android初级三 -button响应与intent
一、Button 事件处理
1.创建新工程
2.修改main.xml 布局，添加一个TextView 和一个Button
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:orientation="vertical" 4 android:layout_width="fill_parent" 5 android:layout_height="fill_parent" 6 > 7 <TextView 8 android:id="@+id/show_TextView" 9 android:layout_width="fill_parent" 10 android:layout_height="wrap_content" 11 android:text="@string/hello" 12 /> 13 <Button 14 android:id="@+id/Click_Button" 15 android:layout_width="wrap_content" 16 android:layout_height="wrap_content" 17 android:text="点击" 18 /> 19 </LinearLayout>
3. 在mainActivity.java 中findViewByID()获取TextView 和Button 资源
1 show= (TextView)findViewById(R.id.show_TextView); 2 press=(Button)findViewById(R.id.Click_Button);
4.给Button 添加事件监听器Button.OnClickListener()
1 press.setOnClickListener(new Button.OnClickListener(){ 2 @Override 3 public void onClick(View v) { 4 // TODO Auto-generated method stub 5 show.setText("Hi , Google Android!"); 6 } 7 });
二、手机页面的转换
需要定义二个xml 布局文，一个为mylayout，另一个为main
其JAVA代码如下：
1 import android.app.Activity;/* import 相关class */ 2 import android.os.Bundle; 3 import android.view.View; 4 import android.widget.Button; 5 public class Ex8_UI extends Activity { 6 /** Called when the activity is first created. */ 7 @Override 8 public void onCreate(Bundle savedInstanceState) { 9 super.onCreate(savedInstanceState); 10 /* 载入main.xml Layout */ 11 setContentView(R.layout.main);// 默认启动布局 12 /* 以findViewById()取得Button 对象，并添加onClickListener */ 13 Button b1 = (Button) findViewById(R.id.button1); 14 b1.setOnClickListener(new Button.OnClickListener() { 15 public void onClick(View v) { 16 jumpToLayout2();// 调用跳转方法jumpToLayout2() 17 } 18 }); 19 } /* method jumpToLayout2：将 20 layout 由 21 main.xml 切 22 换 23 成 24 mylayout.xml */ 25 public void jumpToLayout2() { 26 /* 将layout 改成mylayout.xml */ 27 setContentView(R.layout.mylayout); 28 /* 以findViewById()取得Button 对象，并添加onClickListener */ 29 Button b2 = (Button) findViewById(R.id.button2); 30 b2.setOnClickListener(new Button.OnClickListener() { 31 public void onClick(View v) { 32 jumpToLayout1();// 调用跳转方法jumpToLayout1() 33 } 34 }); 35 } /* method jumpToLayout1：将 36 layout 由 37 mylayout.xml 切 38 换 39 成main.xml */ 40 public void jumpToLayout1() { 41 /* 将layout 改成main.xml */ 42 setContentView(R.layout.main); 43 /* 以findViewById()取得Button 对象，并添加onClickListener */ 44 Button b1 = (Button) findViewById(R.id.button1); 45 b1.setOnClickListener(new Button.OnClickListener() { 46 public void onClick(View v) { 47 jumpToLayout2();// 调用跳转方法jumpToLayout2() 48 } 49 }); 50 } 51 }
三、调用加一个activity
Intent 对象的使用
① 新建工程
② 在string.xml 中添加两个字符串
1 <?xml version="1.0" encoding="utf-8"?> 2 <resources> 3 <string name="hello">Hello World, Ex9_UI!</string> 4 <string name="app_name">Ex9_UI</string> 5 <string name="act1">This is Activity 1!</string> 6 <string name="act2">This is Activity 2!</string> 7 </resources>
③ 新建color.xml 存放颜色值
1 <?xml version="1.0" encoding="utf-8"?> 2 <resources> 3 <color name="black">#000000</color> 4 <color name="white">#FFFFFFFF</color> 5 </resources>
④ 修改main.xml 布局，添加一个TextView 和一个Button
1 <?xml version="1.0" encoding="utf-8"?> 2 <AbsoluteLayout 3 android:layout_width="fill_parent" 4 android:layout_height="fill_parent" 5 android:background="@color/black" 6 xmlns:android="http://schemas.android.com/apk/res/android" 7 > < 8 TextView 9 android:id="@+id/text1" 10 android:textSize="24sp" 11 android:layout_width="186px" 12 android:layout_height="29px" 13 android:layout_x="70px" 14 android:layout_y="32px" 15 android:text="@string/act1" 16 ></TextView> 17 <Button 18 android:id="@+id/button1" 19 android:layout_width="118px" 20 android:layout_height="wrap_content"
