对话框工具类

final ProgressDialog dialog = getProgressDialog("", "正在加载...");
dialog.show();

public ProgressDialog getProgressDialog(String title, String content) {
    	//实例化进度条对话框ProgressDialog
    	ProgressDialog dialog=new ProgressDialog(this);
    	
    	//可以不显示标题
    	dialog.setTitle(title);
    	dialog.setIndeterminate(true);
    	dialog.setMessage(content);
    	dialog.setCancelable(true);
    	return dialog;
}