Question

我正在尝试在onCreate之后对方法中的视图（XML布局文件）进行充气和添加。父级是一个放置在FRAGMENT布局中的LinearLayout，我通过findView视图访问findViewById。但是我不能让视图膨胀/添加（它必须动态添加，因为用户添加了这些视图）。

我onCreate的片段：

CallFragment callFragment = (CallFragment) tabsPagerAdapter.getItem(1);
callRootView = callFragment.getView();

mainLayout = (LinearLayout)callRootView.findViewById(R.id.call_main_layout);

我的CreateCall方法的片段：

private void CreateCall()
{
    //try{
        LayoutInflater i = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        LinearLayout c = (LinearLayout)i.inflate(R.layout.call_display, null);
        //c.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT, 50));
        mainLayout.addView(c);
        Log.i("Success", "");
    /*}catch (Exception e) {
        Log.i("ERROR", e.toString());
    }*/
}

我的LogCat：

06-26 09:48:08.644  25001-25001/com.voytech.stockcall E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.voytech.stockcall, PID: 25001
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.voytech.stockcall/com.voytech.stockcall.MainActivity}: java.lang.NullPointerException
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
        at android.app.ActivityThread.access$800(ActivityThread.java:135)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5001)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
        at dalvik.system.NativeStart.main(Native Method)
 Caused by: java.lang.NullPointerException
        at com.voytech.stockcall.MainActivity.onCreate(MainActivity.java:148)
        at android.app.Activity.performCreate(Activity.java:5231)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
            at android.app.ActivityThread.access$800(ActivityThread.java:135)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5001)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
            at dalvik.system.NativeStart.main(Native Method)

MY SECOND APPROACH： 这段代码都在我的片段里面，仍然不起作用。从我的MainActivity访问该方法，希望这不是问题。 onCreateView：

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState)
{
    // Inflate the layout for this fragment
    rootView = inflater.inflate(R.layout.call_fragment, container, false);

    mainLayout = (LinearLayout) rootView.findViewById(R.id.call_main_layout);      //mainLayout references our direct LinearLayout(the container) in our XML document, this is also the parent that we will add the child view to

//Reference inflater and container if needed
layoutInflater = inflater;
        layoutContainer = container;
    }

这是 AddCallLayout 方法，它通过片段TabsPagerAdapter从我们的MainActivity中调用，我删除了一些注释掉的代码，因为这只是我尝试过的多种方法之一：

public void AddCallLayout()
{
    callDisplay = layoutInflater.inflate(R.layout.call_display, layoutContainer, false);
    mainLayout.addView(callDisplay);
}

Fragment LogCat：

06-26 10:38:13.840  14354-14354/com.voytech.stockcall E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.voytech.stockcall, PID: 14354
java.lang.NullPointerException
        at com.voytech.stockcall.CallFragment.AddCallLayout(CallFragment.java:146)
        at com.voytech.stockcall.MainActivity$2.onClick(MainActivity.java:675)
        at android.support.v7.app.AlertController$ButtonHandler.handleMessage(AlertController.java:153)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5001)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
        at dalvik.system.NativeStart.main(Native Method)

Android片段 - onCreateView后的Inflate / Add视图

0 个答案: