详解Android中App的启动界面Splash的编写方法

2019-12-10 18:54:36刘景俊

五、下载文件(使用Afinal框架)并调用系统安装工具安装APK

  if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
      FinalHttp finalHttp = new FinalHttp();
        finalHttp.download(apkurl,Environment.getExternalStorageDirectory().getAbsolutePath()+
         "/mobilesafe2.0.apk" , new AjaxCallBack<File>() {

          @Override
          public void onLoading(long count, long current) {
            super.onLoading(count, current);
            tv_uapdate_info.setVisibility(View.VISIBLE);
            int progress =(int) (current*100/count);
                tv_uapdate_info.setText("下载进度:"+progress+"%");
          }

          @Override
          public void onFailure(Throwable t, int errorNo,
              String strMsg) {
            t.printStackTrace();
            Toast.makeText(getApplicationContext(), "下载失败", 0).show();
            enterhome();

            super.onFailure(t, errorNo, strMsg);
          }

          @Override
          public void onSuccess(File t) {

            super.onSuccess(t);
            installAPK(t);

          }

          private void installAPK(File t) {
            Intent intent = new Intent();//自动安装程序可调用该段代码
            intent.setAction("android.intent.action.VIEW");
            intent.addCategory("android.intent.category.DEFAULT");
            intent.setDataAndType(Uri.fromFile(t), "application/vnd.android.package-archive");
            startActivity(intent);            
          }

        });

      }else{
        Toast.makeText(getApplicationContext(), "请插入内存卡再试",0).show();
        return;

      }

其他:

1、显示4.0的样式:方式是去掉功能清单里的Activity对应的android:theme;
放到application里面;

2、当splash页面弹出升级提示框过滤点击返回的是两种方式:

builder.setCancelable(false);
设置setOnCancelListener 当触屏的时候直接进入主页面

对话框是挂载在Activity上面的,如果Activity不存在,对话框就不能被创建。
getApplicationContext();生命周期长,只要应用还存活它就存在;this 生命周期短,只要Activity不存在了,系统就会回收
其中:getBaseContext(),getApplication(),getApplicationContext(); 都不能放在AlertDialog做上下文;