Question

我必须请求您帮助从Sliding Tab Layout中的片段调用方法。我检查了很多答案，但它们取决于我的项目不包括它们的id或标签。我用这个： javadocs for URL class 我有两个活动（MainActivity将两种数据发送到SecondActivity）。 SecondActivity包含带有3个片段的选项卡。在第一个片段（名为Contrs）中，我看到收到的数据（一种），但我想在我的操作栏中创建按钮，该按钮会更改第二种数据的结果。它在没有碎片但没有碎片的情况下工作。这是代码：

MainActivity：

public class MainActivity extends Activity { ...


public void count (View view) { 
    double g, x, y;
    g = Double.parseDouble(a.getText().toString());
    x = g*8.5;
    y = g*5.5;
    Intent sendingIntent = new Intent(this,SecondActivity.class);
    double x1 = new BigDecimal(x).setScale(2,RoundingMode.HALF_UP).doubleValue();
    double y1 = new BigDecimal(y).setScale(2,RoundingMode.HALF_UP).doubleValue();
    sendingIntent.putExtra("x1", x1);
    sendingIntent.putExtra("y1", y1);
    startActivity(sendingIntent);
...}

SecondActivity：

public class SecondActivity extends ActionBarActivity {
...
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.results, menu);
    MenuItem item = menu.findItem(R.id.alt);
    Intent receiveIntent = this.getIntent();
    y1 = receiveIntent.getDoubleExtra("y1", y1);
    if (y1 == 0) {
          item.setVisible(false); 
        } else { 
            item.setVisible(true);
        }
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) { 
        case R.id.alt:
           **"IN HERE I WANT TO MAKE A METHOD WHICH IS IN MY FRAGMENT"**
           break;
        case R.id.info:
           Intent intset1 = new Intent(this, A.class);
           this.startActivity(intset1);
           break;
        case R.id.help:
           Intent intset2 = new Intent(this, B.class);
           this.startActivity(intset2);
           return true;
        default:
            return super.onOptionsItemSelected(item);
    }
    return false;
}

Contrs：

public class Contrs extends Fragment {
...
public boolean aa = true;
public TextView vvv;
public double x1;
public double y1;
final DecimalFormat df = new DecimalFormat("0.00");

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v =inflater.inflate(R.layout.activity_contributions,container,false);
    x1 = getActivity().getIntent().getDoubleExtra("x1", x1);
    y1 = getActivity().getIntent().getDoubleExtra("y1", y1);

    vvv = (TextView) v.findViewById(R.id.r1);
return v; 
}

public void v1 () { //  first kind of data
    vvv.setText(String.valueOf(df.format(x1)));
}
public void v2 () { // second kind of data
    vvv.setText(String.valueOf(df.format(y1)));
}

public void alt (){ // switch between kinds
    if (aa)
        v1();
    else
        v2();
    aa = !aa;
}

我希望在SecondActivity中使用此方法（alt）。

Answer 1

你可以使用事件总线，这是更简单的

http://square.github.io/otto/

将您的片段注册到活动

并从活动中发送消息。

在你的情况下

BusProvider.java

public final class BusProvider {
  private static final Bus BUS = new Bus();

  public static Bus getInstance() {
    return BUS;
  }

  private BusProvider() {
    // No instances.
  }
}

ClickedItemEvent.java

public class ClickedItemEvent { //the name of the event
}

活动：

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) { 
        case R.id.alt:
        BusProvider.getInstance().post(new ClickedItemEvent());

片段：

public class YourFragment extends ... {
  ...

  @Override public void onResume() {
    super.onResume();
    BusProvider.getInstance().register(this);
  }

  @Override public void onPause() {
    super.onPause();
    BusProvider.getInstance().unregister(this);
  }

  @Subscribe public void onLocationChanged(ClickedItemEvent event) {
    //do anything you want
  }

  ...
}

滑动选项卡布局调用方法

1 个答案: