Java 使用AsyncTask获取图像的缩略图
我正在使用ListView显示数据库中的行。我在我的行中显示全分辨率图像,这导致我的手机延迟。如何显示缩略图Java 使用AsyncTask获取图像的缩略图,java,android,android-asynctask,imageview,Java,Android,Android Asynctask,Imageview,我正在使用ListView显示数据库中的行。我在我的行中显示全分辨率图像,这导致我的手机延迟。如何显示缩略图 public void getListFromDb(){ Cursor res = myDb.ViewAll(); startManagingCursor(res); //Map cursor from db to viewFields String[] fromFieldNames = new String[]{DatabaseHelper.COL_
public void getListFromDb(){
Cursor res = myDb.ViewAll();
startManagingCursor(res);
//Map cursor from db to viewFields
String[] fromFieldNames = new String[]{DatabaseHelper.COL_2, DatabaseHelper.COL_3, DatabaseHelper.COL_4, DatabaseHelper.COL_5, DatabaseHelper.COL_6};
int[] toViewIDS = new int[]{R.id.viewName, R.id.viewAddress, R.id.viewPostcode, R.id.viewType, R.id.imageView};
//Create SimpleCursorAdaptor with null cursor
SimpleCursorAdapter myCursorAdaptor = new SimpleCursorAdapter(this, R.layout.item_layout, null, fromFieldNames, toViewIDS, 0);
// Set adaptor for listView
myList.setAdapter(myCursorAdaptor);
new AsyncTask<SimpleCursorAdapter, Void, Cursor>() {
private SimpleCursorAdapter mSimpleCursorAdapter;
@Override
protected Cursor doInBackground(SimpleCursorAdapter... params) {
// Save cursorAdapter to use in postExecute
this.mSimpleCursorAdapter = params[0];
// Load cursor on background thread with search function
return myDb.ViewAll();
}
}
public void getListFromDb(){
Cursor res=myDb.ViewAll();
开始管理光标(res);
//将光标从db映射到viewFields
String[]fromFieldNames=新字符串[]{DatabaseHelper.COL_2,DatabaseHelper.COL_3,DatabaseHelper.COL_4,DatabaseHelper.COL_5,DatabaseHelper.COL_6};
int[]toViewIDS=newint[]{R.id.viewName,R.id.viewAddress,R.id.viewPostcode,R.id.viewType,R.id.imageView};
//使用空光标创建SimpleCursorAdaptor
SimpleCursorAdapter MyCursorAdapter=新的SimpleCursorAdapter(this,R.layout.item_layout,null,fromFieldNames,toViewId,0);
//设置listView的适配器
设置适配器(myCursorAdaptor);
新建异步任务(){
私有SimpleCursorAdapter mSimpleCursorAdapter;
@凌驾
受保护的游标doInBackground(SimpleCursorAdapter…参数){
//保存游标适配器以在postExecute中使用
this.mSimpleCursorAdapter=params[0];
//使用搜索功能将光标加载到背景线程上
返回myDb.ViewAll();
}
}
我正在从数据库中检索图像的实际路径
干杯阅读谷歌的文档,其中包含示例代码,允许您将图像缩小到所需的大小