第二十二天 启动Activity和Intent

FrameLayout

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent">    <Button        android:layout_width="243dp"        android:layout_height="210dp"        android:id="@+id/button2"        android:layout_gravity="left|top" />    <Button        android:layout_width="193dp"        android:layout_height="152dp"        android:id="@+id/button3"        android:layout_gravity="left|top" /></FrameLayout>

TableLayout

<?xml version="1.0" encoding="utf-8"?><TableLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:stretchColumns="0,1,2"//下标从0开始    android:shrinkColumns="3,4">//可伸缩的列<TableRow>    <Button android:text="1"/>    <Button android:text="2"/>    <Button android:text="3"/></TableRow>    <TableRow>        <Button android:text="11"/>        <Button android:text="22"/>        <Button android:text="33"/>    </TableRow>    <TableRow>        <Button android:text="111"/>        <Button android:text="222"/>        <Button android:text="333"/>    </TableRow></TableLayout>

TableLayout的属性：

strechColumns 占用剩余空间（设置可伸展的列）
collapseColumns 隐藏某一列
shrinkColumns 设置可收缩的列

visibility（在界面中）

 android:visibility="gone"//不显示，不占空间 android:visibility="visible"//显示 android:visibility="invisible"//不显示，但占空间

启动Activity

1.直接启动Activity

Intent intent=new Intent(MainActivity.this,SecondActivity.class)startActivity(intent);

2.带有返回值的启动方式
(1)第一个界面调用startActivityForResult（intent，requestCode）； 例：startActivityForResult(intent,0x23)
(2)第二个界面先调用getIntent（）得到启动的intent,在关闭第二个界面前先封装数据intent.putExtra(“secondbackdata”,editText().toString());
(3)设置resultCode :setResult(RESULT_OK,intent)
(4)关闭第二个界面:SecondActivity.this.finish()
(5)第一个界面准备接受数据:
重写onActivityResult（requestCode，resultCode，Intent data）；
判断resultCode；
然后从data中取出数据

MainActivity中

protected void onActivityResult(int requestCode, int resultCode, Intent data) {        super.onActivityResult(requestCode, resultCode, data);        if(resultCode==RESULT_OK){            String s=data.getStringExtra("key");            textView.setText(s);        }    }

SecondActivity中

button.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {               intent= getIntent();                intent.putExtra("key", editText.getText().toString());                setResult(RESULT_OK,intent);                SecondActivity.this.finish();            }        });

去掉标题、信息栏，必须写在setContentview()前面

this.requestWindowFeature(Window.FEATURE_NO_TITLE);//去掉标题this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);//去掉信息栏screenORientation="portrait"(设置竖屏)screenOrientation="landscape"(设置横屏)

Android四大组件（五大组件Intent）

Activity、Service、ContentProvider、BroadcastReceive

Intent:Android通讯的

属性：action、component、data、category、type、extra

action（拨打电话、发信息、打开网页）

package com.example.administrator.myapplication;import android.app.Activity;import android.content.Intent;import android.net.Uri;import android.os.Bundle;import android.view.View;import android.widget.Button;/** * Created by Administrator on 2015/8/19. */public class IntentActivity extends Activity {    private Button mButtonPhone;    private Button mButtonCall;    private Button mButtonSms;    private Button mButtonWeb;    private Button mButtonHide;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.intent_layout);        mButtonPhone=(Button)findViewById(R.id.button_phone);        mButtonPhone.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent=new Intent();                intent.setAction(Intent.ACTION_DIAL);                intent.setData(Uri.parse("tel:[phone]"));                startActivity(intent);            }        });        mButtonCall=(Button)findViewById(R.id.button_call);        mButtonCall.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent = new Intent();                intent.setAction(Intent.ACTION_CALL);                intent.setData(Uri.parse("tel:[phone]"));                startActivity(intent);            }        });        mButtonSms=(Button)findViewById(R.id.button_sms);        mButtonSms.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent=new Intent(Intent.ACTION_SENDTO);          intent.setData(Uri.parse("smsto:18500292306"));                intent.putExtra("sms_body","The SMS Text");                startActivity(intent);            }        });        mButtonWeb=(Button)findViewById(R.id.button_web);        mButtonWeb.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent=new Intent(Intent.ACTION_VIEW);             intent.setData(Uri.parse("http://www.baidu.com"));                startActivity(intent);            }        });        //隐式启动        mButtonHide=(Button)findViewById(R.id.button_hide);        mButtonHide.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent=new Intent("com.example.administrator.myapplication");                startActivity(intent);            }        });    }}

隐式启动Activity

<intent-filter>    <action android:name="com.example.administrator.myapplication"/>    <category android:name="android.intent.category.DEFAULT"/></intent-filter>

 mButton5=(Button)findViewById(R.id.button_hide);        mButton5.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent=new Intent("com.example.administrator.myapplication");                startActivity(intent);            }        });

隐式启动MainActivity并获取信息

IntentActivity中：

 mButtonHide=(Button)findViewById(R.id.button_hide); mEditText=(EditText)findViewById(R.id.editText); mButtonHide.setOnClickListener(new View.OnClickListener() {       @Override        public void onClick(View v) {        Intent intent=new Intent("com.example.administrator.myapplication");        String s=mEditText.getText().toString();        intent.putExtra("key",s);        startActivity(intent);        } });

MainActivity中：

textView=(TextView)findViewById(R.id.textView);intent=getIntent();textView.setText(intent.getStringExtra("key"));