Android 更改导航抽屉中的项目

Question

我想更改导航抽屉布局中 6 项的文本样式。所以我尝试了：

for(int i = 0; i < 6; i++){
    TextView tx = (TextView) mDrawerList.getAdapter().getView(i, null, null).findViewById(R.id.title);
    tx.setTypeface(semibold);
    tx.setTextSize(20);
}

但没有任何改变。 在我的 onItemClick 方法中，我得到了项目的视图，所以很容易在那里做：

@Override
    public void onItemClick(AdapterView<?> parent, View view, int position,
                            long id) {
        TextView tv = (TextView) view.findViewById(R.id.textView_title);
        tv.setTypeface(semibold);
        tv.setTextSize(20);
    }

如何在 onItemClick 方法之外更改项目的样式，如何引用项目的视图？

编辑： 将 getView 更改为 getChildAt 后，我​​得到了这个异常

02-12 20:16:51.736    8133-8133/example.de.example E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: example.de.example, PID: 8133
java.lang.RuntimeException: Unable to start activity ComponentInfo{example.de.example/example.de.example.MainActivity}: java.lang.NullPointerException
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2338)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390)
        at android.app.ActivityThread.access$800(ActivityThread.java:151)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321)
        at android.os.Handler.dispatchMessage(Handler.java:110)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:5292)
        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:824)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
        at dalvik.system.NativeStart.main(Native Method)
 Caused by: java.lang.NullPointerException
        at example.de.example.MainActivity.onCreate(MainActivity.java:155)
        at android.app.Activity.performCreate(Activity.java:5264)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1088)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:
at android.app.ActivityThread.access$800(ActivityThread.java:
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:
at android.os.Handler.dispatchMessage(Handler.java:
at android.os.Looper.loop(Looper.java:
at android.app.ActivityThread.main(ActivityThread.
at java.lang.reflect.Method.invokeNative(Native at java.lang.reflect.Method.invoke(Method.java:
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:
at dalvik.system.NativeStart.main(Native Method)

Answer 1

您对getView 的这些调用会创建您的ListView 从未实际使用过的新视图。

您需要通过ListView 获取视图，而不是通过它的适配器：

mDrawerList.post(new Runnable() {
    @Override
    public void run() {
        // Loop all children and set the TextView's typeface
        for(int i=0; i<mDrawerList.getChildCount(); i++){
            View child = mDrawerList.getChildAt(i);
            TextView tx = (TextView) child.findViewById(R.id.title);
            if (tx == null) {
                Log.e("TAG", "TextView at " + i + " not found!");
                continue;
            }
            tx.setTypeface(semibold);
            tx.setTextSize(20);
        }
    }
});