android:layout_x="100px"
android:layout_y="82px"
android:text="Go to Activity2"
></Button>
</AbsoluteLayout>
⑤ 新建一个secondlayout.xml 布局，并添加一个TextView 和一个Button
1 <?xml version="1.0" encoding="utf-8"?> 2 <AbsoluteLayout 3 android:layout_width="fill_parent" 4 android:layout_height="fill_parent" 5 android:background="@color/white" 6 xmlns:android="http://schemas.android.com/apk/res/android" 7 > < 8 TextView 9 android:id="@+id/text2" 10 android:textSize="24sp" 11 android:layout_width="186px" 12 android:layout_height="29px" 13 android:layout_x="70px" 14 android:layout_y="32px" 15 android:textColor="@color/black" 16 android:text="@string/act2" 17 ></TextView> 18 <Button 19 android:id="@+id/button2" 20 android:layout_width="118px" 21 android:layout_height="wrap_content" 22 android:layout_x="100px" 23 android:layout_y="82px" 24 android:text="Go to Activity1" 25 ></Button> 26 </AbsoluteLayout>
⑥ 新建SecondActivity.java 文件，添加内容
1 package zyf.Ex9_UI; 2 import android.app.Activity; 3 import android.content.Intent; 4 import android.os.Bundle; 5 import android.view.View; 6 import android.widget.Button; 7 public class SecondActivity extends Activity { 8 /** Called when the activity is first created. */ 9 @Override 10 public void onCreate(Bundle savedInstanceState) { 11 super.onCreate(savedInstanceState); 12 /* 载入mylayout.xml Layout */ 13 setContentView(R.layout.mylayout); 14 /* 以findViewById()取得Button 对象，并添加onClickListener */ 15 Button b2 = (Button) findViewById(R.id.button2); 16 b2.setOnClickListener(new Button.OnClickListener() { 17 public void onClick(View v) { 18 /* new 一个Intent 对象，并指定要启动的class */ 19 Intent intent = new Intent(); 20 intent.setClass(SecondActivity.this, Ex9_UI.class); 21 /* 调用一个新的Activity */ 22 startActivity(intent); 23 /* 关闭原本的Activity */ 24 SecondActivity.this.finish(); 25 } 26 }); 27 } 28 }
⑦ 修改mainActivity.java,添加代码
1 package zyf.Ex9_UI; 2 import android.app.Activity; 3 import android.content.Intent; 4 import android.os.Bundle; 5 import android.view.View; 6 import android.widget.Button; 7 public class Ex9_UI extends Activity { 8 /** Called when the activity is first created. */ 9 @Override 10 public void onCreate(Bundle savedInstanceState) { 11 super.onCreate(savedInstanceState); 12 /* 载入main.xml Layout */ 13 setContentView(R.layout.main); 14 /* 以findViewById()取得Button 对象，并添加onClickListener */ 15 Button b1 = (Button) findViewById(R.id.button1); 16 b1.setOnClickListener(new Button.OnClickListener() { 17 public void onClick(View v) { 18 /* new 一个Intent 对象，并指定要启动的class */ 19 Intent intent = new Intent(); 20 intent.setClass(Ex9_UI.this, SecondActivity.class); 21 /* 调用一个新的Activity */ 22 startActivity(intent); 23 /* 关闭原本的Activity */ 24 Ex9_UI.this.finish(); 25 } 26 }); 27 } 28 }
⑧ 在AndroidManifest.xml 文件中添加SecondActivity
1 <?xml version="1.0" encoding="utf-8"?> 2 <manifest xmlns:android="http://schemas.android.com/apk/res/android" 3 package="zyf.Ex9_UI" 4 android:versionCode="1" 5 android:versionName="1.0"> 6 <application android:icon="@drawable/icon" 7 android:label="@string/app_name" > 8 <activity android:name=".Ex9_UI" 9 android:label="@string/app_name" > 10 <intent-filter> 11 <action android:name="android.intent.action.MAIN" /> 12 <category android:name="android.intent.category.LAUNCHER" /> 13 </intent-filter> 14 </activity> 15 <activity android:name="SecondActivity"></activity> 16 </application> 17 <uses-sdk android:minSdkVersion="2" /> 18 </manifest>
四、不同Activity之间数据传递。
在AndroidManifest.xml 添加Activity 定义
