最近發現Android4.0系統中ProgressDialog設置爲setCancelable(true)時,點擊ProgressDialog以外的區域也可以讓ProgressDialog dismiss掉。但有時我們不希望是這樣的效果,於是將ProgressDialog設置setCancelable(false),再點擊ProgressDialog以外的區域就不會出現前面所說的情況了,然而這樣以來再按返回鍵時就不起作用了,只能等待程序執行到dissmiss處爲止。其實,只要爲ProgressDialog添加KeyListener來對返回鍵予以處理就可以解決這個問題了。
- package cn.winfirm.examples.base;
- import android.app.Activity;
- import android.app.ProgressDialog;
- import android.content.DialogInterface;
- import android.content.DialogInterface.OnKeyListener;
- import android.os.Bundle;
- import android.view.KeyEvent;
- import android.view.Window;
- /**
- * Activity的基類,帶一個ProgressDialog,可雙擊取消其顯示
- *
- * @author savant
- *
- */
- public class BaseActivity extends Activity {
- private ProgressDialog progressDialog = null;
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- requestWindowFeature(Window.FEATURE_NO_TITLE);
- }
- /**
- * show loading progress dialog
- */
- public void showDialog() {
- if (null == progressDialog) {
- progressDialog = ProgressDialog.show(BaseActivity.this, "", "正在加載,請稍候...");
- progressDialog.setCancelable(false);
- } else {
- progressDialog.show();
- }
- progressDialog.setOnKeyListener(onKeyListener);
- }
- /**
- * add a keylistener for progress dialog
- */
- private OnKeyListener onKeyListener = new OnKeyListener() {
- @Override
- public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
- if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN) {
- dismissDialog();
- }
- return false;
- }
- };
- /**
- * dismiss dialog
- */
- public void dismissDialog() {
- if (isFinishing()) {
- return;
- }
- if (null != progressDialog && progressDialog.isShowing()) {
- progressDialog.dismiss();
- }
- }
- /**
- * cancel progress dialog if nesseary
- */
- @Override
- public void onBackPressed() {
- if (progressDialog != null && progressDialog.isShowing()) {
- dismissDialog();
- } else {
- super.onBackPressed();
- }
- }
- }