【移动应用开发技术】Android之Intent（二）

【移动应用开发技术】Android之Intent（二）

前一篇（Android之Intent（一））讲解过A（它用来调起B界面，这里先理解为父界面)可以向B（这里先理解为子界面），本篇正好是一个逆反的过程，即B向A传递数据。一：界面设计①，A（activity_main.xml）重要控件：1‘（TextView）txt_infos:用来显示从B交界面传过来的信息，默认值为XXXXXX2’（Button）btn_go_A:用来跳转至B界面如下图：②，B（activity_b2.xml）重要控件1‘（EditText）in_name:用来使用户输入文本2’（RadioGroup）rg_sex:单选组用来选择性别2-1‘（RadioButton）r_male:男2-2'(RadioButton)r_famale:女3'(Button)btn_ok:关闭按钮（向A界面发送信息）如下图：二：代码设计①，A：packagecom.example.kayer.aas;

importandroid.content.Intent;

importandroid.support.v7.app.AppCompatActivity;

importandroid.os.Bundle;

importandroid.view.View;

importandroid.widget.Button;

importandroid.widget.TextView;

importandroid.widget.Toast;

publicclassMainActivityextendsAppCompatActivity{

privateTextViewtxt_infos=null;

privateButtonbtn_go_A=null;

finalintREQ_GET_RESULT_4_B=100;

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

this.init();

}

privatevoidinit(){

this.txt_infos=(TextView)findViewById(R.id.txt_infos);

this.btn_go_A=(Button)findViewById(R.id.btn_go_A);

this.btn_go_A.setOnClickListener(newView.OnClickListener(){

@Override

publicvoidonClick(Viewv){

Intent$goto=newIntent(MainActivity.this,B2Activity.class);

startActivityForResult($goto,MainActivity.this.REQ_GET_RESULT_4_B);

}

});

}

@Override

protectedvoidonActivityResult(intrequestCode,intresultCode,Intentdata){

if(requestCode==this.REQ_GET_RESULT_4_B){

if(resultCode==RESULT_OK){

String$name=data.getStringExtra("name");

boolean$sex=data.getBooleanExtra("sex",false);

this.txt_infos.setText(

"姓名："+$name+"性别："+

($sex?"男":"女")

);

}

}

}

}

注意：1’finalintREQ_GET_RESULT_4_B=100;为请求码（需要自己定义）2‘RESULT_OK结果码，不需要自己定义②：Bpackagecom.example.kayer.aas;

importandroid.content.Intent;

importandroid.support.v7.app.AppCompatActivity;

importandroid.os.Bundle;

importandroid.view.View;

importandroid.widget.Button;

importandroid.widget.EditText;

importandroid.widget.RadioButton;

importandroid.widget.RadioGroup;

importandroid.widget.TextView;

importandroid.widget.Toast;

publicclassB2ActivityextendsAppCompatActivity{

privateEditTextin_name=null;

privateRadioGrouprg_sex=null;

privateRadioButtonr_male=null;

privateRadioButtonr_female=null;

privateButtonbtn_ok=null;

@Override

protectedvoidonCreate(BundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_b2);

this.init();

}

privatevoidinit(){

this.in_name=(EditText)findViewById(R.id.in_name);

this.rg_sex=(RadioGroup)findViewById(R.id.rg_sex);

this.r_male=(RadioButton)findViewById(R.id.r_male);

this.r_female=(RadioButton)findViewById(R.id.r_female);

this.btn_ok=(Button)findViewById(R.id.btn_ok);

this.btn_ok.setOnClickListener(newView.OnClickListener(){

@Override

publicvoidonClick(Viewv){

String$name=B2Activity.this.in_name.getText().toString().trim();

if($name.length()>0){

booleanmale=B2Activity.this.r_male.isChecked();

Intent$result=newIntent();

$result.putExtra("name",$name);

$result.putExtra("sex",male);

B2Activity.this.setResult(RESULT_OK,$result);

B2Activity.this.finish();

}else{

Toast.makeText(B2Activity.this,"请填写姓名！！！",Toast.LENGTH_SHORT).show();

}

}

});

this.rg_sex.setOnCheckedChangeListener(newRadioGroup.OnCheckedChangeListener(){

@Override

publicvoidonCheckedChanged(RadioGroupgroup,intcheckedId){

String$sex;

if(B2Activity.this.r_male.getId()==checkedId){

$sex="男";

}else{

$sex="女";

}