什么东西连toast，textview都不显示

[YXTS122]

public class MainActivity extends Activity implements OnClickListener {

	public static final int SHOW_LOCATION = 0;

	private TextView positionTextView;

	private LocationManager locationManager;

	private String provider;
	Button bt;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		positionTextView = (TextView) findViewById(R.id.position_text_view);
		bt=(Button)findViewById(R.id.button);
	}
	 @Override
	    public void onClick(View v) {
	        switch (v.getId()) {
	        case R.id.button:
		locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
		// 获取所有可用的位置提供器
		List<String> providerList = locationManager.getProviders(true);
		if (providerList.contains(LocationManager.GPS_PROVIDER)) {
			provider = LocationManager.GPS_PROVIDER;
		} else if (providerList.contains(LocationManager.NETWORK_PROVIDER)) {
			provider = LocationManager.NETWORK_PROVIDER;
		} else {
			// 当没有可用的位置提供器时，弹出Toast提示用户
			Toast.makeText(this, "没有可用的位置提供器",
					Toast.LENGTH_SHORT).show();
			return;
		}
		Location location = locationManager.getLastKnownLocation(provider);
		if (location != null) {
			// 显示当前设备的位置信息
			showLocation(location);
		}
		locationManager.requestLocationUpdates(provider, 5000, 1,
				locationListener);
		break;
		default:break;
	        }
	 }

	protected void onDestroy() {
		super.onDestroy();
		if (locationManager != null) {
			// 关闭程序时将监听器移除
			locationManager.removeUpdates(locationListener);
		}
	}

	LocationListener locationListener = new LocationListener() {

		@Override
		public void onStatusChanged(String provider, int status, Bundle extras) {
		}

		@Override
		public void onProviderEnabled(String provider) {
		}

		@Override
		public void onProviderDisabled(String provider) {
		}

		@Override
		public void onLocationChanged(Location location) {
			// 更新当前设备的位置信息
			showLocation(location);
		}
	};

	private void showLocation(Location location) {
		String currentPosition="纬度"+location.getLatitude()+"\n"+"经度"+location.getLongitude();
		positionTextView.setText(currentPosition);
		
	}

	

}  

[程序员一鸣]

少了一个注册监听：bt.setOnClickListener(this);

[YXTS122]

按照1楼和2楼的方法改后还是不显示自己所在的经纬度呀！

[顽固已死_有事烧纸]

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        positionTextView = (TextView) findViewById(R.id.position_text_view);
        bt=(Button)findViewById(R.id.button);
        bt.setOnClickListener(this);
    }

[YXTS122]

public class MainActivity extends Activity {

    public static final int SHOW_LOCATION = 0;

    private TextView positionTextView;

    private LocationManager locationManager;

    private String provider;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        positionTextView = (TextView) findViewById(R.id.position_text_view);
        Toast.makeText(getApplication(), "测试1",
                Toast.LENGTH_LONG).show();

        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        // 获取所有可用的位置提供器
        List<String> providerList = locationManager.getProviders(true);
        if (providerList.contains(LocationManager.GPS_PROVIDER)) {
            provider = LocationManager.GPS_PROVIDER;
            Toast.makeText(getApplication(), "测试4",
                    Toast.LENGTH_LONG).show();
        } else if (providerList.contains(LocationManager.NETWORK_PROVIDER)) {
            provider = LocationManager.NETWORK_PROVIDER;
            Toast.makeText(getApplication(), "测试5",
                    Toast.LENGTH_LONG).show();
        } else {
            // 当没有可用的位置提供器时，弹出Toast提示用户
            Toast.makeText(getApplication(), "没有可用的位置提供器",
                    Toast.LENGTH_LONG).show();
            return;
        }
        Toast.makeText(getApplication(), "测试2",
                Toast.LENGTH_LONG).show();
        Location location = locationManager.getLastKnownLocation(provider);
        if (location != null) {
            // 显示当前设备的位置信息
            showLocation(location);
        }
        else
        {
        	Toast.makeText(getApplication(), "测试3",
                    Toast.LENGTH_LONG).show();
        }
        locationManager.requestLocationUpdates(provider, 5000, 1,
                locationListener);

     }

    protected void onDestroy() {
        super.onDestroy();
        if (locationManager != null) {
            // 关闭程序时将监听器移除
            locationManager.removeUpdates(locationListener);
        }
    }

    LocationListener locationListener = new LocationListener() {

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {
        }

        @Override
        public void onProviderEnabled(String provider) {
        }

        @Override
        public void onProviderDisabled(String provider) {
        }

        @Override
        public void onLocationChanged(Location location) {
            // 更新当前设备的位置信息
            showLocation(location);
        }
    };

    public void showLocation(Location location) {
        String currentPosition="纬度"+location.getLatitude()+"\n"+"经度"+location.getLongitude();
        positionTextView.setText(currentPosition);

    }



}   

为什么location为null

[cattpon]

编译什么软件用的？

[左耳边的期盼]

添加这条试试：bt.setOnClickListener(this);