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:

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：

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