Question

我是android编程的初学者。我有一个应用程序将图像作为字节数组保存到sqlite db。在我的android工作室中没有检测到错误但是当我执行insert（通过按钮）时，应用程序崩溃。我从很多方面得到了很多方法。

图像来自相机并在ImageView中显示。

我正在使用Utility作为图像，DataHandler使用db。

知道我的代码有什么问题吗？请描述一下，因为我只是一个初学者:(

任何帮助对我来说都是一个很大的推动力。

这是我的代码

MyActivity.java

public class MyActivity extends Activity implements OnClickListener {

Button kirim;
EditText address, zipcode, otherID, stories, yearBuilt, screener, totalArea, buildingName, use;
DataHandler handler;

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

    bn = (Button) findViewById(R.id.bn);
    IMG = (ImageView) findViewById(R.id.img);
    bn.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent i = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            if(i.resolveActivity(getPackageManager())!=null){

                startActivityForResult(i, REQUEST_CODE);
            }
        }
    });

    kirim = (Button) findViewById(R.id.kirim);
    address = (EditText) findViewById(R.id.editAddress);
    zipcode = (EditText) findViewById(R.id.editZipCode);
    otherID = (EditText) findViewById(R.id.editOtherIdentifier);
    stories = (EditText) findViewById(R.id.editStories);
    yearBuilt = (EditText) findViewById(R.id.editYearBuilt);
    screener = (EditText) findViewById(R.id.editScreenerName);
    totalArea = (EditText) findViewById(R.id.editTotalFloorArea);
    buildingName = (EditText) findViewById(R.id.editBuildingName);
    use = (EditText) findViewById(R.id.editUsage);


    kirim.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View view) {
            String getAddress = address.getText().toString();
            String getZipcode = zipcode.getText().toString();
            String getOtherID = otherID.getText().toString();
            String getStories = stories.getText().toString();
            String getYear = yearBuilt.getText().toString();
            String getScreener = screener.getText().toString();
            String getTotalarea = totalArea.getText().toString();
            String getBuildingname = buildingName.getText().toString();
            String getUse = use.getText().toString();
            byte[] getImage = Utility.getBytes(BitmapFactory.decodeResource(getResources(), R.id.img));
            handler = new DataHandler(getBaseContext());
            handler.open();
            long id = handler.insertData(getAddress, getZipcode, getOtherID, getStories, getYear, getScreener, getTotalarea, getBuildingname, getUse, getImage);
            Toast.makeText(getBaseContext(), "Data Inserted", Toast.LENGTH_LONG).show();

        }
    });

Utility.java

public class Utility {
        // convert from bitmap to byte array
    public static byte[] getBytes(Bitmap bitmap) {
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.PNG, 0, stream);
        return stream.toByteArray();
    }

    // convert from byte array to bitmap
    public static Bitmap getPhoto(byte[] image) {
        return BitmapFactory.decodeByteArray(image, 0, image.length);
    }
}

DataHandler.java

public class DataHandler {
public static final String ADDRESS = "address";
public static final String ZIPCODE = "zipcode";
public static final String OTHERID = "otherID";
public static final String STORIES = "stories";
public static final String YEARBUILT = "yearBuilt";
public static final String SCREENER = "screener";
public static final String TOTALAREA = "totalArea";
public static final String BUILDINGNAME = "buildingName";
public static final String USAGE = "use";
public static final String IMAGE = "image";
public static final String TABLE_NAME = "mytable";
public static final String DATA_BASE_NAME = "mydb";
public static final int DATABASE_VERSION = 1;

DatabaseHelper dbhelper;
Context ctx;
SQLiteDatabase db;
public DataHandler(Context ctx){
    this.ctx = ctx;
    dbhelper = new DatabaseHelper(ctx);

}


private static class DatabaseHelper extends SQLiteOpenHelper{

    public DatabaseHelper(Context ctx){
        super(ctx,DATA_BASE_NAME, null, DATABASE_VERSION);

    }


    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {

            sqLiteDatabase.execSQL("CREATE TABLE " + TABLE_NAME + " (" + ADDRESS + " TEXT, " +
                    ZIPCODE + " TEXT NOT NULL, " +
                    OTHERID + " TEXT NOT NULL, " +
                    STORIES + " TEXT NOT NULL, " +
                    YEARBUILT + " TEXT, " +
                    IMAGE + " BLOB, " +
                    SCREENER + " TEXT, " +
                    TOTALAREA + " TEXT, " +
                    BUILDINGNAME + " TEXT, " +
                    USAGE + " TEXT, " +
                    IMAGE + " BLOB);"
            );




    }




    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i2) {

        sqLiteDatabase.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        onCreate(sqLiteDatabase);

    }
}
public DataHandler open(){
    dbhelper = new DatabaseHelper(ctx);
    db = dbhelper.getWritableDatabase();
    return this;
}

public void close(){
    dbhelper.close();
}

public long insertData(String address, String zipcode, String otherID, String stories, String yearBuilt, String screener, String totalArea, String buildingName, String use, byte[] image){

    ContentValues content = new ContentValues();
    content.put(ADDRESS, address);
    content.put(ZIPCODE, zipcode);
    content.put(OTHERID, otherID);
    content.put(STORIES, stories);
    content.put(YEARBUILT, yearBuilt);
    content.put(SCREENER, screener);
    content.put(TOTALAREA, totalArea);
    content.put(BUILDINGNAME, buildingName);
    content.put(USAGE, use);
    content.put(IMAGE, image);
    return db.insert(TABLE_NAME, null, content);
}}

这里是logcat显示错误

8289-8289 / com.example.brian.asprika E / OpenGLRenderer：SFEffectCache：clear（），mSize = 0 01-09 14：03：33.733 8289-8289 / com.example.brian.asprika W / IInputConnectionWrapper：showStatusIcon on inactive InputConnection 01-09 14：03：43.193 8289-8289 / com.example.brian.asprika I / HWUI：EGLImpl-HWUI受保护的EGL上下文已创建 01-09 14：03：46.593 8289-8289 / com.example.brian.asprika D / AndroidRuntime：关闭VM 01-09 14：03：46.593 8289-8289 / com.example.brian.asprika W / dalvikvm：threadid = 1：线程退出未捕获异常（组= 0x417a3c08） 01-09 14：03：46.603 8289-8289 / com.example.brian.asprika E / AndroidRuntime：FATAL EXCEPTION：main 处理：com.example.brian.asprika，PID：8289 显示java.lang.NullPointerException 在com.example.brian.asprika.Utility.getBytes（Utility.java:15）在com.example.brian.asprika.MyActivity $ 2.onClick（MyActivity.java:89）在android.view.View.performClick（View.java:4637）在android.view.View $ PerformClick.run（View.java:19422）在android.os.Handler.handleCallback（Handler.java:733）在android.os.Handler.dispatchMessage（Handler.java:95）在android.os.Looper.loop（Looper.java:136）在android.app.ActivityThread.main（ActivityThread.java:5586） at java.lang.reflect.Method.invokeNative（Native Method）在java.lang.reflect.Method.invoke（Method.java:515）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:1268）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:1084）在dalvik.system.NativeStart.main（本地方法）

Answer 1

byte[] getImage = Utility.getBytes(BitmapFactory.decodeResource(getResources(), R.id.img));

R.id.img不能是图片可绘制标识符，decodeResource()在此处返回null。

为资源中的图片使用R.drawable标识符。

保存图像到sqlite然后应用程序崩溃

1 个答案: