble(1, (double)id);
statement.execute();
database.close();
}
public Cursor getData(){
SQLiteDatabase db = this.getWritableDatabase();
Cursor res = db.rawQuery("Select * from food ",null);
return res;
}
@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
}
@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
}
}
foodprofile
public class foodprofile extends AppCompatActivity {
SQLiteHelper sqLiteHelper;
Button profile;
TextView txtresult1,txtresult2,txtresult6;
ImageView imgvresult;
Uri imageuri;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_foodprofile);
txtresult1 = (TextView) findViewById(R.id.name);
txtresult2 = (TextView) findViewById(R.id.price);
imgvresult = (ImageView) findViewById(R.id.image) ;
profile = (Button) findViewById(R.id.btnprofile);
}
public void profile(View v) {
if(v.getId()==R.id.btnprofile) {
Cursor res = sqLiteHelper.getData();
StringBuffer stringbuffer = new StringBuffer();
Toast pass = Toast.makeText(foodprofile.this,"inserted successfully", Toast.LENGTH_SHORT);
pass.show();
txtresult1.setText(" " + res.getString(0) );
txtresult2.setText(" " + res.getString(1) );
imgvresult.setImageURI(imageuri);
// imgvresult.setImageResource(res.getString(2),R.mipmap.ic_launcher);
//imgvresult.setImageResource(res.getBlob(0x2));
txtresult6.setText("-------------------------" + "\n");
//txtresult.setText(stringbuffer.toString());
Toast pass1= Toast.makeText(foodprofile.this, "retrieve successfully", Toast.LENGTH_SHORT);
pass1.show();
}
}
}
foodprofile.xml：
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#ffffff" >
<Button
android:id="@+id/btnprofile"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="profile"
android:background="@color/colorPrimaryDark"
android:onClick="profile"/>
<ImageView
android:id="@+id/image"
android:layout_marginTop="55dp"
android:layout_width="match_parent"
android:layout_height="200dp" />
<TextView
android:id="@+id/name"
android:textColor="#000"
android:textStyle="bold"
android:textSize="30dp"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:layout_marginTop="300dp"/>
<TextView
android:id="@+id/price"
android:textColor="#000"
android:textStyle="bold"
android:textSize="30dp"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:layout_marginTop="350dp"/>
</RelativeLayout>
</ScrollView>
答案 0 :(得分：0)
你需要： -
以下内容： -
public void profile(View v) {
if(v.getId()==R.id.btnprofile) {
Cursor res = sqLiteHelper.getData();
StringBuffer stringbuffer = new StringBuffer();
Toast pass = Toast.makeText(foodprofile.this,"inserted successfully", Toast.LENGTH_SHORT);
pass.show();
txtresult1.setText(" " + res.getString(0) );
txtresult2.setText(" " + res.getString(1) );
// get the Blob
byte[] my_bytearray = res.getBlob(2);
// convert byte array into a bitmap
Bitmap bmp = BitmapFactory.decodeByteArray(my_bytearray, 0, my_bytearray.length);
// apply the image to the image view
imgvresult.setImageBitmap(Bitmap.createScaledBitmap(bmp, image.getWidth(),
image.getHeight(), false)));
Toast pass1= Toast.makeText(foodprofile.this, "retrieve successfully", Toast.LENGTH_SHORT);
pass1.show();
}
}