1 <?xml version="1.0" encoding="utf-8"?> 2 <manifest xmlns:android="http://schemas.android.com/apk/res/android" 3 package="zyf.Ex10_UI" 4 android:versionCode="1" 5 android:versionName="1.0"> 6 <application android:icon="@drawable/icon" 7 android:label="@string/app_name" > 8 <activity android:name=".Ex10_UI" 9 android:label="@string/app_name" > 10 <intent-filter> 11 <action android:name="android.intent.action.MAIN" /> 12 <category android:name="android.intent.category.LAUNCHER" /> 13 </intent-filter> 14 </activity> 15 <activity android:name="BMIActivity"></activity> 16 </application> 17 <uses-sdk android:minSdkVersion="2" /> 18 </manifest>
修改BMIActivity.java 内容
1 package zyf.Ex10_UI; 2 /* import 相关class */ 3 import java.text.DecimalFormat; 4 import java.text.NumberFormat; 5 import android.app.Activity; 6 import android.os.Bundle; 7 import android.widget.TextView; 8 public class BMIActivity extends Activity { 9 /** Called when the activity is first created. */ 10 @Override 11 public void onCreate(Bundle savedInstanceState) { 12 super.onCreate(savedInstanceState); 13 /* 加载main.xml Layout */ 14 setContentView(R.layout.mylayout); 15 /* 取得Intent 中的Bundle 对象*/ 16 Bundle bunde = this.getIntent().getExtras(); 17 /* 取得Bundle 对象中的数据*/ 18 String sex = bunde.getString("sex"); 19 double height = bunde.getDouble("height"); 20 /* 判断性别*/ 21 String sexText = ""; 22 if (sex.equals("M")) { 23 sexText = "男性"; 24 } else { 25 sexText = "女性"; 26 } /* 取 27 得 28 标 29 准 30 体 31 重 32 */ 33 String weight = this.getWeight(sex, height); 34 /* 设置输出文字*/ 35 TextView tv1 = (TextView) findViewById(R.id.text1); 36 tv1.setText("你是一位" + sexText + "\n你的身高是" + height + 37 "厘米\n你的标准体重是"+ weight + "公斤"); 38 } 39 /* 四舍五入的method */ 40 private String format(double num) { 41 NumberFormat formatter = new DecimalFormat("0.00"); 42 String s = formatter.format(num); 43 return s; 44 }
/* 以findViewById()取得Button 对象，并添加onClickListener */
private String getWeight(String sex, double height) {
String weight = "";
if (sex.equals("M")) {
weight = format((height - 80) * 0.7);
} else {
weight = format((height - 70) * 0.6);
} return weight;
}
}
修改mainActivity.java 内容
1 import 相关class */ 2 import android.app.Activity; 3 import android.content.Intent; 4 import android.os.Bundle; 5 import android.view.View; 6 import android.widget.Button; 7 import android.widget.EditText; 8 import android.widget.RadioButton; 9 public class Ex10_UI extends Activity { 10 /** Called when the activity is first created. */ 11 @Override 12 public void onCreate(Bundle savedInstanceState) { 13 super.onCreate(savedInstanceState); 14 /* 载入main.xml Layout */ 15 setContentView(R.layout.main); 16 /* 以findViewById()取得Button 对象，并添加onClickListener */ 17 Button ok = (Button) findViewById(R.id.button_OK); 18 ok.setOnClickListener(new Button.OnClickListener() { 19 public void onClick(View v) { 20 /* 取得输入的身高*/ 21 EditText et = (EditText) findViewById(R.id.height_Edit); 22 double height = Double.parseDouble(et.getText().toString()); 23 /* 取得选择的性别*/ 24 String sex = ""; 25 RadioButton rb1 = (RadioButton) findViewById(R.id.Sex_Man); 26 if (rb1.isChecked()) { 27 sex = "M"; 28 } else { 29 sex = "F"; 30 } /* new 一 31 个 32 Intent 对 33 象 34 ， 35 并 36 指 37 定 38 class */ 39 Intent intent = new Intent(); 40 intent.setClass(Ex10_UI.this, BMIActivity.class); 41 /* new 一个Bundle对象，并将要传递的数据传入*/ 42 Bundle bundle = new Bundle(); 43 bundle.putDouble("height", height); 44 bundle.putString("sex", sex); 45 /* 将Bundle 对象assign 给Intent */ 46 intent.putExtras(bundle); 47 /* 调用Activity EX03_10_1 */ 48 startActivity(intent); 49 } 50 }); 51 } 52 }
五、返回数据到前一个Activity
