点击事件的必备条件:实现OnClickListener
接口,重写 v)
方法
以拨号简单案例为例,如下图效果:
逻辑流程:
获取点击对象,获取数据
给对象设置监听类
实现
OnClickListener
接口,重写onClick(View v)
方法
onClick(View v)
逻辑:
获取输入内容:使用
EditText
对象的getText()
方法,该方法返回值为Editable
,需要用toString()
转换成String
类型判断输入是否为空,
TextUtils.isEmpty(str)
方法判断字符串str
是否为空为空则提示
号码不能为空
,使用Toast.makeText(MainActivity.this, "号码不能为空", Toast.LENGTH_SHORT).show();
,Toast makeText (Context context, CharSequence text, int duration)
返回值为Toast,参数列表(Context对象,提示内容,显示时长)
如果不为空,
new
一个Intent
对象,使用Intent
对象的setAction(String action)
方法设置动作,使用Intent
对象的setData(Uri uriData)
方法设置数据。startActivity(Intent intent)
方法启动Activity。
注:应该在程序清单文件AndroidManifest.xml中添加<uses-permission android:name="android.permission.CALL_PHONE"/>
,拨打电话时,美国紧急电话不会直接拨打
三种方法:第四种不推荐,前三种酌情使用
1. 内部实现类
布局文件:activity_main.xml
<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" tools:context="${relativePackage}.${activityClass}" > <EditText android:id="@+id/editText1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:focusable="true" android:focusableInTouchMode="true" android:hint="在此输入电话号码"> </EditText> <Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@+id/editText1" android:layout_marginTop="14dp" android:text="拨打此号码" /> <Button android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_below="@+id/button1" android:text="Button2" /> <Button android:id="@+id/button3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_below="@+id/button2" android:text="Button3" /></RelativeLayout>
MainActivity.java
package com.example.onclick1; import android.app.Activity; import android.content.Intent; import android.net.Uri; import android.os.Bundle; import android.os.storage.OnObbStateChangeListener; import android.text.TextUtils; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; public class MainActivity extends Activity { private EditText editText; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); editText = (EditText) findViewById(R.id.editText1); Button button1 = (Button) findViewById(R.id.button1); Button button2 = (Button) findViewById(R.id.button2); Button button3 = (Button) findViewById(R.id.button3); //设置监听类 button1.setOnClickListener(new MyOnClickListener()); button2.setOnClickListener(new MyOnClickListener()); button3.setOnClickListener(new MyOnClickListener()); } private class MyOnClickListener implements OnClickListener{ @Override public void onClick(View v) { int i = v.getId(); switch (i) { case R.id.button1: String number = editText.getText().toString(); if (TextUtils.isEmpty(number)) { Toast.makeText(MainActivity.this, "号码不能为空", Toast.LENGTH_SHORT).show(); }else { Intent intent = new Intent(); intent.setAction(intent.ACTION_CALL); Uri data = Uri.parse("tel:"+number); intent.setData(data); startActivity(intent); } break; case R.id.button2: Toast.makeText(MainActivity.this, "你点击了Button2", Toast.LENGTH_SHORT).show(); break; case R.id.button3: Toast.makeText(MainActivity.this, "你点击了Button3", Toast.LENGTH_SHORT).show(); break; } } } }
2. 内部匿名类
MainActivity.java
package com.example.onclick1; import android.app.Activity; import android.content.Intent; import android.net.Uri; import android.os.Bundle; import android.os.storage.OnObbStateChangeListener; import android.text.TextUtils; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; public class MainActivity extends Activity { private EditText editText; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); editText = (EditText) findViewById(R.id.editText1); Button button1 = (Button) findViewById(R.id.button1); Button button2 = (Button) findViewById(R.id.button2); Button button3 = (Button) findViewById(R.id.button3); //设置监听类 button1.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { String number = editText.getText().toString(); if(TextUtils.isEmpty(number)){ Toast.makeText(MainActivity.this, "[内部匿名类]号码不能为空", Toast.LENGTH_SHORT).show(); }else{ Intent intent = new Intent(); intent.setAction(intent.ACTION_CALL); intent.setData(Uri.parse("tel:"+number)); startActivity(intent); } } }); button2.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { Toast.makeText(MainActivity.this, "[内部匿名类]你点击了Button2", Toast.LENGTH_SHORT).show(); } }); button3.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { Toast.makeText(MainActivity.this, "[内部匿名类]你又点击了button3", Toast.LENGTH_SHORT).show(); } }); } }
3. Activity实现OnClickLitener
MainActivity.java
package com.example.onclick1; import android.app.Activity; import android.content.Intent; import android.net.Uri; import android.os.Bundle; import android.os.storage.OnObbStateChangeListener; import android.text.TextUtils; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; public class MainActivity extends Activity implements OnClickListener{ private EditText editText; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); editText = (EditText) findViewById(R.id.editText1); Button button1 = (Button) findViewById(R.id.button1); Button button2 = (Button) findViewById(R.id.button2); Button button3 = (Button) findViewById(R.id.button3); //设置监听类 button1.setOnClickListener(this); button2.setOnClickListener(this); button3.setOnClickListener(this); } @Override public void onClick(View v) { int id = v.getId(); switch (id) { case R.id.button1: String number = editText.getText().toString(); if (TextUtils.isEmpty(number)) { Toast.makeText(this, "[Activity实现类]号码不能为空", Toast.LENGTH_SHORT).show(); }else { Intent intent = new Intent(); intent.setAction(intent.ACTION_CALL); intent.setData(Uri.parse("tel:"+number)); startActivity(intent); } break; case R.id.button2: Toast.makeText(this, "[Activity实现类]你点击了Button2", Toast.LENGTH_SHORT).show(); break; case R.id.button3: Toast.makeText(this, "[Activity实现类]你点击了Button3", Toast.LENGTH_SHORT).show(); break; } } }
4. 结合layout文件声明方法
activity_main.xml
<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" tools:context="${relativePackage}.${activityClass}" > <EditText android:id="@+id/editText1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:focusable="true" android:focusableInTouchMode="true" android:hint="在此输入电话号码"> </EditText> <Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@+id/editText1" android:layout_marginTop="14dp" android:onClick="button" android:text="拨打此号码" /> <Button android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_below="@+id/button1" android:onClick="button" android:text="Button2" /> <Button android:id="@+id/button3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_below="@+id/button2" android:onClick="button" android:text="Button3" /> </RelativeLayout>
MainActivity.java
package com.example.onclick1; import android.app.Activity; import android.content.Intent; import android.net.Uri; import android.os.Bundle; import android.os.storage.OnObbStateChangeListener; import android.text.TextUtils; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.EditText; import android.widget.Toast; public class MainActivity extends Activity{ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } public void button(View v) { EditText editText = (EditText) findViewById(R.id.editText1); switch (v.getId()) { case R.id.button1: String number = editText.getText().toString(); if (TextUtils.isEmpty(number)) { Toast.makeText(this, "[布局文件中Button的android:onClick属性]号码不能为空", Toast.LENGTH_SHORT).show(); }else { Intent intent = new Intent(); intent.setAction(intent.ACTION_CALL); intent.setData(Uri.parse("tel:"+number)); startActivity(intent); } break; case R.id.button2: Toast.makeText(this, "[布局文件中Button的android:onClick属性]你点击了Button2", Toast.LENGTH_SHORT).show(); break; case R.id.button3: Toast.makeText(this, "[布局文件中Button的android:onClick属性]你点击了Button3", Toast.LENGTH_SHORT).show(); break; } } }