转载：Android Market的 Loading效果

在Android中,要实现Loading效果，一般情况下都使用ProgressDialog控件。ApiDemos/src/com/example/android/apis/view/ProgressBar3.java 提供两个demo:

仔细看了Android Market，发现却是不一样的，请看截图:

那到底如何实现呢？首先，我们创建一个布局文件,

res/layout/fullscreen_loading_indicator.xml, 其内容如下:

 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
      android:gravity="center_vertical|center_horizontal"
    android:orientation="horizontal"
    android:id="@+id/fullscreen_loading_style"
    
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"  
  >
  <ProgressBar 
  android:layout_gravity="center_vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
style="?android:attr/progressBarStyleSmall"
/>

<TextView
    android:id="@+id/current_action"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="5.0dip"
    android:text="@+string/loading"
/>
</LinearLayout>

然后在main.xml 把它include 进来

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <LinearLayout android:orientation="vertical" 
        android:id="@+id/main_info"
        android:visibility="gone" 
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
        <TextView android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:text="abc"></TextView>
    </LinearLayout>
    <LinearLayout android:orientation="vertical" 
        android:id="@+id/main_Loading"
        
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
        <include android:visibility="visible" 
            android:layout_width="fill_parent"
            android:layout_height="fill_parent" 
            layout="@layout/fullscreen_loading_style" />
    </LinearLayout>
</LinearLayout>

主程序：

package com.tymx.fullloading;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.LinearLayout;

public class myFullLoading extends Activity {
    /** Called when the activity is first created. */
    private LinearLayout mLoadingLayout;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        final Handler handler = new Handler(){

            @Override
            public void handleMessage(Message msg) {
                // TODO Auto-generated method stub
                super.handleMessage(msg);
                if (msg.what==1){
                    mLoadingLayout = (LinearLayout)findViewById(R.id.fullscreen_loading_style);
                    mLoadingLayout.setVisibility(View.GONE);
                    
                    LinearLayout mMain = (LinearLayout)findViewById(R.id.main_info);
                    mMain.setVisibility(View.VISIBLE);
                }                
                
            }
            
        };
        new Thread(){
            public void run(){
                for (int i=0;i<1000;i++){
                    System.out.print(i+"");
                }
                Message msg = handler.obtainMessage(1,"flash");
                handler.sendMessage(msg);
            }            
        }.start();
            
    }
}

运行的效果为: