Xamarin开发Android笔记:使用ZXing进行连续扫描
在项目开发中需要使用到条码扫描,因为以前就测试过ZXing,感觉识别速度和功能都不错,所以直接引用。不过在实际开发的过程中,却遇到连续扫描的问题,每次扫描识别完成之后,扫描窗体自动关闭了。
在Xamarin论坛中查找解决方案,只是找到的iOS版本的解决方案。参考iOS的解决方案,其实就是在扫描完成之后重新打开扫描。按照这个思路,想到使用Intent for result的方式来进行实现。实现方法如下代码:
主窗体:
1 using System; 2 using Android.App; 3 using Android.Content; 4 using Android.Runtime; 5 using Android.Views; 6 using Android.Widget; 7 using Android.OS; 8 using ZXing.Mobile; 9 10 namespace imStudio.QRCodeLife 11 { 12 [Activity (Label = "imStudio.QRCodeLife", MainLauncher = true)] 13 public class MainActivity : Activity 14 { 15 int count = 1; 16 17 protected override void OnCreate (Bundle bundle) 18 { 19 base.OnCreate (bundle); 20 21 // Set our view from the "main" layout resource 22 SetContentView (Resource.Layout.Main); 23 24 // Get our button from the layout resource, 25 // and attach an event to it 26 var button = FindViewById<Button>(Resource.Id.myButton); 27 var tv = FindViewById<TextView>(Resource.Id.textView1); 28 29 button.Click += async delegate 30 { 31 StartActivityForResult(typeof(CodeActivity),1); 32 }; 33 } 34 35 protected override void OnActivityResult(int requestCode, Result resultCode, Intent data) 36 { 37 if (requestCode == 1) 38 { 39 if (resultCode == Result.Ok) 40 { 41 FindViewById<TextView>(Resource.Id.textView1).Text += data.GetStringExtra("Code") + System.Environment.NewLine; 42 StartActivityForResult(typeof(CodeActivity), 1); 43 } 44 } 45 } 46 } 47 }
子窗体,增加一个“完成”或“取消”按钮,用于关闭扫码窗体,代码如下:
using System; using System.Collections.Generic; using System.Linq; using System.Text; using Android.App; using Android.Content; using Android.OS; using Android.Runtime; using Android.Views; using Android.Widget; namespace imStudio.QRCodeLife { [Activity(Label = "CodeActivity")] public class CodeActivity : Activity { protected override async void OnCreate(Bundle bundle) { base.OnCreate(bundle); // Create your application here var scanner = new ZXing.Mobile.MobileBarcodeScanner(this); scanner.UseCustomOverlay = true; var zxingOverlay = LayoutInflater.FromContext(this).Inflate(Resource.Layout.Code, null); var doneButton = zxingOverlay.FindViewById<Button>(Resource.Id.buttonZxingDone); doneButton.Click += (sender, e) => { scanner.Cancel(); SetResult(Result.Canceled); Finish(); }; scanner.CustomOverlay = zxingOverlay; var result = await scanner.Scan(); HandleScanResult(result); } private void HandleScanResult(ZXing.Result result) { if (result != null) { Intent intent = new Intent(); intent.PutExtra("Code", result.Text); SetResult(Result.Ok,intent); Finish(); } } } }
实现代码虽然有些粗糙,不过功能OK,先用着,回头再想有没有好的办法。
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