【发布时间】：2020-04-11 09:06:48
【问题描述】：
我在 Android Studio 中的应用程序的另一个问题。我尝试在“SQLite”中添加数据，从我的观点来看，代码似乎是正确的，考虑到我刚开始编程 java。似乎出了点问题，没有显示“添加成功”的消息，并且 'setText=" "' 不起作用。
主java文件-“MainFragment”
package com.example.licenta23;
import android.Manifest;
import android.app.Activity;
import android.app.AppComponentFactory;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.Fragment;
import java.io.ByteArrayOutputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
public class MainFragment extends Fragment {
EditText actv1, edtModel, actv2, actv3, actv4, edtFabricatie, edtPret;
Button btnChoose, btnAdd, btnList;
ImageView imageView3;
final int REQUEST_CODE_GALLERY = 999;
public static SQLiteHelper sqLiteHelper;
private List<MarcaItem> marcaList;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_main, container, false);
init(view);
fillMarcaList();
AutoCompleteTextView editText = view.findViewById(R.id.actv1);
AutoCompleteMarcaAdapter adapter = new AutoCompleteMarcaAdapter(getActivity(), marcaList);
editText.setAdapter(adapter);
AutoCompleteTextView editText2 = view.findViewById(R.id.actv2);
ArrayAdapter<String> adapter2 = new ArrayAdapter<String>(getActivity(),
android.R.layout.simple_list_item_1, CAROSERIE);
editText2.setAdapter(adapter2);
AutoCompleteTextView editText3 = view.findViewById(R.id.actv3);
ArrayAdapter<String> adapter3 = new ArrayAdapter<String>(getActivity(),
android.R.layout.simple_list_item_1, COMBUSTIBIL);
editText3.setAdapter(adapter3);
AutoCompleteTextView editText4 = view.findViewById(R.id.actv4);
ArrayAdapter<String> adapter4 = new ArrayAdapter<String>(getActivity(),
android.R.layout.simple_list_item_1, CULOARE);
editText4.setAdapter(adapter4);
return view;
}
private void fillMarcaList() {
...
sqLiteHelper = new SQLiteHelper(getActivity(), "CarDB.sqlite", null, 1);
sqLiteHelper.queryData("CREATE TABLE IF NOT EXISTS CAR (Id INTEGER PRIMARY KEY AUTOINCREMENT, alegemarca VARCHAR, model VARCHAR, caroserie VARCHAR, combustibil VARCHAR, culoare VARCHAR, fabricatie VARCHAR, pret VARCHAR, image BLOG)");
btnChoose.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String[] permissions = new String[]{Manifest.permission.READ_EXTERNAL_STORAGE};
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M)
return;
for (String permission : permissions) {
if (ContextCompat.checkSelfPermission(getActivity(), permission) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(permissions, REQUEST_CODE_GALLERY); // triggers onRequestPermissionsResult() each time a permission is granted in 'permissions'
} else {
Toast.makeText(getActivity(), "Permission Already Granted", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(Intent.ACTION_PICK);
intent.setType("image/*");
startActivityForResult(intent, REQUEST_CODE_GALLERY);
}
}
}
});
btnAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
try{
sqLiteHelper.insertData(
actv1.getText().toString().trim(),
edtModel.getText().toString().trim(),
actv2.getText().toString().trim(),
actv3.getText().toString().trim(),
actv4.getText().toString().trim(),
edtFabricatie.getText().toString().trim(),
edtPret.getText().toString().trim(),
imageViewToByte(imageView3)
);
Toast.makeText(getActivity().getApplicationContext(), "Added successfully!", Toast.LENGTH_SHORT).show();
actv1.setText("");
edtModel.setText("");
actv2.setText("");
actv3.setText("");
actv4.setText("");
edtFabricatie.setText("");
edtPret.setText("");
imageView3.setImageResource(R.mipmap.ic_launcher);
}
catch (Exception e){
e.printStackTrace();
}
}
});
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] 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(getContext(), "You don't have permission to acces file location!", Toast.LENGTH_SHORT).show();
}
return;
}
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
@Override
public void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
if(requestCode == REQUEST_CODE_GALLERY && resultCode == Activity.RESULT_OK && data != null) {
Uri uri = data.getData();
try {
InputStream inputStream = getActivity().getContentResolver().openInputStream(uri);
Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
imageView3.setImageBitmap(bitmap);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
}
super.onActivityResult(requestCode, resultCode, data);
}
private void init(View view){
actv1 = (EditText) view.findViewById(R.id.actv1);
edtModel = (EditText) view.findViewById(R.id.edtModel);
actv2 = (EditText) view.findViewById(R.id.actv2);
actv3 = (EditText) view.findViewById(R.id.actv3);
actv4 = (EditText) view.findViewById(R.id.actv4);
edtFabricatie = (EditText) view.findViewById(R.id.edtFabricatie);
edtPret = (EditText) view.findViewById(R.id.edtPret);
btnChoose = (Button) view.findViewById(R.id.btnChoose);
btnAdd = (Button) view.findViewById(R.id.btnAdd);
btnList = (Button) view.findViewById(R.id.btnList);
imageView3 = (ImageView) view.findViewById(R.id.imageView3);
}
public static byte[] imageViewToByte(ImageView image) {
Bitmap bitmap = ((BitmapDrawable) image.getDrawable()).getBitmap();
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();
return byteArray;
}
}
SQLiteHelper：
package com.example.licenta23;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteStatement;
import androidx.annotation.Nullable;
public class SQLiteHelper extends SQLiteOpenHelper {
public SQLiteHelper(@Nullable Context context, @Nullable String name, @Nullable 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 alegemarca, String model, String caroserie, String combustibil, String culoare, String fabricatie, String pret, byte[] image) {
SQLiteDatabase database = getWritableDatabase();
String sql = "INSERT INTO CAR VALUES (NULL, ?, ?, ?, ?, ?, ?, ?)";
SQLiteStatement statement = database.compileStatement(sql);
statement.clearBindings();
statement.bindString(1, alegemarca);
statement.bindString(2, model);
statement.bindString(3, caroserie);
statement.bindString(4, combustibil);
statement.bindString(5, culoare);
statement.bindString(6, fabricatie);
statement.bindString(7, pret);
statement.bindBlob(8, image);
statement.executeInsert();
}
public Cursor getData(String sql){
SQLiteDatabase database = getReadableDatabase();
return database.rawQuery(sql, null);
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
谢谢！
【问题讨论】：
-
在您的 logcat 中查找可能来自您在添加
onClick()中的catch的堆栈跟踪。我要指出的是，您尝试绑定的参数比INSERT语句中的占位符?s 多，所以这是一个问题，但我们需要该堆栈跟踪才能确定它是否是当前的。
标签： java android android-studio android-fragments android-sqlite