Android(安卓)四大核心组件之Activity--Intent数据传递
16lz
2022-07-22
1 Activity简单跳转,
1.1 Activity的页面样式及跳转方式：
activity_a.xml
ActivityA.java
public class ActivityA extends Activity {private Button btn_submit; //定义button局部变量 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_a); btn_submit = (Button) findViewById(R.id.btn_submit); btn_submit.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//Intent intent = new Intent(); //创建一个Intent对象//intent.setClass(ActivityA.this, ActivityB.class); //描述起点和目标/*上面两种方式可以简写成如下代码*/Intent intent = new Intent(ActivityA.this, ActivityB.class); //简写形式intent.putExtra("txt", "苏州科技大学"); //设置跳转值的传递startActivities(intent); //开始跳转}}); } protected void startActivities(Intent intent) {// TODO Auto-generated method stub super.startActivity(intent); }activity_b.xml
public class ActivityB extends Activity {private TextView tvOut;@Overrideprotected void onCreate(Bundle savedInstanceState) { //重写onCreate()方法super.onCreate(savedInstanceState);setContentView(R.layout.activity_b); //绑定布局tvOut = (TextView) findViewById(R.id.tvOut);tvOut.setText(getIntent().getStringExtra("txt"));}}在startActivities()方法调用时，需要先实现该方法。1.2 实现关闭功能
activity_b.xml添加关闭按钮
public class ActivityB extends Activity {private Button btnClose;@Overrideprotected void onCreate(Bundle savedInstanceState) { //重写onCreate()方法super.onCreate(savedInstanceState);setContentView(R.layout.activity_b); //绑定布局btnClose = (Button) findViewById(R.id.btnClose);btnClose.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {finish();}});}}Activity.onDestory():系统销毁了这个Activity的实例在内存中占据的空间。在Activity的生命周期中，onDestory()方法是他生命的最后一步，资源空间等就被回收了。当重新进入此Activity的时候，必须重新创建，执行onCreate()方法。
System.exit(0):调用System.exit(0)时，杀死了整个进程，这时候活动所占的资源也会被释放。
2 使用Bundle传递数据
ActivityA.java
public class ActivityA extends Activity {private Button btn_submit; //定义button局部变量 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_a); btn_submit = (Button) findViewById(R.id.btn_submit); btn_submit.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//Intent intent = new Intent(); //创建一个Intent对象//intent.setClass(ActivityA.this, ActivityB.class); //描述起点和目标/*上面两种方式可以简写成如下代码*/Intent intent = new Intent(ActivityA.this, ActivityB.class); //简写形式//intent.putExtra("txt", "苏州科技大学"); //设置跳转值的传递//方式二：使用bundle方式传递数据Bundle data = new Bundle();data.putString("txt", "苏州科技大学");intent.putExtras(data);startActivities(intent); //开始跳转}}); }ActivityB.java
public class ActivityB extends Activity {private TextView tvOut;private Button btnClose;@Overrideprotected void onCreate(Bundle savedInstanceState) { //重写onCreate()方法super.onCreate(savedInstanceState);setContentView(R.layout.activity_b); //绑定布局tvOut = (TextView) findViewById(R.id.tvOut);//tvOut.setText(getIntent().getStringExtra("txt"));//方式二：使用bundle方式接收数据//得到数据Bundle data = getIntent().getExtras();String txt = data.getString("txt");tvOut.setText(txt);btnClose = (Button) findViewById(R.id.btnClose);btnClose.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {finish();}});}}3 取得传回的数据
ActivityB.java
public class ActivityB extends Activity {private TextView tvOut;private Button btnClose;@Overrideprotected void onCreate(Bundle savedInstanceState) { //重写onCreate()方法super.onCreate(savedInstanceState);setContentView(R.layout.activity_b); //绑定布局tvOut = (TextView) findViewById(R.id.tvOut);//tvOut.setText(getIntent().getStringExtra("txt"));//方式二：使用bundle方式接收数据//得到数据Bundle data = getIntent().getExtras();String txt = data.getString("txt");tvOut.setText(txt);btnClose = (Button) findViewById(R.id.btnClose);btnClose.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {Intent intent = new Intent();intent.putExtra("result", "计算机科学与技术");setResult(0, intent); //指定返回值finish();}});}}activity_a.xml
ActivityA.java
public class ActivityA extends Activity {private Button btn_submit; //定义button局部变量private TextView tvOut; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_a); tvOut = (TextView) findViewById(R.id.tvOut); btn_submit = (Button) findViewById(R.id.btn_submit); btn_submit.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//Intent intent = new Intent(); //创建一个Intent对象//intent.setClass(ActivityA.this, ActivityB.class); //描述起点和目标/*上面两种方式可以简写成如下代码*/Intent intent = new Intent(ActivityA.this, ActivityB.class); //简写形式//intent.putExtra("txt", "苏州科技大学"); //设置跳转值的传递//方式二：使用bundle方式传递数据Bundle data = new Bundle();data.putString("txt", "苏州科技大学");intent.putExtras(data);//startActivities(intent); //开始跳转startActivityForResult(intent, 0);}}); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { String result = data.getStringExtra("result"); tvOut.setText(result); super.onActivityResult(requestCode, resultCode, data); }更多相关文章
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