Android实战--电话拨号器

今天跟着黑马视频建立一个android app--电话拨号器

首先新建一个android项目



activity_main_xml中的代码如下:

<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" >

<!-- 文本框 -->
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="请输入号码" />
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</RelativeLayout>

运行一下：



可以看到布局出现问题，文字出现重叠，简单的解决方法如下：

<LinearLayout 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"
tools:context=".MainActivity"
android:orientation="vertical"
>
<!-- 文本框 -->
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="请输入号码" />

<EditText
android:id="@+id/et_number"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>

<Button
android:id="@+id/bt_call"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="拨打"
/>
</LinearLayout>

界面如下所示：



MainActivity中添加下面的代码：

package com.wuyudong.dial;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 通过资源id获取到布局文件中的 对应的组件
Button bt = (Button) findViewById(R.id.bt_call);

// 给按钮设置监听
bt.setOnClickListener(new MyListener());
}

class MyListener implements OnClickListener {

// 当按钮被点击的时候，此方法会被调用
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
System.out.println("按钮被点击了！");
// 通过资源id获取到输入框
EditText et = (EditText) findViewById(R.id.et_number);
// 获取输入框的内容
String number = et.getText().toString().trim();
// 告诉系统我们的动作是打电话
Intent intent = new Intent();
// 设置动作
intent.setAction(Intent.ACTION_CALL);
// 设置打给谁
intent.setData(Uri.parse("tel:" + number));
//启动打电话应用,把意图告诉系统
startActivity(intent);
}
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

}

拨打电话后，出现如下异常：

05-26 19:43:02.155: D/dalvikvm(2042): Not late-enabling CheckJNI (already on)
05-26 19:43:02.775: D/gralloc_goldfish(2042): Emulator without GPU emulation detected.
05-26 19:43:22.015: I/System.out(2042): 按钮被点击了！
05-26 19:43:22.015: D/AndroidRuntime(2042): Shutting down VM
05-26 19:43:22.015: W/dalvikvm(2042): threadid=1: thread exiting with uncaught exception (group=0xb0e8d648)
05-26 19:43:22.015: E/AndroidRuntime(2042): FATAL EXCEPTION: main
05-26 19:43:22.015: E/AndroidRuntime(2042): java.lang.SecurityException: Permission Denial: starting Intent { act=android.intent.action.CALL dat=tel:xxx cmp=com.android.phone/.OutgoingCallBroadcaster } from ProcessRecord{b1362a50 2042:com.wuyudong.dial/u0a10047} (pid=2042, uid=10047) requires android.permission.CALL_PHONE
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.os.Parcel.readException(Parcel.java:1431)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.os.Parcel.readException(Parcel.java:1385)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.app.ActivityManagerProxy.startActivity(ActivityManagerNative.java:1947)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.app.Instrumentation.execStartActivity(Instrumentation.java:1419)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.app.Activity.startActivityForResult(Activity.java:3390)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.app.Activity.startActivityForResult(Activity.java:3351)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.app.Activity.startActivity(Activity.java:3587)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.app.Activity.startActivity(Activity.java:3555)
05-26 19:43:22.015: E/AndroidRuntime(2042): at com.wuyudong.dial.MainActivity$MyListener.onClick(MainActivity.java:44)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.view.View.performClick(View.java:4240)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.view.View$PerformClick.run(View.java:17721)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.os.Handler.handleCallback(Handler.java:730)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.os.Handler.dispatchMessage(Handler.java:92)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.os.Looper.loop(Looper.java:137)
05-26 19:43:22.015: E/AndroidRuntime(2042): at android.app.ActivityThread.main(ActivityThread.java:5103)
05-26 19:43:22.015: E/AndroidRuntime(2042): at java.lang.reflect.Method.invokeNative(Native Method)
05-26 19:43:22.015: E/AndroidRuntime(2042): at java.lang.reflect.Method.invoke(Method.java:525)
05-26 19:43:22.015: E/AndroidRuntime(2042): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
05-26 19:43:22.015: E/AndroidRuntime(2042): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
05-26 19:43:22.015: E/AndroidRuntime(2042): at dalvik.system.NativeStart.main(Native Method)

抛出安全异常，提示没有权限

解决办法如下：

打开 AndroidManifest.xml文件



点击Add，选择Users Permission



右边下拉单选择：android.permission.CALL_PHONE



Ctrl+S

重新运行，搞定