3.6 响应系统设置的事件(Configuration类)

本节引言：

1.Configuration给我们提供的方法列表

2.写个简单例子测试下：

运行截图：

代码实现：

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView txtResult = (TextView) findViewById(R.id.txtResult);
        StringBuffer status = new StringBuffer();
        //①获取系统的Configuration对象
        Configuration cfg = getResources().getConfiguration();
        //②想查什么查什么
        status.append("densityDpi:" + cfg.densityDpi + "\n");
        status.append("fontScale:" + cfg.fontScale + "\n");
        status.append("hardKeyboardHidden:" + cfg.hardKeyboardHidden + "\n");
        status.append("keyboard:" + cfg.keyboard + "\n");
        status.append("keyboardHidden:" + cfg.keyboardHidden + "\n");
        status.append("locale:" + cfg.locale + "\n");
        status.append("mcc:" + cfg.mcc + "\n");
        status.append("mnc:" + cfg.mnc + "\n");
        status.append("navigation:" + cfg.navigation + "\n");
        status.append("navigationHidden:" + cfg.navigationHidden + "\n");
        status.append("orientation:" + cfg.orientation + "\n");
        status.append("screenHeightDp:" + cfg.screenHeightDp + "\n");
        status.append("screenWidthDp:" + cfg.screenWidthDp + "\n");
        status.append("screenLayout:" + cfg.screenLayout + "\n");
        status.append("smallestScreenWidthDp:" + cfg.densityDpi + "\n");
        status.append("touchscreen:" + cfg.densityDpi + "\n");
        status.append("uiMode:" + cfg.densityDpi + "\n");
        txtResult.setText(status.toString());
    }
}

3.重写onConfigurationChanged响应系统设置更改

代码示例：简单的一个按钮,点击后切换横竖屏,然后Toast提示

运行效果图：

实现代码：

public class MainActivity extends Activity {  
  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
          
        Button btn = (Button) findViewById(R.id.btncahange);  
        btn.setOnClickListener(new OnClickListener() {  
              
            @Override  
            public void onClick(View v) {  
                Configuration config = getResources().getConfiguration();  
                //如果是横屏的话切换成竖屏  
                if(config.orientation == Configuration.ORIENTATION_LANDSCAPE)  
                {  
                    MainActivity.this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);  
                }  
                //如果竖屏的话切换成横屏  
                if(config.orientation == Configuration.ORIENTATION_PORTRAIT)  
                {  
                    MainActivity.this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);  
                }  
            }  
        });  
    }  
      
    @Override  
    public void onConfigurationChanged(Configuration newConfig) {  
        super.onConfigurationChanged(newConfig);  
        String screen = newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE?"横屏":"竖屏";  
        Toast.makeText(MainActivity.this, "系统屏幕方向发生改变 \n 修改后的方向为" + screen, Toast.LENGTH_SHORT).show();  
    }  
}  

另外，还需要在AndroidManifest.xml添加下述内容：

本节小结：

本节给大家讲解了：Configuration类以及onConfigurationChanged响应系统设置更改，有个大概了解即可 后续用到我们再继续深入~