Xamarin forms page doesn't load until async call is done
0
I'm trying to open a new page which shows a list that is populated with data from the server. The call to get the data from the server is done using an async function that is called from OnAppearing method. However, even though the method is async, my UI page is not shown until the call is done. How can I fix that or what is the best practice to make this call?
This is my XAML code for the page:
<StackLayout>
<Label
x:Name="NoPostsMessage"
Text="You have not created any posts yet :("
VerticalOptions="CenterAndExpand"
HorizontalOptions="CenterAndExpand" />
<ListView
x:Name="PostList"
SelectionMode="None">
<ListView.ItemTemplate>
<DataTemplate>
<TextCell Text="{Binding Text}" Detail="{Binding Detail}" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
This is my C# code:
protected override void OnAppearing()
{
base.OnAppearing();
GetContributions();
}
async private void GetContributions()
{
HttpClient client = new HttpClient();
client.DefaultRequestHeaders.Add("Accept", "application/json");
HttpResponseMessage response = await client
.GetAsync
(
"websiteURL.com"
);
if (response.IsSuccessStatusCode)
{
APIResponse data = JsonConvert.DeserializeObject<APIResponse>(response.Content.ReadAsStringAsync().Result);
if (data.ResponseCode == 1)
{
string payloadData = data.Data.ToString();
List<TextCell> userPosts = JsonConvert.DeserializeObject<List<TextCell>>(payloadData);
if (userPosts.Count == 0)
{
NoPostsMessage.IsVisible = true;
PostList.IsVisible = false;
}
else
{
NoPostsMessage.IsVisible = false;
PostList.IsVisible = true;
ReportsList.ItemsSource = userPosts;
}
}
else
{
await DisplayAlert("Error", data.ErrorMessage, "OK");
}
}
else
{
await DisplayAlert("Error", "An error has occurred, please try again later", "OK");
}
}
c# xaml xamarin xamarin.forms
asked Nov 12 '18 at 20:14
Farshad MomtazFarshad Momtaz
1691417
add a comment |
0
I'm trying to open a new page which shows a list that is populated with data from the server. The call to get the data from the server is done using an async function that is called from OnAppearing method. However, even though the method is async, my UI page is not shown until the call is done. How can I fix that or what is the best practice to make this call?
This is my XAML code for the page:
<StackLayout>
<Label
x:Name="NoPostsMessage"
Text="You have not created any posts yet :("
VerticalOptions="CenterAndExpand"
HorizontalOptions="CenterAndExpand" />
<ListView
x:Name="PostList"
SelectionMode="None">
<ListView.ItemTemplate>
<DataTemplate>
<TextCell Text="{Binding Text}" Detail="{Binding Detail}" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
This is my C# code:
protected override void OnAppearing()
{
base.OnAppearing();
GetContributions();
}
async private void GetContributions()
{
HttpClient client = new HttpClient();
client.DefaultRequestHeaders.Add("Accept", "application/json");
HttpResponseMessage response = await client
.GetAsync
(
"websiteURL.com"
);
if (response.IsSuccessStatusCode)
{
APIResponse data = JsonConvert.DeserializeObject<APIResponse>(response.Content.ReadAsStringAsync().Result);
if (data.ResponseCode == 1)
{
string payloadData = data.Data.ToString();
List<TextCell> userPosts = JsonConvert.DeserializeObject<List<TextCell>>(payloadData);
if (userPosts.Count == 0)
{
NoPostsMessage.IsVisible = true;
PostList.IsVisible = false;
}
else
{
NoPostsMessage.IsVisible = false;
PostList.IsVisible = true;
ReportsList.ItemsSource = userPosts;
}
}
else
{
await DisplayAlert("Error", data.ErrorMessage, "OK");
}
}
else
{
await DisplayAlert("Error", "An error has occurred, please try again later", "OK");
}
}
c# xaml xamarin xamarin.forms
asked Nov 12 '18 at 20:14
Farshad MomtazFarshad Momtaz
1691417
Why are you using.Resultin aasyncmethod?
– Cheesebaron
Nov 13 '18 at 16:07
@Cheesebaron, Thanks for pointing that out. I forgot to change that when I changed the method to async. I'll replace it with await
– Farshad Momtaz
Nov 14 '18 at 4:30
add a comment |
0
0
0
I'm trying to open a new page which shows a list that is populated with data from the server. The call to get the data from the server is done using an async function that is called from OnAppearing method. However, even though the method is async, my UI page is not shown until the call is done. How can I fix that or what is the best practice to make this call?
This is my XAML code for the page:
<StackLayout>
<Label
x:Name="NoPostsMessage"
Text="You have not created any posts yet :("
VerticalOptions="CenterAndExpand"
HorizontalOptions="CenterAndExpand" />
<ListView
x:Name="PostList"
SelectionMode="None">
<ListView.ItemTemplate>
<DataTemplate>
<TextCell Text="{Binding Text}" Detail="{Binding Detail}" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
This is my C# code:
protected override void OnAppearing()
{
base.OnAppearing();
GetContributions();
}
async private void GetContributions()
{
HttpClient client = new HttpClient();
client.DefaultRequestHeaders.Add("Accept", "application/json");
HttpResponseMessage response = await client
.GetAsync
(
"websiteURL.com"
);
if (response.IsSuccessStatusCode)
{
APIResponse data = JsonConvert.DeserializeObject<APIResponse>(response.Content.ReadAsStringAsync().Result);
if (data.ResponseCode == 1)
{
string payloadData = data.Data.ToString();
List<TextCell> userPosts = JsonConvert.DeserializeObject<List<TextCell>>(payloadData);
if (userPosts.Count == 0)
{
NoPostsMessage.IsVisible = true;
PostList.IsVisible = false;
}
else
{
NoPostsMessage.IsVisible = false;
PostList.IsVisible = true;
ReportsList.ItemsSource = userPosts;
}
}
else
{
await DisplayAlert("Error", data.ErrorMessage, "OK");
}
}
else
{
await DisplayAlert("Error", "An error has occurred, please try again later", "OK");
}
}
c# xaml xamarin xamarin.forms
asked Nov 12 '18 at 20:14
Farshad MomtazFarshad Momtaz
1691417
I'm trying to open a new page which shows a list that is populated with data from the server. The call to get the data from the server is done using an async function that is called from OnAppearing method. However, even though the method is async, my UI page is not shown until the call is done. How can I fix that or what is the best practice to make this call?