1 @ 2 Override 3 protected void onActivityResult(int requestCode, int resultCode, 4 Intent data) { 5 // TODO Auto-generated method stub 6 super.onActivityResult(requestCode, resultCode, data); 7 switch (resultCode) { 8 case RESULT_OK: 9 /* 取得来自Activity2 的数据，并显示于画面上*/ 10 Bundle bunde = data.getExtras(); 11 String sex = bunde.getString("sex"); 12 double height = bunde.getDouble("height"); 13 edit_height.setText("" + height); 14 if (sex.equals("M")) { 15 radiobutton_Man.setChecked(true); 16 } else { 17 radiobutton_Woman.setChecked(true); 18 } break break; 19 default: 20 break; 21 } 22 } 23 }
1 Intent intent = new Intent(); 2 intent.setClass(Ex11_UI_A.this, BMIActivity.class); 3 /* new 一个Bundle对象，并将要传递的数据传入*/ 4 Bundle bundle = new Bundle(); 5 bundle.putDouble("height", height); 6 bundle.putString("sex", sex); 7 /* 将Bundle 对象assign 给Intent */ 8 intent.putExtras(bundle); 9 /* 调用Activity EX03_10_1 */ 10 startActivityForResult(intent, my_requestCode);
1 Button b1 = (Button) findViewById(R.id.button_back); 2 b1.setOnClickListener(new Button.OnClickListener() { 3 @Override 4 public void onClick(View v) { 5 // TODO Auto-generated method stub 6 /* 返回result 回上一个activity */ 7 BMIActivity.this.setResult(RESULT_OK, intent); 8 /* 结束这个activity */ 9 BMIActivity.this.finish(); 10 } 11 });
六、返回数据到前一个Activity
Toast 显示一个TextView
1 package zyf.EX_Ctrl_3_B; 2 import android.app.Activity; 3 import android.os.Bundle; 4 import android.widget.TextView; 5 import android.widget.Toast; 6 public class EX_Ctrl_3_B extends Activity { 7 /** Called when the activity is first created. */ 8 @Override 9 public void onCreate(Bundle savedInstanceState) { 10 super.onCreate(savedInstanceState); 11 /* 设置主屏布局*/ 12 setContentView(R.layout.main); 13 /* 创建新Toast对象*/ 14 Toast showImageToast = new Toast(this); 15 /*新建TextView对象*/ 16 TextView text=new TextView(this); 17 /*设置TextView内容*/ 18 text.setText("显示在Toast中的TextView"); 19 /* 设置Toast上的View--(TextView) */ 20 showImageToast.setView(text); 21 /* 设置Toast显示时间*/ 22 showImageToast.setDuration(Toast.LENGTH_LONG); 23 /* 显示Toast */ 24 showImageToast.show(); 25 } 26 } 27 28 29 30 package zyf.EX_Ctrl_3_B; 31 import android.app.Activity; 32 import android.os.Bundle; 33 import android.view.View; 34 import android.widget.Button; 35 import android.widget.Toast; 36 public class EX_Ctrl_3_B extends Activity { 37 /** Called when the activity is first created. */ 38 @Override 39 public void onCreate(Bundle savedInstanceState) { 40 super.onCreate(savedInstanceState); 41 /* 设置主屏布局*/ 42 setContentView(R.layout.main); 43 /* 创建新Toast对象*/ 44 Toast showImageToast = new Toast(this); 45 // /*新建Button对象*/ 46 Button button = new Button(this); 47 button.setText("OK"); 48 /* 设置Toast上的View--(Button) */ 49 showImageToast.setView(button); 50 /* 设置Toast显示时间*/ 51 showImageToast.setDuration(Toast.LENGTH_LONG); 52 /* 显示Toast */ 53 showImageToast.show(); 54 } 55 }
七 AlertDialog.Builder提示对话框
1 package zyf.EX_Ctrl_3_B; 2 import android.app.Activity; 3 import android.app.AlertDialog; 4 import android.os.Bundle; 5 public class EX_Ctrl_3_B extends Activity { 6 /** Called when the activity is first created. */ 7 @Override 8 public void onCreate(Bundle savedInstanceState) { 9 super.onCreate(savedInstanceState); 10 /* 设置主屏布局*/ 11 setContentView(R.layout.main); 12 /*新建一个AlertDialog.Builder对象*/ 13 AlertDialog.Builder my_ADialog =new AlertDialog.Builder(this); 14 /*设置标题*/ 15 my_ADialog.setTitle("Android 提示"); 16 /*设置显示消息*/ 17 my_ADialog.setMessage("AlertDialog.Builder提示对话框消息!!"); 18 /*显示*/ 19 my_ADialog.show(); 20 } 21 }
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