android的ColorStateList简单使用

优点：灵活，减少xml的编写。应用在TextView的文字时，亦避免使用了OnTouchListener。

用途：动态设置TextView、Button、ImageView等组件在不同状态下的背景/前景显示效果。

参考：

[AndroidOpenSource]\frameworks\base\core\Java\Android\view\view.xml

[AndroidOpenSource]\frameworks\base\core\res\res\values\public.xml

效果图如下：

代码如下：

 package lab.sodino.statelist;

 import android.app.Activity;
 import android.content.Context;
 import android.content.res.ColorStateList;
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.StateListDrawable;
 import android.os.Bundle;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.TextView;

 /**
  * 对TextView设置ColorStateList使其在Normal、Pressed、Focused、Unable四种状态下显示不同的颜色。
  * StateListDrawable可直接使用图片应用在相似场合。
  */
 public class ActColorStateList extends Activity implements OnClickListener {
     private TextView txtShow;

     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         txtShow = (TextView) findViewById(R.id.txtShow);
         txtShow.setText("Sodino\nNormal:0xffffffff\nPressed:0xffffff00\nFocused:0xff0000ff\nUnable:0xffff0000");
         txtShow.setTextColor(createColorStateList(0xffffffff, 0xffffff00, 0xff0000ff, 0xffff0000));
         txtShow.setOnClickListener(this);
     }

     /** 对TextView设置不同状态时其文字颜色。 */
     private ColorStateList createColorStateList(int normal, int pressed, int focused, int unable) {
         int[] colors = new int[] { pressed, focused, normal, focused, unable, normal };
         int[][] states = new int[6][];
         states[0] = new int[] { android.R.attr.state_pressed, android.R.attr.state_enabled };
         states[1] = new int[] { android.R.attr.state_enabled, android.R.attr.state_focused };
         states[2] = new int[] { android.R.attr.state_enabled };
         states[3] = new int[] { android.R.attr.state_focused };
         states[4] = new int[] { android.R.attr.state_window_focused };
         states[5] = new int[] {};
         ColorStateList colorList = new ColorStateList(states, colors);
         return colorList;
     }

     /** 设置Selector。 */
     public static StateListDrawable newSelector(Context context, int idNormal, int idPressed, int idFocused,
             int idUnable) {
         StateListDrawable bg = new StateListDrawable();
         Drawable normal = idNormal == -1 ? null : context.getResources().getDrawable(idNormal);
         Drawable pressed = idPressed == -1 ? null : context.getResources().getDrawable(idPressed);
         Drawable focused = idFocused == -1 ? null : context.getResources().getDrawable(idFocused);
         Drawable unable = idUnable == -1 ? null : context.getResources().getDrawable(idUnable);
         // View.PRESSED_ENABLED_STATE_SET
         bg.addState(new int[] { android.R.attr.state_pressed, android.R.attr.state_enabled }, pressed);
         // View.ENABLED_FOCUSED_STATE_SET
         bg.addState(new int[] { android.R.attr.state_enabled, android.R.attr.state_focused }, focused);
         // View.ENABLED_STATE_SET
         bg.addState(new int[] { android.R.attr.state_enabled }, normal);
         // View.FOCUSED_STATE_SET
         bg.addState(new int[] { android.R.attr.state_focused }, focused);
         // View.WINDOW_FOCUSED_STATE_SET
         bg.addState(new int[] { android.R.attr.state_window_focused }, unable);
         // View.EMPTY_STATE_SET
         bg.addState(new int[] {}, normal);
         return bg;
     }

     @Override
     public void onClick(View v) {
         if (v == txtShow) {
             txtShow.setEnabled(false);
         }
     }
 }