类似微信等待dialog转圈等待

运行效果如图：

LoadingDialog.java

import android.app.Dialog;
import android.content.Context;
import android.os.Bundle;
import android.widget.LinearLayout;
import android.widget.TextView;

public class LoadingDialog extends Dialog {
	private TextView tv;

	public LoadingDialog(Context context) {
		super(context, R.style.loadingDialogStyle);
	}

	private LoadingDialog(Context context, int theme) {
		super(context, theme);
	}

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.dialog_loading);
		tv = (TextView)this.findViewById(R.id.tv);
		tv.setText("正在上传...");
		LinearLayout linearLayout = (LinearLayout)this.findViewById(R.id.LinearLayout);
		linearLayout.getBackground().setAlpha(210);
	}
}

dialog_loading.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@android:color/transparent"
    android:gravity="center"
    android:orientation="vertical" >

    <LinearLayout
        android:id="@+id/LinearLayout"
        android:layout_width="160dp"
        android:layout_height="160dp"
        android:background="@drawable/dialog_bg"
        android:gravity="center"
        android:orientation="vertical" >

        <ProgressBar
            android:id="@+id/progressBar1"
            style="?android:attr/progressBarStyleInverse"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@android:color/transparent" />

        <TextView
            android:id="@+id/tv"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:paddingTop="10dp"
            android:textColor="@color/color_white"
             />
    </LinearLayout>

</LinearLayout>

MainActivity.java

public class MainActivity extends Activity {

	private Button login;
	private TextView jieguo;
	private EditText password, username;
	LoadingDialog dialog;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);		
		dialog = new LoadingDialog(this);
		dialog.setCanceledOnTouchOutside(false);
		dialog.show();

	}
}

style.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
   <style name="loadingDialogStyle" parent="android:Theme.Dialog">
        <item name="android:windowBackground">@android:color/transparent</item>
        <item name="android:windowFrame">@null</item>
        <item name="android:windowNoTitle">true</item>
        <item name="android:windowIsFloating">true</item>
        <item name="android:windowIsTranslucent">true</item>
        <item name="android:windowContentOverlay">@null</item>
 	<!-- 对话框是否有遮盖 -->
        <item name="android:windowAnimationStyle">@android:style/Animation.Dialog</item>
        <item name="android:backgroundDimEnabled">true</item>
    </style>
</resources>