.长效性对话框使用

private void keepDialog(DialogInterface dialog) {  //对话框出现期间不允许消失 包括点击返回
          try { 
              Field field = dialog.getClass().getSuperclass().getDeclaredField("mShowing"); 
              field.setAccessible(true); 
              field.set(dialog, false); 
          } catch (Exception e) { 
              e.printStackTrace(); 
          } 
      } 
 private void distoryDialog(DialogInterface dialog){  //对话框出现期间允许消失 包括点击返回
          try { 
              Field field = dialog.getClass().getSuperclass().getDeclaredField("mShowing"); 
              field.setAccessible(true); 
              field.set(dialog, true); 
          } catch (Exception e) { 
              e.printStackTrace(); 
          }  
      }