C#开发移动应用系列(4.调用系统应用,以及第三方应用(调用与被调用))

 protected override void OnCreate(Bundle bundle)
  {
 //获取按钮
  var btn3 = FindViewById<Button>(Resource.Id.button3);
  //添加点击事件
  btn3.Click += delegate
   {
      //do...
    }
}

Android.Net.Uri uri = Android.Net.Uri.Parse("tel:18678445447");
 Intent it = new Intent(Intent.ActionDial, uri);
 StartActivity(it);

                    // 发送短信
                    Android.Net.Uri uri = Android.Net.Uri.Parse("smsto:10010");
                    Intent it = new Intent(Intent.ActionSendto, uri);
                    it.PutExtra("sms_body", "你妹妹,我没欠费 你给我停机!");
                    StartActivity(it);

 Android.Net.Uri uri = Android.Net.Uri.Parse("geo:38.899533,-77.036476");
 Intent it = new Intent(Intent.ActionView, uri);
 StartActivity(it);

Android.Net.Uri uri = Android.Net.Uri.Parse("mailto:777@qq.com?cc=aa@qq.com&subject=标题&body=内容");
var intent = new Intent(Intent.ActionView,uri);
 StartActivity(intent);

//第一种(建议使用第一种)
 Android.Net.Uri uri = Android.Net.Uri.Parse("content://contacts/people");
Intent it = new Intent(Intent.ActionPick, uri);
StartActivityForResult(it, 11);
//第二种 
Intent i = new Intent();
 i.SetAction(Intent.ActionGetContent);
 i.SetType("vnd.android.cursor.item/phone");
 StartActivityForResult(i, 11);

                    Intent i = new Intent();
                    i.SetType("image/*");
                    i.SetAction(Intent.ActionPick);
                    StartActivityForResult(i,11);

        protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
        {
            //base.OnActivityResult(requestCode, resultCode, data);

            //如果当初的发的requestCode =1
            if (requestCode == 1 && resultCode == Result.Ok)
            { 
               
                webView.LoadUrl(data.GetStringExtra("code"));
                Toast.MakeText(this, "扫描结果:" + data.GetStringExtra("code"), ToastLength.Short).Show();
            }
            if(requestCode == 11 && resultCode == Result.Ok)
            {
               //获得返回值
                Android.Net.Uri uri = data.Data;
               //转换返回值,得到文件地址
                var sdCardPath = Android.OS.Environment.ExternalStorageDirectory.AbsolutePath;
                var filePath = System.IO.Path.Combine(sdCardPath, data.DataString);
                ContentResolver resolver = this.ContentResolver;
                string[] pojo = { MediaStore.Images.Media.InterfaceConsts.Data };
                var cursor = this.ContentResolver.Query(uri, pojo, null, null, null);
                int column_index = cursor.GetColumnIndex(MediaStore.Images.Media.InterfaceConsts.Data);
                cursor.MoveToFirst();
                var path = cursor.GetString(column_index);
                //通过文件地址获得文件流
                FileStream fs = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Read);
                BinaryReader r = new BinaryReader(fs);
                r.BaseStream.Seek(0, SeekOrigin.Begin);    //将文件指针设置到文件开
                byte[] pReadByte = r.ReadBytes((int)r.BaseStream.Length);
                ShowMessage("读取到文件,字节长度:" + pReadByte.Length);
            }
        }

 // 打开发送属性的应用
 var ite = new Intent(Intent.ActionSend);
 ite.PutExtra(Intent.ExtraText, "发送数据:XXXXX");
 StartActivity(Intent.CreateChooser(ite, "选择应用程序"));

if (Intent.ActionSend == action)
 {
                //得到发过来的数据
                var sendtext = this.Intent.Extras.GetString(Intent.ExtraText);
                //弹出显示
                Toast.MakeText(this, sendtext, ToastLength.Long).Show();
                //显示到文本控件
                var textview = FindViewById<TextView>(Resource.Id.textView1);
                textview.Text = sendtext;
 }