如何在片段中創建圖形？

Question

我想在一個片段中添加了曲線圖，但是我失敗了。我該怎麼做？

這裏是我的代碼片段：

public class Info extends Fragment 
{ 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) 
{ 
    return inflater.inflate(R.layout.info, container, false); 

    GraphView graph = (GraphView) findViewById(R.id.graph); 
    LineGraphSeries<DataPoint> series = new LineGraphSeries<DataPoint>(new DataPoint[] { 
      new DataPoint(0, 1), 
      new DataPoint(1, 5), 
      new DataPoint(2, 3), 
      new DataPoint(3, 2), 
      new DataPoint(4, 6) 
    }); 
    graph.addSeries(series); 
} 

} 

，當我嘗試運行我得到這個錯誤： GraphView圖=（GraphView）findViewById（R.id.graph）; 錯誤：（42，39）錯誤：無法找到符號方法findViewById（int）的

我也有這個在我的info.xml

<com.jjoe64.graphview.GraphView 
      android:layout_width="match_parent" 
      android:layout_height="125dp" 
      android:id="@+id/graph" /> 

但仍歌廳錯誤。

Answer 1

更新3：我誤解你的錯誤消息。我道歉。你的錯誤信息是說它找不到Fragment上的findViewById方法。這是因爲Fragments沒有這個方法，只有Activities才行。你必須得到一個關於你放大的視圖，然後調用view.findViewById（R.id.graph），如下面的代碼：

public View onCreateView(LayoutInflater inflater, ViewGroup container, 
        Bundle savedInstanceState) 
{ 
    View view = inflater.inflate(R.layout.info, container, false); 
    GraphView graph = (GraphView) view.findViewById(R.id.graph); 
    LineGraphSeries<DataPoint> series = new LineGraphSeries<DataPoint>(new 
     DataPoint[] { 
      new DataPoint(0, 1), 
      new DataPoint(1, 5), 
      new DataPoint(2, 3), 
      new DataPoint(3, 2), 
      new DataPoint(4, 6) 
    }); 
    graph.addSeries(series); 
    return view; 
} 

---

更新2：將您return語句的你的方法結束。就像這樣：

public View onCreateView(LayoutInflater inflater, ViewGroup container, 
        Bundle savedInstanceState) 
{ 
    GraphView graph = (GraphView) findViewById(R.id.graph); 
    LineGraphSeries<DataPoint> series = new LineGraphSeries<DataPoint>(new 
     DataPoint[] { 
      new DataPoint(0, 1), 
      new DataPoint(1, 5), 
      new DataPoint(2, 3), 
      new DataPoint(3, 2), 
      new DataPoint(4, 6) 
    }); 
    graph.addSeries(series); 
    return inflater.inflate(R.layout.info, container, false); 
} 

---

更新1：根據更新後的問題，你的代碼表明您從onCreateView內返回您與您的數據集的圖形之前。事實上，你不應該得到你得到的錯誤，因爲代碼永遠不會到達。這是我指的是代碼：

public View onCreateView(LayoutInflater inflater, ViewGroup container, 
        Bundle savedInstanceState) 
{ 
    return inflater.inflate(R.layout.info, container, false); 

    GraphView graph = (GraphView) findViewById(R.id.graph); 
    LineGraphSeries<DataPoint> series = new LineGraphSeries<DataPoint>(new 
     DataPoint[] { 
      new DataPoint(0, 1), 
      new DataPoint(1, 5), 
      new DataPoint(2, 3), 
      new DataPoint(3, 2), 
      new DataPoint(4, 6) 
    }); 
    graph.addSeries(series); 
} 

---

在你的問題的意見，你說你要

GraphView graph = (GraphView) findViewById(R.id.graph); Error:(42, 39) error: cannot find symbol method findViewById(int) 

這意味着你的佈局不具有控制使用android：id爲。檢查你的佈局，並確保你有一個控制android:id="@+id/graph"作爲一個屬性。