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
