android中的Activity的开启StartActivity()和StartActivityForResult()

这几天接触android程序，在程序中看见StartActivity()函数，所以在网上百度的时候就出现了和StartActivityForResult()函数的比较，个人感觉比较好，所以就按照楼主给的Demo敲了一遍。但是由于楼主是粘贴的代码，所以给出来的部分不是太全，对于刚刚接触的新手来说遇见不少的问题。

写了一个关于开启Activity的Demo：共三个Activity：MainActivity用户填写用户姓名电话城市、CityActivity用于用户选择城市,ShowActivity用于展示用户信息。

首先我还是先把代码贴出来：

MainActivity.java：

package com.example.test;

import android.app.Activity;

import android.content.Intent;

import android.database.Cursor;

import android.net.Uri;

import android.os.Bundle;

import android.provider.ContactsContract.CommonDataKinds.Phone;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

public class MainActivity extends Activity implements OnClickListener {

private Button button_city,button_phone,button_save;

private EditText editText_city,editText_name,editText_phone;

private static final int SELECT_CITY_REQUEST =2;

private static final int SELECT_PHONE_REQUEST =3;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

button_city = (Button)findViewById(R.id.select_city);

button_phone = (Button)findViewById(R.id.phone1);

button_save = (Button)findViewById(R.id.save);

editText_city = (EditText)findViewById(R.id.editText_city);

editText_name = (EditText)findViewById(R.id.editText_name);

editText_phone = (EditText)findViewById(R.id.editText_phone);

button_city.setOnClickListener(this);

button_phone.setOnClickListener(this);

button_save.setOnClickListener(this);

}

public void onClick(View v) {

// TODO 自动生成的方法存根

switch (v.getId()) {

case R.id.select_city:

Intent i = new Intent ();

i.setClass(MainActivity.this, CityActivity.class);

startActivityForResult(i, SELECT_CITY_REQUEST);

break;

case R.id.phone1:

Intent pickContactIntent = new Intent(Intent.ACTION_PICK, Uri.parse("content://contacts"));

pickContactIntent.setType(Phone.CONTENT_TYPE);

startActivityForResult(pickContactIntent, SELECT_PHONE_REQUEST);

break;

case R.id.save:

String name=editText_name.getText().toString();

String city = editText_city.getText().toString();

String phone = editText_phone.getText().toString();

Intent saveIntent = new Intent(MainActivity.this,ShowActivity.class);

saveIntent.putExtra("content", "NAME: "+name+"\nCITY: "+city+"\nPHONE:"+phone);

startActivity(saveIntent);

break;

default:

break;

}

}

}

对应的layout配置：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context=".MainActivity" >

<TextView

android:id="@+id/textView1"

android:layout_width="wrap_content"

android:layout_height="wrap_content" >

</TextView>

<Button

android:id="@+id/name1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignTop="@+id/textView1"

android:layout_marginTop="28dp"

android:layout_toRightOf="@+id/textView1"

android:text="Name" />

<Button

android:id="@+id/city1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignLeft="@+id/name1"

android:layout_below="@+id/name1"

android:layout_marginTop="34dp"

android:text="City" />

<EditText

android:id="@+id/editText_name"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_above="@+id/city1"

android:layout_toRightOf="@+id/name1"

android:ems="10" >

<requestFocus />

</EditText>

<EditText

android:id="@+id/editText_city"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_above="@+id/phone1"

android:layout_toRightOf="@+id/city1"

android:ems="10"

android:inputType="textPersonName" />

<Button

android:id="@+id/select_city"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignBottom="@+id/editText_city"

android:layout_alignRight="@+id/editText_city"

android:text="select city" />

<Button

android:id="@+id/save"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignRight="@+id/namephone"

android:layout_below="@+id/phone1"

android:layout_marginTop="46dp"

android:layout_toRightOf="@+id/textView1"

android:text="save" />

<Button

android:id="@+id/phone1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_below="@+id/city1"

android:layout_marginTop="101dp"

android:text="select_phone" />

<EditText

android:id="@+id/editText_phone"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignBottom="@+id/namephone"

android:layout_toRightOf="@+id/namephone"

android:ems="10"

android:inputType="phone" />

<Button

android:id="@+id/namephone"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignBottom="@+id/phone1"

android:layout_marginBottom="47dp"

android:text="phone" />

save" />

</RelativeLayout>



CityActivity.java：

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.Gravity;

import android.view.View;

import android.view.ViewGroup;

import android.widget.AbsListView;

import android.widget.BaseExpandableListAdapter;

import android.widget.ExpandableListAdapter;

import android.widget.ExpandableListView;

import android.widget.LinearLayout;

import android.widget.TextView;

import android.widget.Toast;

public class CityActivity extends Activity {

private ExpandableListView eListView;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.layout_city);

initEListView();

