c# - WPF Event: BitmapImage PropertyChanged: "Calling Thread Cannot access" -


I am trying to understand what the following code is about which is loading < / B> Displaying a text file and its contents, but is not happy with loading the betamap image and appearing on the timer. Alleased Event Handler

I understand that it has to do with the UI Thread.

But why is this not a problem for textfile example?

First of all, XAML: 

  & lt; Window x: orbit = "wpfApplication7 .indow1" xmlns = "http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns: x = "http://schemas.microsoft.com/winfx/ 2006 / xaml "title =" window 1 "height =" 300 "width =" 300 "& gt; & Lt; StackPanel Orientation = "Vertical" & gt; & Lt; TextBlock Text = "{Binding Path = Message, Update Instructor = Property Changes}" fontSize = "20" height = "40" width = "300" background = "ALSWB" /> & Lt; Image source = "{binding path = image, update sourcerame = property changed]" height = "100" width = "100" /> & Lt; / StackPanel & gt; & Lt; / Window & gt;

and C #, which raises an estate changelog handler on a timer: 

  using the system; Using System.ComponentModel; Using System.Timers; Using System.Windows; Using System.IO; Using System.Windows.Threading; System.Windows.Media Using imaging;

and 

  namespace WpfApplication7 {public partial squares window 1: window, INotifyPropertyChanged {public BitmapImage Image {get; Private set; } Public string message {get; Set; } Public Event PropertyChangedEventHandler PropertyChanged = delegate {}; Private Timer Timer; Public Window 1 () {InitializeComponent (); this. DataContext = This; This.timer = New timer {enabled = true, interval = 100}; This.timer.Elapsed + = (S, E) = & gt; {// --- Loading happy with text file UI updates :) this.Message = File.ReadAllText (@ "c: \ windows \ win.ini") Substrings (0, 20); Property changed (this, new asset changed event event ("message")); // --- No bitmap imaging loading. The property is unhappy :( // (I do not have to !! !!) // Application.Dispatcher.InvoC (// Dispatcher advance, assigned new action (rep // // this.Image = new bitmapImage (new Uri (@ "C: \ windows web \ wallpaper \ upcent.jpg"); // Edit - EhHah, Thanks Daniel! // Dependency Object-> FreeJoyel-> Animable-> ImageSource-> Bitmap Source - & Gt; Bitmap import this image, image.fridge ();

I know I can fix it with an "application. Current dispatcher. Invoke". Therefore fixing is not a problem. I do not understand why I have a problem :)

same question

    • I think important between two scenarios The difference is that the bitmap image is a dependency object, which means that it contains the "owner" thread (the thread created for the object). When your main UI thread tries to use the built-in bitmapmage object (and proprietary) on another thread ... Boom!

    Strings, on the other hand, are not a concept of "owner" threads.


    Comments

    Post a Comment

    Popular posts from this blog

    python - Overriding the save method in Django ModelForm -

    I'm having trouble overriding a ModelForm save method. I get this error I'm: Exception type: TypeErier Exception Value: Save () found an unexpected keyword argument 'committed' My intentions include a form 3 fields Submit several values ​​for, then create an object for each combination of those areas, and to save each object file models.py class collarsult type (models.Model): id = model. AutoField (db_column = 'icontact_result_code_type_id', primary_key = true) callResult = models.ForeignKey ( 'CallResult', db_column = 'icontact_result_code_id') campaign = models.ForeignKey ( 'campaign', db_column = 'icampaign_id') CALLTYPE = models.ForeignKey ( 'CALLTYPE', db_column = 'icall_type_id') agent = models.BooleanField (db_column = 'bagent', default = true) teamLeader = models.BooleanField (db_column = 'bTeamLeader', default = true) active = models.BooleanField (db_column = Django.form...
    Read more

    html - CSS autoheight, but fit content to height of div -

    I have a div in which there are three children- div in the left and middle div: float: left while true: float: true because it is my layout Actually will spoil, I've used ClearFix Hack: .cf {zoom: 1; }. Cf: First,. Cf: {content: ""; Display: Table; }. Cf: After {clear: both; } It still works, but I want to be the right div an indicator. So it should fill 100% of the parent unit of height. How can I complete this? PS is the full code: & Lt; / Div & gt; & Lt; Div class = "mobile_content" & gt; & Lt; H5 & gt; {{Data.titel}} & lt; / H5> & Lt; Table & gt; & Lt; TR & gt; & Lt; Th & gt; Komponist: & lt; / Th & gt; & Lt; TD & gt; {{Data.komponist}} & lt; / TD & gt; & Lt; / TR & gt; & Lt; TR & gt; & Lt; Th & gt; Instrument: & lt; / Th & gt; & Lt; TD & gt; {{Data.instrumente}} & lt; / TD & gt; & Lt; / TR & gt;...
    Read more

    qt - How to prevent QAudioInput from automatically boosting the master volume to 100%? -

    I have been trying to use Qt5 multimedia to record audio with QAudioInput, however, when I see If QAudioInput is started, it increases the master volume of my sound device to 100%. How can I prevent QAudioInput from changing the master volume? My current development platform is Linux with PalsAdio (with flat audio disabled). How can I use QAudioInput : QAudioDeviceInfo device_info = QAudioDeviceInfo :: defaultInputDevice (); QAudio format format; Format.setSampleRate (44100); Format.setChannelCount (1); Format.setSampleSize (16); Format.setCodec ("Audio / PCM"); Format.setSampleType (QAudioFormat :: SignedInt); Format.setByteOrder (QAudioFormat :: LittleEndian); Std :: cout & lt; & Lt; Device_info.deviceName (). ToUtf8 (). ConstData () & lt; & Lt; Std :: endl; QAudioInput * default_device = new QAudioInput (device_info, format); QIODevice * default_io_device = default_device-> Start (); a QAudioInput.setVolume () method is not you I ...
    Read more