MotionLayout + RecyvlerView items

Question

如何添加一个动态布局到项目回收器视图中，其中用户滚动时，列表中的每个项目都应该改变(动态布局进度应该改变)，而滚动时没有延迟?

Answer 1

这是一个复杂的问题，取决于您希望如何操作。

我们已经创建了一系列的例子

帮助解决两者同时使用的各种挑战。这是最有可能的问题，这是缓存屏幕外元素的状态。

如果是版本问题，请提供详细信息。

public class MotionRecycler2 extends AppCompatActivity {
class MyModel {
String name;
long countdown = 0;
CustomViewHolder view;
}
MyModel[] models = new MyModel[200];
RecyclerView recyclerView;
Handler handler = new Handler();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
for (int i = 0; i < models.length; i++) {
models[i] = new MyModel();
models[i].name = "done";
}
recyclerView = findViewById(R.id.recyclerView);
recyclerView.setAdapter(new CustomAdapter(models));
recyclerView.setLayoutManager(new LinearLayoutManager(this));
handler.postDelayed(new Runnable() {
@Override
public void run() {
for (int i = 0; i < models.length; i++) {
if (models[i].view != null)
models[i].view.upDateProgress();
}
handler.postDelayed(this, 100);
}
}, 100);
}
// ========================= The RecyclerView adapter =====================
static class CustomAdapter extends RecyclerView.Adapter<CustomViewHolder> {
private MyModel[] mModels;
public CustomAdapter(MyModel[] models) {
mModels = models;
}
@Override
public CustomViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
LayoutInflater inflater = LayoutInflater.from(viewGroup.getContext());
View view = inflater.inflate(R.layout.timer_item, viewGroup, false);
return new CustomViewHolder(view);
}
@Override
public void onBindViewHolder(CustomViewHolder viewHolder, final int position) {
if (viewHolder.mModel != null) {
viewHolder.mModel.view = null;
}
viewHolder.bind(mModels[position]);
}
@Override
public int getItemCount() {
return mModels.length;
}
}
// ========================= The View Holder adapter =====================
public static class CustomViewHolder extends RecyclerView.ViewHolder {
private final Button button;
private final MotionLayout mMotionLayout;
MyModel mModel;
boolean setting = false;
DecimalFormat decimalFormat = new DecimalFormat("##.000");
TransitionAdapter adapter = new TransitionAdapter() {
@Override
public void onTransitionChange(MotionLayout motionLayout, int startId, int endId, float progress) {
if (setting ) {
return;
}
mModel.countdown = calcDuration(progress) + System.currentTimeMillis();
upDateProgress();
}
};
public void click(View e) {
mModel.countdown = System.currentTimeMillis();
mMotionLayout.jumpToState(R.id.start);
}
public CustomViewHolder(View view) {
super(view);
mMotionLayout = (MotionLayout) view;
button = view.findViewById(R.id.button);
button.setOnClickListener(this::click);
}
public void upDateProgress() {
long duration = mModel.countdown -  System.currentTimeMillis();
if (duration <= 0) {
button.setText("done");
return;
}
setting = true;
mMotionLayout.setProgress(calcProgress(duration));
setting = false;
button.setText(decimalFormat.format(duration * 1E-3f));
}
private float calcProgress(long duration) {
return duration * 1E-5f;
}
private long calcDuration(float progress) {
return (long) (progress * 1E5);
}
public void bind(MyModel model) {
mModel = model;
model.view = this;
mMotionLayout.setTransitionListener(adapter);
button.setText(model.name);
if (mModel.countdown < System.currentTimeMillis()) {
mMotionLayout.jumpToState(R.id.start);
} else {
upDateProgress();
}
}
}
}