Activity到底是什麼怎麼用,到現在感覺心裡還是沒底的,說不太清楚,看文檔的時候發現一大堆方法,這裡我唯寫了簡單布局的切換,至於以後Activity的用法方法,我會慢慢學習的。
1、什麼是activity
Activity是一種互動的介面,一個介面可能有多個Activity組成。
2、示範activity的鍵盤及觸摸事件
下面示範的是一個當鍵盤按下布局切換,鍵盤彈出布局切換的一個效果,已經觸摸事件的掩飾Info資訊
public class ActivityTestActivity extends Activity { /** Called when the activity is first created. */private final static String TAG="myTag"; boolean flag = true;@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); }@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {if(flag){this.setContentView(R.layout.second);}else{this.setContentView(R.layout.main);}Log.i(TAG, "onkeydown");showInfo("keydown"+keyCode);return super.onKeyDown(keyCode, event);}@Overridepublic boolean onKeyUp(int keyCode, KeyEvent event) {flag = !flag;Log.i(TAG, "onkeyUp");showInfo("keyup"+keyCode);return super.onKeyUp(keyCode, event);}@Overridepublic boolean onTouchEvent(MotionEvent event) {Log.i(TAG, "onTouchEvent");showInfo("keytouch"+event.getX()+" "+event.getY());return super.onTouchEvent(event);}public void showInfo(String info){Toast.makeText(this, info, Toast.LENGTH_SHORT).show();} }3、實現一個activity中多個布局頁面的切換a、利用按鈕實現
通過給button添加事件監聽器onClickListener,是button直接的方法互相調用,從而實現兩個介面的切換。
package cn.csdn.hb;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.Button;public class Change extends Activity {public void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);Button1();}public void Button1() {setContentView(R.layout.second);Button btn2 = (Button) findViewById(R.id.button2);btn2.setOnClickListener(new Button.OnClickListener() {public void onClick(View v) {Button2();}});}public void Button2() {setContentView(R.layout.main);Button b1 = (Button) findViewById(R.id.button1);b1.setOnClickListener(new Button.OnClickListener() {public void onClick(View v) {Button1();}});}}
b、利用鍵盤或觸摸實現4、不同activity間的切換
如果想使兩個Activity切換,那麼肯定要使用我們具有橋樑作用的Intent
下面我分別寫了兩個xml檔案,每個xml中分別放置了兩個button,分別為button1和button2,在這裡就不寫了,我們將要實現的效果是當點擊第一個Activity裡面的button時切換到第2個Activity,當點擊到第2個Activity裡的button時,切換到第一個Activity。
第一個Activity:
public class ActivityTestActivity extends Activity { /** Called when the activity is first created. */private final static String TAG="myTag"; boolean flag = true;@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button bn = (Button)findViewById(R.id.button1); bn.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) { //建立啟動的Activity對應的Intent Intent intent =new Intent(ActivityTestActivity.this,SecondActivity.class); //動intent對應的Activity startActivity(intent);}}); }
第二個Activity:
package song.activity;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.widget.Button;public class SecondActivity extends Activity {@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.second); Button bn2 = (Button)findViewById(R.id.button2); bn2.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {Intent intent = new Intent(SecondActivity.this,ActivityTestActivity.class);startActivity(intent);}}); }}