本文主要是介绍Android显式意图、隐式意图、意图过滤器(intent-filter)、意图间传值,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
intent主要包括隐式意图和显式意图。显式意图通常主要是启动本应用中的Activity之间的数据,而隐式意图则常见于启动系统中的某些特定的动作,比如打电话,发短信,或者是跨应用的Activity启动(如在QQ点击链接地址启动一个浏览器Activity)。显式意图:调用Intent.setComponent()、Intent.setClass()、Intent.setClassName()方法明确指定了组件名的Intent为显式意图,显式意图明确指定了Intent应该传递给哪个组件。
隐式意图:没有明确指定组件名的Intent为隐式意图。 Android系统会根据隐式意图中设置的动作(action)、类别(category)、数据(URI和数据类型)找到最合适的组件来处理这个意图。
MainActivity.java
- package cn.android.intent;
- import java.util.Date;
- import android.app.Activity;
- import android.content.Intent;
- import android.os.Bundle;
- import android.view.KeyEvent;
- import android.view.View;
- import android.widget.TextView;
- public class NewActivity extends Activity {
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- // TODO Auto-generated method stub
- super.onCreate(savedInstanceState);
- setContentView(R.layout.other);
- Intent intent = getIntent();
- //Log.i("NewActivity", intent.getData().getPath());
- String title = intent.getStringExtra("title");
- double since = intent.getDoubleExtra("since", 1995.5);
- TextView textView = (TextView) this.findViewById(R.id.textView);
- textView.setText("语言:" + title + ",发布时间:" + since + "。");
- }
- public void closeActivity(View v) {
- Intent intent = new Intent();
- intent.putExtra("result", new Date().toString());
- setResult(501, intent);
- this.finish();
- }
- @Override
- public boolean onKeyDown(int keyCode, KeyEvent event) {
- if (keyCode == KeyEvent.KEYCODE_BACK) {
- closeActivity(null);
- }
- return true;
- }
- }
NewActivity.java
- package cn.android.intent;
- import java.util.Date;
- import android.app.Activity;
- import android.content.Intent;
- import android.os.Bundle;
- import android.view.KeyEvent;
- import android.view.View;
- import android.widget.TextView;
- public class NewActivity extends Activity {
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- // TODO Auto-generated method stub
- super.onCreate(savedInstanceState);
- setContentView(R.layout.other);
- Intent intent = getIntent();
- //Log.i("NewActivity", intent.getData().getPath());
- String title = intent.getStringExtra("title");
- double since = intent.getDoubleExtra("since", 1995.5);
- TextView textView = (TextView) this.findViewById(R.id.textView);
- textView.setText("语言:" + title + ",发布时间:" + since + "。");
- }
- public void closeActivity(View v) {
- Intent intent = new Intent();
- intent.putExtra("result", new Date().toString());
- setResult(501, intent);
- this.finish();
- }
- @Override
- public boolean onKeyDown(int keyCode, KeyEvent event) {
- if (keyCode == KeyEvent.KEYCODE_BACK) {
- closeActivity(null);
- }
- return true;
- }
- }
main.xml
- <?xml version="1.0" encoding="utf-8"?>
- <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:layout_width="fill_parent"
- android:layout_height="fill_parent">
- <TextView
- android:layout_width="fill_parent"
- android:layout_height="wrap_content"
- android:text="@string/hello"
- android:id="@+id/textView" />
- <LinearLayout
- android:layout_width="fill_parent"
- android:layout_height="fill_parent"
- android:orientation="horizontal"
- android:gravity="center_horizontal"
- android:layout_below="@id/textView">
- <Button
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:text="@string/button_display"
- android:id="@+id/buttonDisplay"
- android:onClick="openActivityDisplay" />
- <Button
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:text="@string/button_hidden"
- android:onClick="openActivityHidden" />
- </LinearLayout>
- </RelativeLayout>
other.xml
- <?xml version="1.0" encoding="utf-8"?>
- <TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:layout_width="fill_parent"
- android:layout_height="fill_parent">
- <TableRow>
- <TextView
- android:layout_width="fill_parent"
- android:layout_height="wrap_content"
- android:text="@string/newActivity"
- android:id="@+id/textView" />
- <Button
- android:layout_width="wrap_content"
- android:layout_height="wrap_content"
- android:text="@string/button_close"
- android:onClick="closeActivity" />
- </TableRow>
- </TableLayout>
AndroidManifest.xml
- <?xml version="1.0" encoding="utf-8"?>
- <manifest xmlns:android="http://schemas.android.com/apk/res/android"
- package="cn.android.intent"
- android:versionCode="1"
- android:versionName="1.0" >
- <uses-sdk android:minSdkVersion="8" />
- <application
- android:icon="@drawable/ic_launcher"
- android:label="@string/app_name" >
- <activity
- android:label="@string/app_name"
- android:name=".MainActivity" >
- <intent-filter >
- <action android:name="android.intent.action.MAIN" />
- <category android:name="android.intent.category.LAUNCHER" />
- </intent-filter>
- </activity>
- <activity android:name=".NewActivity" android:label="@string/newActivity">
- <intent-filter>
- <action android:name="cn.java.action.android" />
- <action android:name="cn.java.action.windowsphone" />
- <category android:name="android.intent.category.DEFAULT" />
- <category android:name="cn.java.category.intent" />
- <category android:name="cn.java.category.action" />
- <data android:scheme="intent" android:host="www.android.com" />
- <data android:mimeType="image/*" />
- </intent-filter>
- </activity>
- </application>
- </manifest>
strings.xml
- <?xml version="1.0" encoding="utf-8"?>
- <resources>
- <string name="hello">Hello World, MainActivity!</string>
- <string name="newActivity">New Activity!</string>
- <string name="app_name">Android意图</string>
- <string name="button_display">打开显示意图</string>
- <string name="button_hidden">打开隐式意图</string>
- <string name="button_close">关闭窗口</string>
- </resources>
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