Android应用 - 我该如何更新我的列表项？ [英] Android app - how do I update my ListItem?
问题描述
有关Android应用程序......我有一个调用自定义ListActivity的活动按钮。这ListActivity具有文本和一个复选框的两行。调用时，ListActivity开辟了一个XML文件中的设备上（那个local.xml ）。此XML文件中包含的网页上目标XML文件的列表。如果该文件在设备上存在，就ListActivity的复选框被选中，否则就不是。
For an Android app...I have a button on an Activity that calls a custom ListActivity. This ListActivity has two lines of text and a checkbox. When invoked, the ListActivity opens up an XML file on the device (local.xml) . This XML file contains a list of target XML files on the web. If the file exists on the device, the checkbox on the ListActivity is checked, otherwise it isn't.
在该列表项为pressed，它会检查如果目标文件上存在设备，如果是的话，它会显示一个对话框，询问是否要覆盖。如果该文件不存在，或者如果他们选择了覆盖，是因为它进入到互联网，并抓住一组文件（目标XML文件包含JPEG文件的列表，收集）。
When the ListItem is pressed, it checks to see if the target file exists on the device-if it does, it displays a dialog box asking if they want to overwrite. If the file doesn't exist, or if they chose to overwrite, a progress dialog is displayed as it goes to the internet and grabs a set of files (the target XML file contains a list of JPegs to gather).
下载JPEG文件后，我改变对正在进行的消息来显示所有的JPEG文件是否下载与否。它睡了几秒钟，然后在前看不见。
After downloading the JPegs, I change the message on the progress to show whether all the JPegs downloaded or not. It sleeps for a few seconds, then disapears.
所有上述作品。
我的问题是：
-
完成后，如何设置与pressed项目相关的复选框，根据是否所有下载的JPEG文件或不？
After completion, how do I set the checkbox associated with the pressed item, based on whether all of the JPegs downloaded or not?
我真的想一个三态的指标，而不是一个复选框，这是二进制的，除非我可以改变颜色为黄色。有没有更好的部件，我应该使用吗？
I'd really like a tri-state indicator instead of a checkbox, which is binary, unless I could change the color to yellow. Is there a better widget I should be using here?
Relvant code如下（让我知道如果你需要查看更多）
Relvant code follows (let me know if you need to see more)
最初的活动：
public class RRS_Preferences extends Activity {
onCreate(yadda, yadda) {
}
public void Button_Listener(View view) {
/* open up the ListView Activity */
Intent myIntent = new Intent();
myIntent.setClassName("com.sinisterlabs.mypackage", "com.sinisterlabs.mypackage.Download_List");
startActivity(myIntent);
}
}
自定义列表活动：
Custom List Activity:
public class Download_List extends ListActivity {
List<Location>loc_list = new ArrayList<Location>();
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setListAdapter(new RRSList_ArrayAdapter(this));
selection = (TextView)findViewById(R.id.tableRow1);
/* Open the "local.xml" file, pull from it the list of files that need to go
onto the ListActivity. For each file, I add it to the List. */
loc_list.add(new Location(stringLocalFilename, stringURL, booleanIsPresent));
}
protected void onListItemClick(final ListView parent, final View v, int position, long href) {
if (fileLocalFile.exists) {
subDownloadJPegs(fileLocalFile);
} else { // Ask to download or not?
AlertDialog.Builder alertBuilder = new AlertDialog.Builder(this);
alertBuilder.setMessage("Are you sure you want to OverWrite this file and all of its image files?")
.setCancelable(false)
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
subDownloadJPegs(fileLocalFile);
}
});
.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
Toast.makeText(getApplicationContext(), "OverWrite Operation Cancelled...", Toast.LENGTH_LONG).show();
}
});
AlertDialog alert = alertBuilder.create();
alert.show();
}
}
private void subDownloadJPegs(fileLocalFile) {
progDialog = new ProgressDialog(this);
progDialog.setCancelable(true);
progDialog.setMessage("Downloading files for " + fileLocalFile.toString() + "...");
progDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
progDialog.setProgress(0);
/* open up this file and count the number of JPegs to be downloaded */
progDialog.setMax(intMax);
progDialog.setMessage("Downloading Sign Files for " + RuleSetName + "...");
progDialog.show();
/* background thread to update progress bar */
Thread background = new Thread (new Runnable() {
@Overide
public void run() {
/* Inside a loop, download each file, increment the progress bar as we do */
progressHandler.sendMessage(progressHandler.obtainMessage());
}
background.start();
}
Handler progressHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
progDialog.incrementProgressBy(1);
}
}
列表项布局XML：
List Item Layout XML:
<?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="wrap_content"
android:orientation="horizontal" >
<CheckBox
android:id="@+id/checkBox1"
android:layout_width="50dp"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:clickable="false"
android:focusable="false"
android:gravity="center" />
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView android:id="@+id/text1"
android:layout_width="fill_parent"
android:layout_height="20dp"
android:textSize="18dp"></TextView>
<TextView android:id="@+id/text2"
android:layout_width="fill_parent"
android:layout_height="15dp"
android:textSize="13dp"></TextView>
</LinearLayout>
</LinearLayout>
谢谢！
推荐答案
OK，我知道了。问题是，我打的电话，以关闭该对话框。它结束了一个catch语句内，从来没有执行。在修复此，我也我的参数调用处理程序，这让事情更清晰。
OK, I got it. the problem was where I placed the call to dismiss the dialog box. It ended up inside a catch statement and was never executing. In fixing this, I also parameterized my calls to the handler, which made things clearer.
Wheh！
： - ）
Wheh! :-)
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