This is my XAML code for the page:
<StackLayout>
<Label
x:Name="NoPostsMessage"
Text="You have not created any posts yet :("
VerticalOptions="CenterAndExpand"
HorizontalOptions="CenterAndExpand" />
<ListView
x:Name="PostList"
SelectionMode="None">
<ListView.ItemTemplate>
<DataTemplate>
<TextCell Text="{Binding Text}" Detail="{Binding Detail}" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
This is my C# code:
protected override void OnAppearing()
{
base.OnAppearing();
GetContributions();
}
async private void GetContributions()
{
HttpClient client = new HttpClient();
client.DefaultRequestHeaders.Add("Accept", "application/json");
HttpResponseMessage response = await client
.GetAsync
(
"websiteURL.com"
);
if (response.IsSuccessStatusCode)
{
APIResponse data = JsonConvert.DeserializeObject<APIResponse>(response.Content.ReadAsStringAsync().Result);
if (data.ResponseCode == 1)
{
string payloadData = data.Data.ToString();
List<TextCell> userPosts = JsonConvert.DeserializeObject<List<TextCell>>(payloadData);
if (userPosts.Count == 0)
{
NoPostsMessage.IsVisible = true;
PostList.IsVisible = false;
}
else
{
NoPostsMessage.IsVisible = false;
PostList.IsVisible = true;
ReportsList.ItemsSource = userPosts;
}
}
else
{
await DisplayAlert("Error", data.ErrorMessage, "OK");
}
}
else
{
await DisplayAlert("Error", "An error has occurred, please try again later", "OK");
}
}
c# xaml xamarin xamarin.forms
c# xaml xamarin xamarin.forms
asked Nov 12 '18 at 20:14
Farshad MomtazFarshad Momtaz
1691417
asked Nov 12 '18 at 20:14
Farshad MomtazFarshad Momtaz
1691417
asked Nov 12 '18 at 20:14
Farshad MomtazFarshad Momtaz
1691417
asked Nov 12 '18 at 20:14
Farshad MomtazFarshad Momtaz
1691417
asked Nov 12 '18 at 20:14
Farshad MomtazFarshad Momtaz
1691417
1691417
Why are you using.Resultin aasyncmethod?
– Cheesebaron
Nov 13 '18 at 16:07
@Cheesebaron, Thanks for pointing that out. I forgot to change that when I changed the method to async. I'll replace it with await
– Farshad Momtaz
Nov 14 '18 at 4:30
add a comment |
Why are you using.Resultin aasyncmethod?
– Cheesebaron
Nov 13 '18 at 16:07
@Cheesebaron, Thanks for pointing that out. I forgot to change that when I changed the method to async. I'll replace it with await
– Farshad Momtaz
Nov 14 '18 at 4:30
Why are you using
.Result in a async method?– Cheesebaron
Nov 13 '18 at 16:07
Why are you using
.Result in a async method?– Cheesebaron
Nov 13 '18 at 16:07
@Cheesebaron, Thanks for pointing that out. I forgot to change that when I changed the method to async. I'll replace it with await
– Farshad Momtaz
Nov 14 '18 at 4:30
@Cheesebaron, Thanks for pointing that out. I forgot to change that when I changed the method to async. I'll replace it with await
– Farshad Momtaz
Nov 14 '18 at 4:30
add a comment |
1 Answer
1
active
oldest
votes
2
if you do not use await, the async call will block the UI
protected async override void OnAppearing()
{
base.OnAppearing();
await GetContributions();
}
answered Nov 12 '18 at 20:17
JasonJason
50.8k1290117
add a comment |
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
2
if you do not use await, the async call will block the UI
protected async override void OnAppearing()
{
base.OnAppearing();
await GetContributions();
}
answered Nov 12 '18 at 20:17
JasonJason
50.8k1290117
add a comment |
2
if you do not use await, the async call will block the UI
protected async override void OnAppearing()
{
base.OnAppearing();
await GetContributions();
}
answered Nov 12 '18 at 20:17
JasonJason
50.8k1290117
add a comment |
2
2
2
if you do not use await, the async call will block the UI
protected async override void OnAppearing()
{
base.OnAppearing();
await GetContributions();
}
answered Nov 12 '18 at 20:17
JasonJason
50.8k1290117
if you do not use await, the async call will block the UI
protected async override void OnAppearing()
{
base.OnAppearing();
await GetContributions();
}
answered Nov 12 '18 at 20:17
JasonJason
50.8k1290117
answered Nov 12 '18 at 20:17
JasonJason
50.8k1290117
answered Nov 12 '18 at 20:17
JasonJason
50.8k1290117
answered Nov 12 '18 at 20:17
JasonJason
50.8k1290117
50.8k1290117
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Why are you using
.Resultin aasyncmethod?– Cheesebaron
Nov 13 '18 at 16:07
@Cheesebaron, Thanks for pointing that out. I forgot to change that when I changed the method to async. I'll replace it with await
– Farshad Momtaz
Nov 14 '18 at 4:30