我無法在圖像視圖中加載存儲在SQLite數據庫中的圖像

Question

我已將BLOB中的圖像存儲在數據庫中，但我無法在佈局中加載它，請幫我解決問題。

應用程序在運行過程中被關閉（不幸的是圖像已停止）。

MainActivity.java

package com.example.image; 

import android.app.Activity; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.os.Bundle; 
import android.view.Menu; 
import android.widget.ImageView; 

public class MainActivity extends Activity { 
SQLiteDatabase myDB; 
String TableName = "employee_details"; 
String Data = ""; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    myDB = this.openOrCreateDatabase("hello", MODE_PRIVATE, null); 

    Cursor c = myDB.rawQuery("SELECT image FROM employee_details WHERE name= 'john'", null); 

    byte[] blob = c.getBlob(c.getColumnIndex("image")); 


    Bitmap theImage = BitmapFactory.decodeByteArray(blob, 0, blob.length); 


      ((ImageView)findViewById(R.id.item_icon)).setImageBitmap(theImage); 




} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
} 

} 

activity_main

<ImageView 
    android:id="@+id/item_icon" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentLeft="true" 
    android:layout_alignParentTop="true" 
    android:adjustViewBounds="true" 
    android:maxHeight="80dp" 
    android:maxWidth="80dp" 
    /> 

我用於插入到數據庫

Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.icon); 

    ByteArrayOutputStream bos = new ByteArrayOutputStream(); 

    bitmap.compress(CompressFormat.PNG, 100 /*ignored for PNG*/, bos); 

    byte[] bitmapdata = bos.toByteArray(); 

    myDB = this.openOrCreateDatabase("hello", MODE_PRIVATE, null); 

    myDB.execSQL("INSERT INTO " + TableName + " (name,image)" + " VALUES ('" 
       + "john" + "','"+ bitmapdata + "');"); 

logcat的代碼

08-01 09:12:57.375: E/Trace(28173): error opening trace file: No such file or directory (2) 
08-01 09:12:58.816: D/AndroidRuntime(28173): Shutting down VM 
08-01 09:12:58.816: W/dalvikvm(28173): threadid=1: thread exiting with uncaught exception (group=0x40a71930) 
08-01 09:12:58.825: E/AndroidRuntime(28173): FATAL EXCEPTION: main 
08-01 09:12:58.825: E/AndroidRuntime(28173): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.image/com.example.image.MainActivity}: android.database.CursorIndexOutOfBoundsException: Index -1 requested, with a size of 1 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.app.ActivityThread.access$600(ActivityThread.java:141) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.os.Handler.dispatchMessage(Handler.java:99) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.os.Looper.loop(Looper.java:137) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.app.ActivityThread.main(ActivityThread.java:5041) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at java.lang.reflect.Method.invokeNative(Native Method) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at java.lang.reflect.Method.invoke(Method.java:511) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at dalvik.system.NativeStart.main(Native Method) 
08-01 09:12:58.825: E/AndroidRuntime(28173): Caused by: android.database.CursorIndexOutOfBoundsException: Index -1 requested, with a size of 1 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.database.AbstractCursor.checkPosition(AbstractCursor.java:424) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:136) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.database.AbstractWindowedCursor.getBlob(AbstractWindowedCursor.java:44) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at com.example.image.MainActivity.onCreate(MainActivity.java:32) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.app.Activity.performCreate(Activity.java:5104) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080) 
08-01 09:12:58.825: E/AndroidRuntime(28173): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144) 
08-01 09:12:58.825: E/AndroidRuntime(28173): ... 11 more 

有人可以發佈我從數據庫插入和檢索圖像的代碼？如果您可以使用Java和XML發佈整個代碼將會很有幫助。

Answer 1

試圖改變這一點：

ImageView imgdisplay;; 

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

    imgdisplay = (ImageView) findViewById(R.id.item_icon); 
    myDB = this.openOrCreateDatabase("hello", MODE_PRIVATE, null); 

    Cursor c = myDB.rawQuery("SELECT image FROM employee_details WHERE name= 'john'", null); 

    if (c.getCount() > 0) { 
     c.moveToFirst(); 
     do { 

      byte[] blob = c.getBlob(c.getColumnIndex("image")) 
      Bitmap b = BitmapFactory.decodeByteArray(blob , 0, blob .length); 
      imgdisplay.setImageBitmap(b); 

     } while (c.moveToNext()); 

    } 
    c.close(); 

//close yourdatabase here } 

的調整你的位圖對象：

public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) { 
    int width = bm.getWidth(); 
    int height = bm.getHeight(); 
    float scaleWidth = ((float) newWidth)/width; 
    float scaleHeight = ((float) newHeight)/height; 
// CREATE A MATRIX FOR THE MANIPULATION 
    Matrix matrix = new Matrix(); 
// RESIZE THE BIT MAP 
    matrix.postScale(scaleWidth, scaleHeight); 

// "RECREATE" THE NEW BITMAP 
    Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, 
     matrix, false); 
    return resizedBitmap;}