[英]How to start Activity from another project
我正在為 android 和 windows-phone 開發天氣應用程序。 所以我在“解析類”中的“Weather.Api(Portable)”中的另一個項目中編寫了通用代碼。 “Weather.Droid”用於Android。
ParsingClass 的代碼如下:
public static string tempGlobal;
public static string cityTextGlobal;
private static string GovnoTemperature;
public async Task<string> dataByCity(string city)
{
var url = "http://api.openweathermap.org/data/2.5/weather?q=" + city + "&units=metric&APPID="+AppID;
//ТОРМОЗИТ ЗДЕСЬ / BRAKES HERE
await FetchAsync(url);
return city;
}
public async Task<double> Data_down(double lat, double lon)
{
var url = String.Format(
"http://api.openweathermap.org/data/2.5/weather?lat=" + lat + "&lon=" + lon + "&units=metric&APPID=" + AppID);
//ТОРМОЗИТ ЗДЕСЬ / BRAKES HERE
await FetchAsync(url);
return lat;
}
public async Task<string> FetchAsync(string url)
{
string jsonString;
using (var httpClient = new System.Net.Http.HttpClient())
{
var stream = await httpClient.GetStreamAsync(url);
StreamReader reader = new StreamReader(stream);
jsonString = reader.ReadToEnd();
}
var json = jsonString;
JsonValue firstitem = json;
var mydata = JObject.Parse(json);
cityTextGlobal = (mydata["name"]).ToString();
string GovnoData = (mydata["main"]).ToString();
//spliting string
string[] values = GovnoData.Split(',');
for (int i = 0; i < values.Length; i++)
{
values[i] = values[i].Trim();
if (i == 0)
{
//tempGlobal = values[i];
GovnoTemperature = values[i];
}
}
tempGlobal = null;
foreach (char c in GovnoTemperature)
{
if (c == '.')
{
break;
}
if (c == '-' || char.IsDigit(c) == true || c == '.')
{
tempGlobal += c.ToString();
}
}
return jsonString;
}
}
public class Coord
{
public double lon { get; set; }
public double lat { get; set; }
}
public class Weather
{
public int id { get; set; }
public string main { get; set; }
public string description { get; set; }
public string icon { get; set; }
}
public class Main
{
public double temp { get; set; }
public int pressure { get; set; }
public int humidity { get; set; }
public int temp_min { get; set; }
public int temp_max { get; set; }
}
public class Wind
{
public double speed { get; set; }
public double deg { get; set; }
}
public class Clouds
{
public int all { get; set; }
}
public class Sys
{
public int type { get; set; }
public int id { get; set; }
public double message { get; set; }
public string country { get; set; }
public int sunrise { get; set; }
public int sunset { get; set; }
}
public class RootObject
{
public Coord coord { get; set; }
public List<Weather> weather { get; set; }
public string @base { get; set; }
public Main main { get; set; }
public int visibility { get; set; }
public Wind wind { get; set; }
public Clouds clouds { get; set; }
public int dt { get; set; }
public Sys sys { get; set; }
public int id { get; set; }
public string name { get; set; }
public int cod { get; set; }
}
}
我需要從方法啟動“Weather.Droid”的 MainActivity:
公共異步任務 FetchAsync(string url)
在它返回之前:
json字符串
我怎樣才能做到這一點?
看起來你所追求的是依賴注入。 在可移植項目中聲明一個接口,然后在Droid/iOS/???中實現它你支持的項目。
我在 XLabs 社區項目中創建了 IOC 的抽象。 Matt Whetton 寫了一些關於如何使用它的非常好的說明: http : //www.codenutz.com/getting-started-xamarin-forms-labs-xaml-mvvm-ioc/
以下方法並不理想,但有點不清楚為什么您需要調用活動開始至少這會給您一些想法。
在便攜方面:
public class Class1
{
public static async Task<string> Fetch(string url, Action onComplete = null)
{
await Task.Delay(10);
onComplete?.Invoke();
return url;
}
}
在 Android 端(如果您的意圖是在主屏幕出現之前執行此提取,則這將是您的初始屏幕或應用程序):
[Activity(Label = "App5", MainLauncher = true, Icon = "@drawable/icon")]
public class MainActivity : Activity
{
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
// Set our view from the "main" layout resource
SetContentView (Resource.Layout.Main);
Class1.Fetch("test", () =>
{
var intent = new Intent(this, typeof(OtherActivity));
this.RunOnUiThread(() => StartActivity(intent));
}).ContinueWith(t =>
{
if (t.IsCompleted) Log.Debug("Fetch", t.Result);
});
}
}
我需要從方法啟動“Weather.Droid”的 MainActivity:
公共異步任務 FetchAsync(string url)
你不能直接從 Droid 項目啟動 MainActivity。 但正如@SKall 所說,您可以在FetchAsync
方法中使用Action<Intent>
:
//add Action<Intent> as and Intent as parameters
public async Task<string> FetchAsync(string url,Action<Intent> navigationFunc,Intent intent)
{
string jsonString;
...
navigationFunc(intent);//Invoke the action
return jsonString;
}
然后在你的 Droid 項目中使用它:
ParsingClass parsing = new ParsingClass();
Intent intent = new Intent(this, typeof(MainActivity));
await parsing.FetchAsync("url", StartActivity, intent);
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.