}

private void initEListView() {

ExpandableListAdapter adapter = new BaseExpandableListAdapter() {

private String[] countries = new String[] { "China", "USA", "UK" };

private String[][] cities = new String[][] {

{ "BeiJing", "ShangHai", "HongKong", "TaiBei" },

{ "Washington", "New York", "Los Angles", "San Fransico" },

{ "London", "Manchester", "Birmingham", "Liverpool" } };

private TextView getTextView() {

AbsListView.LayoutParams lp = new AbsListView.LayoutParams(

ViewGroup.LayoutParams.MATCH_PARENT,

ViewGroup.LayoutParams.WRAP_CONTENT);

TextView textView = new TextView(CityActivity.this);

textView.setLayoutParams(lp);

textView.setGravity(Gravity.CENTER_HORIZONTAL);

textView.setPadding(0, 0, 0, 0);

textView.setTextSize(20);

return textView;

}

public boolean isChildSelectable(int groupPosition,

int childPosition) {

Toast.makeText(

CityActivity.this,

"you have clicked Group:" + groupPosition + "Child:"

+ childPosition + "\n"

+ countries[groupPosition] + " "

+ cities[groupPosition][childPosition],

Toast.LENGTH_SHORT).show();

Intent i = new Intent();

i.putExtra("city", cities[groupPosition][childPosition]);

setResult(RESULT_OK, i);

finish();

return true;

}

public boolean hasStableIds() {

return true;

}

public View getGroupView(int groupPosition, boolean isExpanded,

View convertView, ViewGroup parent) {

LinearLayout linearLayout = new LinearLayout(CityActivity.this);

linearLayout.setOrientation(0);

TextView textView = getTextView();

textView.setText(getGroup(groupPosition).toString());

linearLayout.addView(textView);

return linearLayout;

}

public long getGroupId(int groupPosition) {

return groupPosition;

}

public int getGroupCount() {

return countries.length;

}

public Object getGroup(int groupPosition) {

return countries[groupPosition];

}

public int getChildrenCount(int groupPosition) {

return cities[groupPosition].length;

}

public View getChildView(int groupPosition, int childPosition,

boolean isLastChild, View convertView, ViewGroup parent) {

TextView textView = getTextView();

textView.setText(getChild(groupPosition, childPosition)

.toString());

textView.setGravity(Gravity.CENTER_HORIZONTAL);

return textView;

}

public long getChildId(int groupPosition, int childPosition) {

return childPosition;

}

public Object getChild(int groupPosition, int childPosition) {

return cities[groupPosition][childPosition];

}

};

eListView = (ExpandableListView) findViewById(R.id.eListView);

eListView.setAdapter(adapter);

}

}

CityActivity对应的layout配置：



ShowActivity .java：

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.widget.TextView;

public class ShowActivity extends Activity{

private TextView showTextView;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.layout_show);

showTextView = (TextView)findViewById(R.id.textView1);

Intent i =getIntent();

String content = i.getStringExtra("content");

showTextView.setText(content);

}

}

ShowActivity 对应的layout配置文件：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context=".MainActivity" >

<TextView

android:id="@+id/textView2"

android:layout_width="wrap_content"

android:layout_height="wrap_content" >

</TextView>

<TextView

android:id="@+id/textView1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_below="@+id/textView2"

android:layout_marginLeft="62dp"

android:layout_marginTop="42dp"

android:layout_toRightOf="@+id/textView2"

android:text="TextView" />

</RelativeLayout>



运行成功后出现的画面：







其中在选择城市的界面，会有点小错误，希望有谁解决了可以跟我说一下：1143403680（qq）

在其中我出现的错误：

1：在mainactivity界面中，点击sclect_city按钮会闪退出程序，这是因为在cityactivity.java中，id号没有查找到：

eListView = (ExpandableListView) findViewById(R.id.eListView);

eListView.setAdapter(adapter);

2：刚接触android程序，在创建了三个activity时，要在清单中（AndroidManifest.xml文件中）添加上另外的activity：



3：还有就是上面提到的，虽然在ExpandableListView控件中可以显示城市名，但是会一闪而过，目前还没有解决。

好了，基本上我遇见的问题就这几个，也许是我愚笨了点，还望大神们多多指教。