Android ListView头部随着上下拖动缩放

来源：互联网发布：方舟画质优化编辑：程序博客网时间：2024/05/21 09:25

效果图如下：

代码如下：

MainActivity：

public class MainActivity extends Activity {   private Button btn_fixed;   private Button btn_scale;      @Override   protected void onCreate(Bundle savedInstanceState) {      super.onCreate(savedInstanceState);      requestWindowFeature(Window.FEATURE_NO_TITLE);      setContentView(R.layout.activity_main);            btn_fixed = (Button) findViewById(R.id.btn_one);      btn_scale = (Button) findViewById(R.id.btn_two);            btn_fixed.setOnClickListener(new OnClickListener() {                  @Override         public void onClick(View v) {            Intent fixIntent = new Intent(MainActivity.this,FixedActivity.class);            startActivity(fixIntent);         }      });      btn_scale.setOnClickListener(new OnClickListener() {                  @Override         public void onClick(View v) {            Intent fixIntent = new Intent(MainActivity.this,ScaleActivity.class);            startActivity(fixIntent);         }      });   }}

FixedActivity代码：public class FixedActivity extends Activity implements OnScrollListener{      private ListView lv_test;   private LinearLayout ll_tt;   private TextView tv_shadow;   @Override   protected void onCreate(Bundle savedInstanceState) {      super.onCreate(savedInstanceState);      requestWindowFeature(Window.FEATURE_NO_TITLE);      setContentView(R.layout.activity_lv);      lv_test = (ListView) findViewById(R.id.lv_test);      tv_shadow = (TextView) findViewById(R.id.tv_shadow);            View view = LayoutInflater.from(this).inflate(R.layout.lv_test, null);      View view2 = LayoutInflater.from(this).inflate(R.layout.item, null);      ll_tt = (LinearLayout) view2.findViewById(R.id.ll_tt);            lv_test.addHeaderView(view);      lv_test.addHeaderView(view2);      lv_test.setOnScrollListener(this);      lv_test.setAdapter(new MyAdapter());   }      class MyAdapter extends BaseAdapter{      @Override      public int getCount() {         return 40;      }      @Override      public Object getItem(int position) {         return position;      }      @Override      public long getItemId(int position) {         return 0;      }      @Override      public View getView(int position, View convertView, ViewGroup parent) {         TextView tv = new TextView(FixedActivity.this);         tv.setText("listview"+position);         return tv;      }         }   @Override   public void onScrollStateChanged(AbsListView view, int scrollState) {   }   @SuppressLint("NewApi")   @Override   public void onScroll(AbsListView view, int firstVisibleItem,         int visibleItemCount, int totalItemCount) {      int top2 = ll_tt.getTop();      if (top2 <= 0 || firstVisibleItem >= 1 ) {         tv_shadow.setVisibility(View.VISIBLE);      }else {         tv_shadow.setVisibility(View.INVISIBLE);      }   }}
ScaleActivity代码如下：public class ScaleActivity extends Activity implements OnScrollListener{   private ListView lv_test;   private LinearLayout ll_tt;   private TextView tv;   private int top;   private float scale = 1;      @Override   protected void onCreate(Bundle savedInstanceState) {      super.onCreate(savedInstanceState);            requestWindowFeature(Window.FEATURE_NO_TITLE);      setContentView(R.layout.activity_lv);      lv_test = (ListView) findViewById(R.id.lv_test);            View view = LayoutInflater.from(this).inflate(R.layout.lv_test, null);      View view2 = LayoutInflater.from(this).inflate(R.layout.item, null);      ll_tt = (LinearLayout) view2.findViewById(R.id.ll_tt);      tv = (TextView) view2.findViewById(R.id.tv_tt);            lv_test.addHeaderView(view);      lv_test.addHeaderView(view2);      lv_test.setOnScrollListener(this);      lv_test.setAdapter(new MyAdapter());   }      @Override   protected void onResume() {      super.onResume();      ViewTreeObserver vto = ll_tt.getViewTreeObserver();      vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {         @Override         public void onGlobalLayout() {            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {               ll_tt.getViewTreeObserver().removeOnGlobalLayoutListener(this);            }            top = ll_tt.getTop();            scale = (float) scale / (float) top;            System.out.println("scale : " + scale);         }      });   }      class MyAdapter extends BaseAdapter{      @Override      public int getCount() {         return 40;      }      @Override      public Object getItem(int position) {         return position;      }      @Override      public long getItemId(int position) {         return 0;      }      @Override      public View getView(int position, View convertView, ViewGroup parent) {         TextView tv = new TextView(ScaleActivity.this);         tv.setText("listview"+position);         return tv;      }         }   @Override   public void onScrollStateChanged(AbsListView view, int scrollState) {   }   @Override   public void onScroll(AbsListView view, int firstVisibleItem,         int visibleItemCount, int totalItemCount) {      int top2 = ll_tt.getTop();      if (top2 >= 0) {         tv.setScaleX(top2 * scale);         tv.setScaleY(top2 * scale);      }   }}activity_main代码如下：

<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:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".MainActivity" >    <Button        android:id="@+id/btn_one"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="title固定"  />    <Button        android:id="@+id/btn_two"        android:layout_below="@id/btn_one"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="title缩放"  /></RelativeLayout>
 activity_lv代码如下：<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:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    android:background="#ffffffff"    tools:context=".MainActivity" >    <ListView         android:id="@+id/lv_test"        android:background="#ffffffff"        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:divider="@null"        android:dividerHeight="0dp"        android:scrollbars="none"  />    <TextView         android:id="@+id/tv_shadow"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:textSize="30sp"        android:text="这是测试条目"        android:background="#ffffffff"        android:visibility="invisible"        android:gravity="center"/></RelativeLayout>

lv_text代码如下：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="#ffffffff"    android:id="@+id/ll"    android:orientation="vertical" >        <ImageView         android:id="@+id/iv"        android:layout_width="wrap_content"        android:layout_height="200dp"        android:background="@mipmap/widget_autoscroollview_demo_banner1" /></LinearLayout>
item代码如下：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:id="@+id/ll_tt"    android:orientation="vertical" >       <TextView         android:id="@+id/tv_tt"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:textSize="30sp"        android:text="这是测试条目"        android:visibility="visible"        android:gravity="center"/></LinearLayout>

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