fragment内部静态类和gradle问题

Question

最初我得到一个错误"这个片段内部类应该是静态的"在以下代码:

 public class Activity4 extends FragmentActivity {
    EditText mEdit;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_activity4);
    }

    public void selectDate(View view) {
    DialogFragment newFragment = new SelectDateFragment();
    newFragment.show(getSupportFragmentManager(), "DatePicker");
}
public void populateSetDate(int year, int month, int day) {
    mEdit = (EditText) findViewById(R.id.editText);
    mEdit.setText(day + "/" + month + "/" + year);
}
//error was here at SelectDateFragment
public class SelectDateFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener {
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        final Calendar calendar = Calendar.getInstance();
        int yy = calendar.get(Calendar.YEAR);
        int mm = calendar.get(Calendar.MONTH);
        int dd = calendar.get(Calendar.DAY_OF_MONTH);
        return new DatePickerDialog(getActivity(), this, yy, mm, dd);
    }
    public void onDateSet(DatePicker view, int yy, int mm, int dd) {
        populateSetDate(yy, mm + 1, dd);
    }
}
}

我试着找出解决方案&阅读这里的一些帖子，这是一个lint错误，可以通过将此添加到gradle文件中来解决:

lintOptions {
abortOnError false
}

但是当我这样做的时候，我得到的消息是"不能解析符号getDefaultProguardFile"。这是我的gradle文件:

apply plugin: 'com.android.application'
android {
compileSdkVersion 22
buildToolsVersion "22.0.1"
defaultConfig {
    applicationId "com.sample.pat1"
    minSdkVersion 16
    targetSdkVersion 22
    versionCode 1
    versionName "1.0"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
lintOptions {
    abortOnError false
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:22.2.0'
}

前面的错误"这个片段内部类应该是静态的"仍然存在。令人惊讶的是，尽管这一切，应用程序工作得很好。但我想知道我哪里做错了…请帮助!

Answer 1

如果您不想重写通信机制，您可以手动将fragment标记为有效的:

@SuppressLint("ValidFragment")
DialogFragment newFragment = new SelectDateFragment();

更多描述在这里

注: