Question

我正在开发一个应用程序，用户可以在其中输入血糖水平并将其显示在图表中。对于这个项目，我使用选项卡式导航，图表在Tab1上，输入在Tab2上。

我想这样做，以便当用户在Tab2上添加数据时，图表会自动更新Tab1。我会使用onStart（）进行图形更新;功能，但我不能，因为碎片不会关闭/重新打开，除非我在选项卡式导航中转到Tab3，因为android保存了最后2个打开的碎片。

Tab1

public class tab1 extends Fragment {

DatabaseHelper myDb;
LineGraphSeries<DataPoint> series;
SQLiteDatabase sqLiteDatabase;
GraphView graph;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    return inflater.inflate(R.layout.tab1, container, false);

}

public void onStart() {
    super.onStart();
    initControls();
    initGraph();

}




private void initControls() {

    myDb = new DatabaseHelper(getActivity());
    sqLiteDatabase = myDb.getReadableDatabase();

}
public void initGraph() {
    graph = getView().findViewById(R.id.graph);

    series = new LineGraphSeries<DataPoint>(getData());
    graph.addSeries(series);


    graph.getViewport().setXAxisBoundsManual(true);

    graph.getViewport().setScrollable(true);
    graph.getViewport().setScalable(true);
}

public void showMessage(String title, String Message) {
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    builder.setCancelable(true);
    builder.setTitle(title);
    builder.setMessage(Message);
    builder.show();
}


public DataPoint[] getData() {
    Cursor res = myDb.getAllData();

    DataPoint[] dp = new DataPoint[res.getCount()];

    if (res.getCount() == 0) {
        showMessage("Error", "Nothing Found");
    }
    for (int i = 0; i < res.getCount(); i++) {
        res.moveToNext();
        dp[i] = new DataPoint(res.getInt(0), res.getFloat(1));
    }

    return dp;
}
}

标签2

public class tab2 extends Fragment {

DatabaseHelper myDb;
private tab1 tb1 = new tab1();
EditText editText_Glucose;
Button btn_Add;

//Time today = new Time(Time.getCurrentTimezone());


@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    return inflater.inflate(R.layout.tab2, container, false);

}

public void onStart(){
    super.onStart();
    initControls();
}

private void initControls() {
    myDb = new DatabaseHelper(getActivity());

    editText_Glucose = getView().findViewById(R.id.editText_Glucose);
    btn_Add = getView().findViewById(R.id.btn_Add);

    AddData();

}

public void AddData() {
    btn_Add.setOnClickListener(
            new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    boolean isInserted = myDb.insertData(editText_Glucose.getText().toString());
                        if (isInserted)
                            showToast(getActivity(), "Data Inserted");
                        else
                            showToast(getActivity(), "Data not Inserted");
                }
            }
    );
}

public static void showToast(Context mContext, String message){
    Toast.makeText(mContext, message, Toast.LENGTH_SHORT).show();
}

}

Answer 1

为什么不为此使用TabLayout？

为此，请在主布局中添加：

<android.support.design.widget.TabLayout
            android:id="@android:id/tabs"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
/>

然后在你的活动或片段中onViewCreated（）：

    /* ... */
    mTabs = (TabLayout) view.findViewById(android.R.id.tabs);
    Tab tab1 = mTabs.newTab();
    Tab tab2 = mTabs.newTab();

    mTabs.addTab(tab1 , true);
    mTabs.addTab(tab2 , false);
   /* ... */

您可以查看本教程，了解有关TabLayout的更多详细信息： http://abhiandroid.com/materialdesign/tablayout-example-android-studio.html

从另一个片段更新Graph

1 个答案: