Android 开发 怎样使当前界面的背景透明

核心提示：activity的代码如下：view plaincopy to clipboardprint?1. public class StartActivity extends Activity {2. public void onCreate(Bundle savedInstanceState){3. super.onCre

activity的代码如下：

view plaincopy to clipboardprint?

1. public class StartActivity extends Activity {

2. public void onCreate(Bundle savedInstanceState){

3. super.onCreate(savedInstanceState);

4. showDialog(1);

5. }

6.

7. protected Dialog onCreateDialog(int id) {

8. LayoutInflater factory = LayoutInflater.from(this);

9. View tv = factory.inflate(R.layout.login,null);

10. return new AlertDialog.Builder(this).setTitle("请输入验证码：").setPositiveButton("确定",new DialogInterface.OnClickListener() {

11. public void onClick(DialogInterface dialog, int which) {

12. Intent i = new Intent(StartActivity.this,MainTab.class);

13. StartActivity.this.startActivity(i);

14. finish();

15. }

16. }).setView(tv).create();

17. }

18. }

public class StartActivity extends Activity { public void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); showDialog(1); } protected Dialog onCreateDialog(int id) { LayoutInflater factory = LayoutInflater.from(this); View tv = factory.inflate(R.layout.login,null); return new AlertDialog.Builder(this).setTitle("请输入验证码：").setPositiveButton("确定",new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { Intent i = new Intent(StartActivity.this,MainTab.class); StartActivity.this.startActivity(i); finish(); } }).setView(tv).create(); } }

很简单的代码，就是显示一个对话框

如果直接运行，会看到背景为黑色的，如果想要透明背景的话，需要对当前的activity加上一个主题，即透明主题，修改AndroidManifest.xml

中的activity的定义：

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　 1.　　　　　　  <activity 
　 2. android:name=".StartActivity"