Question

以下是代码：

<RelativeLayout android:id="@+id/TextDisplayLayout"
    android:layout_width="match_parent"
    android:layout_height="@dimen/PrintSetupTextHeight"
    android:layout_marginTop="45dp"
    android:layout_marginBottom="15dp">
</RelativeLayout>

和

public class MainScreen extends ActionBarActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main_screen);

    if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction()
                .add(R.id.container, new PlaceholderFragment()).commit();
    }

    RelativeLayout infoDisplay = (RelativeLayout) findViewById(R.id.TextDisplayLayout);
    TextView sdCardInfo = new TextView(this);
    sdCardInfo.setId(1);
    sdCardInfo.setText("SD Card Info Here");
    sdCardInfo.setLayoutParams(new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, 100));
    sdCardInfo.setBackgroundColor(Color.GRAY);
    sdCardInfo.setGravity(Gravity.CENTER);
    infoDisplay.addView(sdCardInfo);


}

我已将问题缩小到了 infoDisplay.addView（sdCardInfo）;

当这个部分被注释掉时，该应用程序可以工作，但显然我需要这部分代码。有人知道它为什么不起作用吗？

Answer 1

试试这个..

改变这个..

 setContentView(R.layout.activity_main_screen);

到

setContentView(R.layout.fragment_main_screen);

并删除

if (savedInstanceState == null) {
    getSupportFragmentManager().beginTransaction()
            .add(R.id.container, new PlaceholderFragment()).commit();
}

也

改变这个..

public class MainScreen extends ActionBarActivity

到

public class MainScreen extends Activity

OR

在PlaceholderFragment内 onCreateView

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.fragment_main_screen, container,
            false);
    RelativeLayout infoDisplay = (RelativeLayout) rootView.findViewById(R.id.TextDisplayLayout);
    TextView sdCardInfo = new TextView(getActivity());
    sdCardInfo.setId(1);
    sdCardInfo.setText("SD Card Info Here");
    sdCardInfo.setLayoutParams(new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, 100));
    sdCardInfo.setBackgroundColor(Color.GRAY);
    sdCardInfo.setGravity(Gravity.CENTER);
    infoDisplay.addView(sdCardInfo);

    return rootView;
}

Answer 2

试试这段代码......

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    RelativeLayout infoDisplay = (RelativeLayout) findViewById(R.id.TextDisplayLayout);
    TextView sdCardInfo = new TextView(this);
    sdCardInfo.setId(1);
    sdCardInfo.setText("SD Card Info Here");
    sdCardInfo.setLayoutParams(new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, 100));
    sdCardInfo.setBackgroundColor(Color.GRAY);
    sdCardInfo.setGravity(Gravity.CENTER);
    infoDisplay.addView(sdCardInfo);
    }
}

以编程方式将textview添加到relativelayout，导致应用程序停止？

2 个答案: