Android開發中的正在加載動畫效果

有兩種實現效果，一種是系統默認效果，一種是自定義效果；默認效果比較簡單但效果也比較單調，自定義能夠作出比較好看的效果來；

第一種：經過建立一個ProgressDialog對象並設置屬性來顯示

public class Util {
    
    
    private static ProgressDialog processDia;

    /**
     * 顯示加載中對話框
     * 
     * @param context
     */
    public static void showLoadingDialog(Context context,String message,boolean isCancelable) {
        if (processDia == null) {
            processDia= new ProgressDialog(context,R.style.dialog);
            //點擊提示框外面是否取消提示框
            processDia.setCanceledOnTouchOutside(false);
            //點擊返回鍵是否取消提示框
            processDia.setCancelable(isCancelable);
            processDia.setIndeterminate(true);
            processDia.setMessage(message);
            processDia.show();  
        }
    }

    /**
     * 關閉加載對話框
     */
    public static void closeLoadingDialog() {
        if (processDia != null) {
            if (processDia.isShowing()) {
                processDia.cancel();
            }
            processDia = null;
        }
    }
}

其中style.xml中須要設置dialog的背景、字體等屬性

<style name="dialog" parent="@android:style/Theme.Dialog">
        <item name="android:windowFrame">@null</item>
        <item name="android:windowIsFloating">true</item>
        <item name="android:windowIsTranslucent">true</item>
        <item name="android:windowNoTitle">true</item>
        <item name="android:windowBackground">@android:color/transparent</item>
        <item name="android:backgroundDimEnabled">true</item>
        <item name="android:windowContentOverlay">@null</item>
        <item name="android:textSize">25sp</item>
</style>

第二種：首先要準備至少兩張圖片，圖片在切換的過程能夠造成動畫效果便可；

定義動畫切換特效，anim/loading.xml

<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android" android:oneshot="false" >
    <item android:drawable="@drawable/progress_loading_image_01" android:duration="150"/>
    <item android:drawable="@drawable/progress_loading_image_02" android:duration="150"/>
</animation-list>

自定義dialog頁面progress_dialog.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
   android:layout_gravity="center"
    android:orientation="vertical" >

    <ImageView
        android:id="@+id/loadingIv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@anim/loading"/>

    <TextView
        android:id="@+id/loadingTv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/loadingIv"
        android:layout_centerHorizontal="true"
        android:textSize="20sp"
        android:text="正在加載中.." />

</RelativeLayout>

建立diglog類MyProgressDialog

public class MyProgressDialog extends ProgressDialog {

    private AnimationDrawable mAnimation;
    private ImageView mImageView;
    private TextView mTextView;
    private String loadingTip;
    private int resid;

    /**
     * 
     * @param context 上下文對象
     * @param content 顯示文字提示信息內容
     * @param id 動畫id
     */
    public MyProgressDialog(Context context, String content, int resid) {
        super(context);
        this.loadingTip = content;
        this.resid = resid;
        //點擊提示框外面是否取消提示框
        setCanceledOnTouchOutside(false);
        //點擊返回鍵是否取消提示框
        setCancelable(false);
        setIndeterminate(true);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.progress_dialog);
        
        mTextView = (TextView) findViewById(R.id.loadingTv);
        mImageView = (ImageView) findViewById(R.id.loadingIv);
        
        mImageView.setBackgroundResource(resid);
        // 經過ImageView對象拿到背景顯示的AnimationDrawable
        mAnimation = (AnimationDrawable) mImageView.getBackground();
        
        mImageView.post(new Runnable() {
            @Override
            public void run() {
                mAnimation.start();
            }
        });
        mTextView.setText(loadingTip);
    }
}

最後在activity中進行調用，這樣就完成了一個自定義的dialog提示框

public class MainActivity extends Activity {
    private MyProgressDialog dialog;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btn = (Button)findViewById(R.id.btn_start);
        btn.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View view) {
                showMyDialog(view);
            }
        });
    }
    /**
     * 顯示對話框
     * @param v
     */
    public void showMyDialog(View v){
        dialog =new MyProgressDialog(this, "正在加載中",R.anim.loading);
        dialog.show();
        Handler handler =new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                dialog.dismiss();
            }
        }, 3000);
    }
}