小编ant*_*lla的帖子

使用带有dao Pattern的ContentProvider是正确的.？或者它会带来任何性能问题？

我会尽力解释.我有一个contentProvider.一个活动,一个道和一个豆..

这是代码:

class Bean(){

 String name;

}

class Dao{

 Activity activity;

 public Dao(Activity activity){

 this.activity = activity;

public List<Bean> getAllBean() {

    Cursor c = activity.managedQuery(Bean.CONTENT_URI, PROJECTION,
                null, null, Bean.DEFAULT_SORT_ORDER);
    return BeanMapper.GetAllFromCursor(c);
    }
}

}

Class Activity{
.....


 onCreate(....){

  Dao dao = new Dao(this);
  List<Bean> aList = dao.getAllBean();

}
....}

你怎么看 ？

问候

在我的布局中,我只有八个单元格.
我希望单元格划分屏幕上的所有可用空间.这可能吗？

这是我的gridview布局:

<GridView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/dataGrid"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="10px"
    android:verticalSpacing="10px"
    android:horizontalSpacing="10px" 
    android:numColumns="2"
    android:gravity="fill" />

这是项目布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" 
    android:padding="6dip"  >   
  <TableRow
      android:layout_width="fill_parent"
      android:layout_height="fill_parent" >
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
      <TextView
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          android:textColor="#E00000"
          android:textStyle="bold"
          android:gravity="left"
          android:textSize="16dip"/>    
      <TextView
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          android:textColor="#000000"
          android:textStyle="normal"
          android:gravity="right"
          android:textSize="12dip"/>
    </LinearLayout>
  </TableRow>
</LinearLayout>

我尝试在我的自定义内容提供者上运行此查询.

cursor = activity.getContentResolver().query(
                GoalDescriptor.CONTENT_URI,
                "max(priority)", null,
                null, null);

获取优先级int列的最大值.

我也尝试过:

cursor = activity.getContentResolver().query(
                GoalDescriptor.CONTENT_URI,
                null, "max(priority)",
                null, null);

没有成功.

此代码返回此异常:

    java.lang.IllegalArgumentException: Invalid column MAX(priority)
E/DatabaseUtils(  688):     at android.database.sqlite.SQLiteQueryBuilder.computeProjection(SQLiteQueryBuilder.java:523)
E/DatabaseUtils(  688):     at android.database.sqlite.SQLiteQueryBuilder.buildQuery(SQLiteQueryBuilder.java:370)
E/DatabaseUtils(  688):     at android.database.sqlite.SQLiteQueryBuilder.query(SQLiteQueryBuilder.java:323)
E/DatabaseUtils(  688):     at android.database.sqlite.SQLiteQueryBuilder.query(SQLiteQueryBuilder.java:280)
E/DatabaseUtils(  688):     at nan.salsa.contentprovider.goal.GoalContentProvider.query(GoalContentProvider.java:118)
E/DatabaseUtils(  688):     at android.content.ContentProvider$Transport.bulkQuery(ContentProvider.java:150)
E/DatabaseUtils(  688):     at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:111)
E/DatabaseUtils(  688):     at android.os.Binder.execTransact(Binder.java:288)
E/DatabaseUtils(  688):     at dalvik.system.NativeStart.run(Native Method)
D/AndroidRuntime(  727): Shutting down VM

我的内容提供商实施(标准 - 请参阅notePad示例)

public Cursor query(Uri uri, String[] projection, String selection,
        String[] selectionArgs, …

我有自定义视图...

package nan.salsa.goal.customview;

import android.R;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.RectShape;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;

public class DayView extends View {

    private static String TAG="DayView";

    private ShapeDrawable mDrawable;

    public DayView(Context context) {
        super(context);
    }

    public DayView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public DayView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    public void init() {

        int x = 10;
        int y = 10;
        int width = 300;
        int height = …