RequestCode and ResultCode

本文详细解释了startActivityForResult方法的工作原理及其应用场景。介绍了如何利用requestCode参数区分不同Activity的回调,以及如何使用resultCode来处理多种返回结果。此外,还提供了Intent传递数据的方法。

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startActivityForResult(Intent intent, Int requestCode)

If requestCode >= 0, this code will be returned in onActivityResult() when the activity exits. 

If requestCode < 0, be similar to startActivity(Intent intent) and this method onActivityResult() will not to perform.


startActivityForResult(intent, requestCode)首先文档告诉我们,只有到activity结束的时候,才会返回消息。

两个参数 ,第一个不用多说。第二个requestCode,一般情况下,我们只需要保证requestCode>-1即可,这样它都能收到result。
=======================================================================================

(1)如果在A activity中,能够跳转到多个activiity,并且要接受到这多个activity中的信息的时候,我们就要注意了,这时候,requestCode就起大作用了,当你startActiviityForResult()的时候, 给每一个不同的activity一个独立的requestcode,那么在你接受到result的时候就可以通过这个参数来判断,结果是那个acitivity返回来的了。

(2)如果是A activity跳转到B activity的时候,b有可能返回N种结果,而你在A中需要根据这N中不通的返回结果做出N种不通的处理的时候那该怎么办呢?当然,你可以用data中添加数据了识别,但是android提供了更好的一种方式,那就是onActivityResult(requestCode, resultCode, data)中的resultcode,你可以setresult()的时候,根据不通的结果返回不同的resultcode,这样就能区分开来。

=======================================================================================

put data

Intent intent = new Intent(MainActivity.this,ReceiveActivity.class);
                
	/** put array list. */
	ArrayList<HashMap<String, String>> listItem = new ArrayList<HashMap<String, String>>();
	intent.putExtra("listItem", listItem);
	/** put bundle. */
	Bundle b = new Bundle();
	b.putString("msg", et_input.getText().toString());
	intent.putExtras(b);
	/** put String */
	intent.putExtra("msg", et_input.getText().toString());
	startActivityForResult(intent, REQUEST_CODE);

get data

Intent intent = getIntent();
        
        String msg = intent.getStringExtra("msg");
        /** bundle data */
        String msg1 = intent.getExtras().getString("msg");

public static final int RESULT_OK

Since: API Level 1
Standard activity result: operation succeeded.

Constant Value: -1 (0xffffffff)

而onActivityResult中对resultCode的处理都是用这种架构:

public void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case REQUEST_CONNECT_DEVICE:
if (resultCode == Activity.RESULT_OK) {
...
} else {
}
break;
case REQUEST_ENABLE_BT:
if (resultCode == Activity.RESULT_OK) {
...
} else {
}



import androidx.annotation.Nullable; import androidx.appcompat.app.AppCompatActivity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.TextView; import android.widget.Toast; import com.google.zxing.integration.android.IntentIntegrator; import com.google.zxing.integration.android.IntentResult; public class MainActivity extends AppCompatActivity { private Button btnScan; private TextView tvResult; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); btnScan = findViewById(R.id.btnScan); tvResult = findViewById(R.id.tvResult); btnScan.setOnClickListener(v -> { // 初始化扫描器 IntentIntegrator integrator = new IntentIntegrator(this); integrator.setDesiredBarcodeFormats(IntentIntegrator.QR_CODE); // 只扫描二维码 integrator.setPrompt("将二维码放入扫描框内"); // 提示文字 integrator.setCameraId(0); // 使用后置摄像头 integrator.setBeepEnabled(true); // 扫描成功提示音 integrator.setOrientationLocked(false); // 允许旋转 integrator.initiateScan(); // 启动扫描 }); } // 接收扫描结果 @Override protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) { super.onActivityResult(requestCode, resultCode, data); IntentResult result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data); if (result != null) { if (result.getContents() == null) { Toast.makeText(this, "扫描已取消", Toast.LENGTH_SHORT).show(); } else { // 显示扫描结果 tvResult.setText("扫描结果: " + result.getContents()); } } } } 提示Unused import statement如何解决
最新发布
07-22
using Dapper; using Microsoft.AspNetCore.Mvc; using Microsoft.Data.SqlClient; using NHisApi.Models; using System.Data; namespace NHisApi.Controllers { [ApiController] [Route("api/[controller]")] public class AddLisController : ControllerBase { private readonly IConfiguration _config; public AddLisController(IConfiguration config) { _config = config; } public class queryRequest { public string jzhm { get; set; } public string doccode { get; set; } } [HttpPost] public async Task<IActionResult> AddLis([FromBody] queryRequest request) { using var hisConn = new SqlConnection(_config.GetConnectionString("his")); using var lisConn = new SqlConnection(_config.GetConnectionString("lis")); try { var ghmx = await hisConn.QueryFirstOrDefaultAsync<Ghmx>( "SELECT id, sbxh as ghxh FROM ms_ghmx WHERE jzhm = @Jzhm", new { request.jzhm }); if (ghmx == null) return StatusCode(200, new { resultcode = 500, message = "未找到挂号记录" }); var yj01 = await hisConn.QueryFirstOrDefaultAsync<Yj01>( "SELECT STUFF(\r\n (SELECT ',' + a.checktype + CONVERT(varchar(20), SQID)\r\n FROM MS_YJ01 a\r\n WHERE a.FPHM IS NULL \r\n AND a.ZXPB = 0 \r\n AND a.checktype = 'JY'\r\n AND a.ghxh = @ghxh\r\n FOR XML PATH('')), 1, 1, '') AS SQID", new { ghmx.Ghxh }); if (yj01 == null) return StatusCode(200, new { resultcode = 500, message = "未找到医嘱记录" }); var parameters = new { where = yj01.SQID, mainid = request.doccode + ghmx.Id }; var lisData = await lisConn.QueryAsync<LisFeeItem>( "sp_ruimeilis_getattchfee", parameters, commandType: CommandType.StoredProcedure); return StatusCode(200, new { resultcode = 200 }); } catch (Exception ex) { return StatusCode(500, new { resultcode = 500, message = "失败", error = ex.Message }); } } public class Ghmx { public int Id { get; set; } public string Ghxh { get; set; } } public class Yj01 { public string SQID { get; set; } } public class LisFeeItem { public string sfxmdh { get; set; } public int itemnum { get; set; } } } } 现在需要把 lisData 里面的值 通过循环 调用his的存储过程NHis_Cxf 入参为@ghxh,@sfxmdh,@itemnum,@mainid
03-08
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