我试图在不使用XML文件的情况下使用Fragments。 我的CustomView正在创建，但它的大小为零，因此没有调用onDraw。
我已经尝试过不同的方法，例如这里提到的方法：Custom onDraw() method not called 但我仍然不认为是画画。
这是我的CustomView类：
public class CameraView extends ConstraintLayout {
View view;
public CameraView(Context context) {
super(context);
initViews();
initLayouts();
}
void initViews() {
view = new View(this.getContext());
view.setBackgroundColor(Color.RED);
addView(view);
}
void initLayouts() {
// --------------------------------------------------
// use Android layout params to position subviews
// within this custom view class
// --------------------------------------------------
view.setId(View.generateViewId());
view.setLayoutParams(new LayoutParams(LayoutParams.MATCH_CONSTRAINT, LayoutParams.MATCH_CONSTRAINT));
ConstraintSet set = new ConstraintSet();
set.connect(view.getId(), ConstraintSet.START, ConstraintSet.PARENT_ID, ConstraintSet.START, 0);
set.connect(view.getId(), ConstraintSet.TOP, ConstraintSet.PARENT_ID, ConstraintSet.TOP, 0);
set.connect(view.getId(), ConstraintSet.END, ConstraintSet.PARENT_ID, ConstraintSet.END, 0);
set.connect(view.getId(), ConstraintSet.BOTTOM, ConstraintSet.PARENT_ID, ConstraintSet.BOTTOM, 0);
set.applyTo(this);
}
}
这是片段类：
public class CameraFragment extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
CameraView customView = new CameraView(getContext());
customView(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
return customView;
}
}
我注意到onCreateView ViewGroup container参数，根据文档，可用于生成视图的LayoutParams。
ViewGroup容器：如果为非null，则这是片段的UI应附加到的父视图。该片段不应该添加视图本身，但是这可以用于生成视图的LayoutParams。
但我不确定我是怎么做的，为了解决我的问题。
另外，我也尝试了另一种方法。而是在方法customView上创建我的onCreateView，我创建了一个容器并添加了customView后者，如此post中所做的那样：
public class CameraFragment extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
LinearLayout linearLayout = new LinearLayout(getContext());
linearLayout.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
linearLayout.setOrientation(LinearLayout.HORIZONTAL);
return linearLayout;
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
CameraView cameraView = new CameraView(getContext());
cameraView.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
LinearLayout linearLayout = (LinearLayout) view;
linearLayout.addView(cameraView);
}
但它也没有用。
编辑：
是
adb shell dumpsys activity top的输出？
TASK com.qwantech.blupper id=914
ACTIVITY com.qwantech.blupper/.MainActivity 7fbc9c7 pid=18837
Local FragmentActivity 83a63ad State:
mCreated=truemResumed=true mStopped=false mReallyStopped=false
mLoadersStarted=true
Active Fragments in 27f7663:
#0: CameraFragment{9e9c260 #0 id=0x1}
mFragmentId=#1 mContainerId=#1 mTag=null
mState=5 mIndex=0 mWho=android:fragment:0 mBackStackNesting=0
mAdded=true mRemoving=false mFromLayout=false mInLayout=false
mHidden=false mDetached=false mMenuVisible=true mHasMenu=false
mRetainInstance=false mRetaining=false mUserVisibleHint=true
mFragmentManager=FragmentManager{27f7663 in HostCallbacks{8013319}}
mHost=android.support.v4.app.FragmentActivity$HostCallbacks@8013319
mContainer=android.support.constraint.ConstraintLayout{46a8fde V.E...... ........ 0,0-1536,2000 #1}
mView=android.widget.LinearLayout{ce915bf V.E...... ......I. 0,0-0,0}
mInnerView=android.widget.LinearLayout{ce915bf V.E...... ......I. 0,0-0,0}
Child FragmentManager{498a48c in CameraFragment{9e9c260}}:
FragmentManager misc state:
mHost=android.support.v4.app.FragmentActivity$HostCallbacks@8013319
mContainer=android.support.v4.app.Fragment$2@768e7d5
mParent=CameraFragment{9e9c260 #0 id=0x1}
mCurState=5 mStateSaved=false mDestroyed=false
Added Fragments:
#0: CameraFragment{9e9c260 #0 id=0x1}
FragmentManager misc state:
mHost=android.support.v4.app.FragmentActivity$HostCallbacks@8013319
mContainer=android.support.v4.app.FragmentActivity$HostCallbacks@8013319
mCurState=5 mStateSaved=false mDestroyed=false
View Hierarchy:
com.android.internal.policy.PhoneWindow$DecorView{278f248 V.E..... ... 0,0-1536,2048}
android.widget.LinearLayout{20bcbea V.E..... ... 0,0-1536,2048}
android.view.ViewStub{8234edb G.E..... ... 0,0-0,0 #102046a android:id/action_mode_bar_stub}
android.widget.FrameLayout{1717d78 V.E..... ... 0,48-1536,2048}
android.support.v7.widget.FitWindowsLinearLayout{45d2c51 V.E..... ... 0,0-1536,2000 #7f0b004a app:id/action_bar_root}
android.support.v7.widget.ViewStubCompat{6d2bcb6 G.E..... ... 0,0-0,0 #7f0b004b app:id/action_mode_bar_stub}
android.support.v7.widget.ContentFrameLayout{7fdfdb7 V.E..... ... 0,0-1536,2000 #1020002 android:id/content}
android.support.constraint.ConstraintLayout{46a8fde V.E..... ... 0,0-1536,2000 #1}
android.widget.LinearLayout{ce915bf V.E..... ... 0,0-0,0}
com.qwantech.blupper.CameraView{cfcf924 V.E..... ... 0,0-0,0}
android.view.View{1773c8d V.ED.... ... 0,0-0,0 #2}
android.view.View{645ee42 V.ED.... ... 0,0-1536,48 #102002f android:id/statusBarBackground}
MainActivity.java
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ConstraintLayout container = new ConstraintLayout(getApplicationContext());
container.setId(View.generateViewId());
container.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
container.setBackgroundColor(Color.CYAN);
setContentView(container);
CameraFragment f = CameraFragment.newInstance();
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(container.getId(), f);
fragmentTransaction.commit();
}
}