代码实现Selector按钮点击效果

来源：互联网发布：车贷月供算法编辑：程序博客网时间：2024/05/18 03:42

文章出处：http://www.devdiv.com/Android-_Android_%E4%BB%A3%E7%A0%81%E5%AE%9E%E7%8E%B0StateListDrawable-thread-92751-1-1.html

用途：动态设置Button、ImageView等组件在不同状态下的背景/前景显示效果。扩展下的话可以前景/背景的显示效果可以使用网络图片。
优点：灵活，减少xml的编写。

参考：
[AndroidOpenSource]frameworksasecorejavaandroidviewview.xml
[AndroidOpenSource]frameworksasecoreesesvaluespublic.xml
代码如下：

        /** 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;        }

示例代码：

                Button btnNormal = (Button) findViewById(R.id.btnSampleNormal);                btnNormal.setBackgroundDrawable(newSelector(this, R.drawable.btn_normal, R.drawable.btn_selected,                                R.drawable.btn_selected, R.drawable.btn_unable));                Button btnUnable = (Button) findViewById(R.id.btnSampleUnable);                btnUnable.setBackgroundDrawable(newSelector(this, R.drawable.btn_normal, R.drawable.btn_selected,                                R.drawable.btn_selected, R.drawable.btn_unable));                btnUnable.setEnabled(false);                btnUnable.setOnClickListener(this);