Java 对话框未从其他类显示
可能重复:Java 对话框未从其他类显示,java,android,json,progressdialog,Java,Android,Json,Progressdialog,可能重复: 我在主课上打电话 新建自动更新()。checkForUpdate(此) 这就是行动 public void checkForUpdate(Context context) { // check when last checked. unless overridden check once a day. // get current version int resID = context.getResources().getIdent
我在主课上打电话 新建自动更新()。checkForUpdate(此) 这就是行动
public void checkForUpdate(Context context) {
// check when last checked. unless overridden check once a day.
// get current version
int resID = context.getResources().getIdentifier("current_version",
"string", context.getPackageName());
currentVersion = context.getResources().getString(resID);
// check for connection
// now compare versions
if (currentVersion.equals(serverVersion) == false) {
ProgressDialog pDialog = new ProgressDialog(context);
pDialog.setMessage("DO NOT ROTATE YOUR DEVICE. /nI am upgrading your version, press OK then INSTALL in a minute. Please wait....");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
try {
URL url = new URL(prefs.getString("server_address", null)
+ "/updates/eduDroid.apk");
HttpURLConnection c = (HttpURLConnection) url.openConnection();
String PATH = Environment.getExternalStorageDirectory()
+ "/download/";
File file = new File(PATH);
file.mkdirs();
File outputFile = new File(file, "eduDroid.apk");
FileOutputStream fos = new FileOutputStream(outputFile);
InputStream is = c.getInputStream();
byte[] buffer = new byte[1024];
int len1 = 0;
while ((len1 = is.read(buffer)) != -1) {
fos.write(buffer, 0, len1);
}
fos.close();
is.close();
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(new File(Environment
.getExternalStorageDirectory()
+ "/download/"
+ "file.apk")),
"application/vnd.android.package-archive");
context.startActivity(intent);
} catch (IOException e) {
Toast.makeText(context, "Update error!", Toast.LENGTH_LONG)
.show();
}
pDialog.dismiss();
}
}
问题是下载更新版本需要很长时间。在这段时间内,用户将被留下一个空白屏幕。我想给他们看这个对话框,但它就是不显示。请提供帮助您可以使用
异步任务
在后台处理网络事务:
if (currentVersion.equals(serverVersion) == false) {
new AsyncTask<Void, Void, Void>() {
private ProgressDialog pDialog;
@Override
protected void onPreExecute() {
pDialog = new ProgressDialog(context);
pDialog.setMessage("DO NOT ROTATE YOUR DEVICE. /nI am upgrading your version, press OK then INSTALL in a minute. Please wait....");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
try {
URL url = new URL(prefs.getString("server_address",
null) + "/updates/eduDroid.apk");
HttpURLConnection c = (HttpURLConnection) url
.openConnection();
String PATH = Environment.getExternalStorageDirectory()
+ "/download/";
File file = new File(PATH);
file.mkdirs();
File outputFile = new File(file, "eduDroid.apk");
FileOutputStream fos = new FileOutputStream(outputFile);
InputStream is = c.getInputStream();
byte[] buffer = new byte[1024];
int len1 = 0;
while ((len1 = is.read(buffer)) != -1) {
fos.write(buffer, 0, len1);
}
fos.close();
is.close();
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(new File(Environment
.getExternalStorageDirectory()
+ "/download/"
+ "file.apk")),
"application/vnd.android.package-archive");
context.startActivity(intent);
} catch (IOException e) {
Toast.makeText(context, "Update error!",
Toast.LENGTH_LONG).show();
}
}
@Override
protected void onPostExecute(Void result) {
pDialog.dismiss();
}
}.execute();
}
if(currentVersion.equals(serverVersion)==false){
新建异步任务(){
私人对话;
@凌驾
受保护的void onPreExecute(){
pDialog=新建进度对话框(上下文);
pDialog.setMessage(“请勿旋转您的设备。/n我正在升级您的版本,请按“确定”,然后在一分钟内安装。请稍候…”);
pDialog.setUndeterminate(假);
pDialog.setCancelable(真);
pDialog.show();
}
@凌驾
受保护的Void doInBackground(Void…参数){
试一试{
URL URL=新URL(prefs.getString(“服务器地址”),
null)+“/updates/eduDroid.apk”);
HttpURLConnection c=(HttpURLConnection)url
.openConnection();
String PATH=Environment.getExternalStorageDirectory()
+“/下载/”;
文件=新文件(路径);
mkdirs()文件;
File outputFile=新文件(文件“eduDroid.apk”);
FileOutputStream fos=新的FileOutputStream(outputFile);
InputStream=c.getInputStream();
字节[]缓冲区=新字节[1024];
int len1=0;
而((len1=is.read(buffer))!=-1){
fos.写入(缓冲区,0,len1);
}
fos.close();
is.close();
意向意向=新意向(意向.行动\视图);
intent.setDataAndType(Uri.fromFile)(新文件(环境
.getExternalStorageDirectory()
+“/下载/”
+“file.apk”),
“application/vnd.android.package归档文件”);
背景。开始触觉(意图);
}捕获(IOE异常){
Toast.makeText(上下文,“更新错误!”,
Toast.LENGTH_LONG).show();
}
}
@凌驾
受保护的void onPostExecute(void结果){
pDialog.disclose();
}
}.execute();
}
在向对话框传递上下文时,尝试使用handler或Runnable显示进度对话框和(ActivityName.this)而不是(this)。wtf是否获取剩余值?为什么不使用getString(R.string.current_版本)?使用asynctask或activity.showDialog()。您正试图在ui线程外显示一个对话框,它是forbidden@njzk2谢谢你指出这一点!这是一个名称的变化,但现在改变了。谢谢,这似乎已经奏效。