为什么我的 activity 没有显示？

Question

我正在尝试显示 Spinner 和 TextView，该应用程序运行但屏幕空白。这是我的 Java 代码

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.widget.ArrayAdapter;
import android.widget.Spinner;

import java.util.ArrayList;

/**
 * Created by ????? on 4/11/2015.
 */
public class CarSelectionActivity extends FragmentActivity {
    public void OnCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.new_car_screen);

        Spinner _make_spinner = (Spinner) findViewById(R.id.make_spinner);
        String[] spinnerArray= getResources().getStringArray(R.array.make_array);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>
                (this, android.R.layout.simple_spinner_item, spinnerArray);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        _make_spinner.setAdapter(adapter);


    }

}

这是我的XML布局代码

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
    <TextView
        android:id="@+id/textView1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Spinner Dropdown"
        android:layout_margin="5dp"
        android:padding="10dp"
        android:textSize="20dp"
        android:background="#ff5500"
        android:textColor="#fff"
        />

    <Spinner
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/textView1"
        android:popupBackground="#FFFF99"
        android:id="@+id/make_spinner"
        />




</RelativeLayout>

这是我的清单

<?xml version="1.0" encoding="utf-8"?>
<manifest
    xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.omnination.ossusum.gallonator" >

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
    <!--
 The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
         Google Maps Android API v2, but are recommended.
    -->
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />
        <meta-data
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="@string/google_maps_key" />

        <activity
            android:name=".CarSelectionActivity"
            android:label="Gallonator" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>

</manifest>

我的清单有我的地图片段的代码，但我还没有测试它。

Answer 1

你在这行有问题；-

android:方向="vertical"

Relativelayout--> 你不能给它添加 orientation 属性。删除此行

为什么我的 activity 没有显示？

Why isn't my activity showing?

xml

android

android-xml