Android LinearLayout 展开

Question

我正在使用以下代码来扩展特定的线性布局，并且遵循了本教程 http://gmariotti.blogspot.sg/2013/09/expand-and-collapse-animation.html

但是动画不是很流畅，有什么原因吗？

布局 XML

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context="com.techiequickie.bharath.parsetest.NewBet">

    <LinearLayout
        android:id = "@+id/mainLinear"
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:padding="30px"
        android:weightSum="1">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/bet_name_text"
            android:id="@+id/tv_Betname"
            android:textSize="@dimen/text_size_general"/>

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/et_Betname" />

        <Spinner
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/spin_Betcat1"
            android:spinnerMode="dropdown"
            android:entries="@array/bet_categories"/>

        <Spinner
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/spin_Betcat2"
            android:spinnerMode="dropdown"
            android:paddingTop="@dimen/spin_categories_space_between"
            android:entries="@array/bet_categories2"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/bet_value_text"
            android:id="@+id/bv_Betvalue"
            android:textSize="@dimen/text_size_general"/>

        <SeekBar
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/sb_Betvalue"
            android:max="10"
            android:progress="0"
            android:indeterminate="false" />

        <LinearLayout
            android:orientation="horizontal"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="0.15">

            <Switch
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Real Bet"
                android:id="@+id/switch_Betreal"
                android:checked="false" />
        </LinearLayout>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/bet_description"
            android:id="@+id/textView6"
            android:textSize="@dimen/text_size_general" />
    <LinearLayout
        android:id="@+id/collapsable"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="0.71">

        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:inputType="textMultiLine"
            android:ems="10"
            android:id="@+id/editText2"
            android:layout_weight="1" />
    </LinearLayout>

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/btn_Placebet"
            android:layout_gravity="center_horizontal"
            android:text="@string/place_bet_button" />

    </LinearLayout>
</RelativeLayout>

Activity 类

package com.techiequickie.bharath.parsetest;

import android.animation.*;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;


public class NewBet extends ActionBarActivity {

    LinearLayout mainlayout, collapsablelayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_new_bet);

        mainlayout = (LinearLayout) findViewById(R.id.mainLinear);
        collapsablelayout = (LinearLayout) findViewById(R.id.collapsable);

        collapsablelayout.setVisibility(View.GONE);

        mainlayout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(collapsablelayout.getVisibility()==View.GONE)
                {
                    expand();
                }
                else
                {
                    collapse();
                }
            }
        });
    }

    private void expand()
    {
        collapsablelayout.setVisibility(View.VISIBLE);

        final int widthSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        final int heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        collapsablelayout.measure(widthSpec, heightSpec);

        ValueAnimator mAnimator = slideAnimator(0, collapsablelayout.getMeasuredHeight());
        mAnimator.start();
    }

    private void collapse() {
        int finalHeight = collapsablelayout.getHeight();

        ValueAnimator mAnimator = slideAnimator(finalHeight, 0);

        mAnimator.addListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animation) {

            }

            @Override
            public void onAnimationEnd(Animator animator) {
                //Height=0, but it set visibility to GONE
                collapsablelayout.setVisibility(View.GONE);
            }

            @Override
            public void onAnimationCancel(Animator animation) {

            }

            @Override
            public void onAnimationRepeat(Animator animation) {

            }

        });
        mAnimator.start();
    }

    private ValueAnimator slideAnimator(int start, int end)
    {

        ValueAnimator animator = ValueAnimator.ofInt(start, end);

        animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator valueAnimator) {
                //Update Height
                int value = (Integer) valueAnimator.getAnimatedValue();
                ViewGroup.LayoutParams layoutParams = collapsablelayout.getLayoutParams();
                layoutParams.height = value;
                collapsablelayout.setLayoutParams(layoutParams);
            }
        });
        return animator;
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_new_bet, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

Answer 1

尝试将 android:animateLayoutChanges="true" 添加到线性布局