Android开发手记(7) 按钮类控件的使用
1、点击Button改变页面背景色
通过Button改变页面背景色，首先新建相应的对象，让后绑定到Layout上的元素。
1 final RelativeLayout layout = (RelativeLayout)this.findViewById(R.id.layout); 2 final Button btnRed = (Button)this.findViewById(R.id.btnRed);
然后向新建的按钮增加单机事件。
btnRed.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { layout.setBackgroundColor(Color.RED); ((Button)view).setText("Is Red"); } });
完整代码：
1 public class MainActivity extends AppCompatActivity { 2 3 @Override 4 protected void onCreate(Bundle savedInstanceState) { 5 super.onCreate(savedInstanceState); 6 this.setTitle("Button"); 7 setContentView(R.layout.activity_main); 8 9 final RelativeLayout layout = (RelativeLayout)this.findViewById(R.id.layout); 10 final Button btnRed = (Button)this.findViewById(R.id.btnRed); 11 final Button btnGreen = (Button)this.findViewById(R.id.btnGreen); 12 final Button btnBlue = (Button)this.findViewById(R.id.btnBlue); 13 14 btnRed.setOnClickListener(new View.OnClickListener() { 15 @Override 16 public void onClick(View view) { 17 btnGreen.setText("Green"); 18 btnBlue.setText("Blue"); 19 layout.setBackgroundColor(Color.RED); 20 ((Button)view).setText("Is Red"); 21 } 22 }); 23 btnGreen.setOnClickListener(new View.OnClickListener() { 24 @Override 25 public void onClick(View view) { 26 btnRed.setText("Red"); 27 btnBlue.setText("Blue"); 28 layout.setBackgroundColor(Color.GREEN); 29 ((Button)view).setText("Is Green"); 30 } 31 }); 32 btnBlue.setOnClickListener(new View.OnClickListener() { 33 @Override 34 public void onClick(View view) { 35 btnRed.setText("Red"); 36 btnGreen.setText("Green"); 37 layout.setBackgroundColor(Color.BLUE); 38 ((Button)view).setText("Is Blue"); 39 } 40 }); 41 42 } 43 }
2、CheckBox状态获取
要获取CheckBox状态，只需要设置OnCheckedChangeListener()即可。
1 CheckBox chkBox = (CheckBox) findViewById(R.id.chkFootball); 2 chkFootball.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { 3 @Override 4 public void onCheckedChanged(CompoundButton compoundButton, boolean b) { 5 if (b) strFootball = "Football"; 6 else strFootball = ""; 7 tvResult.setText(strFootball + " " + strBasketball); 8 } 9 });
完整代码为：
1 public class MainActivity extends AppCompatActivity { 2 3 private String strFootball = ""; 4 private String strBasketball = ""; 5 private TextView tvResult ; 6 private CheckBox chkFootball; 7 private CheckBox chkBasketball; 8 9 @Override 10 protected void onCreate(Bundle savedInstanceState) { 11 super.onCreate(savedInstanceState); 12 // this.setTitle("Button"); 13 setContentView(R.layout.activity_main); 14 tvResult = (TextView) findViewById(R.id.tvResult); 15 chkFootball = (CheckBox) findViewById(R.id.chkFootball); 16 chkBasketball = (CheckBox) findViewById((R.id.chkBasketball)); 17 18 chkFootball.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { 19 @Override 20 public void onCheckedChanged(CompoundButton compoundButton, boolean b) { 21 if (b) strFootball = "Football"; 22 else strFootball = ""; 23 tvResult.setText(strFootball + " " + strBasketball); 24 } 25 }); 26 27 chkBasketball.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { 28 @Override 29 public void onCheckedChanged(CompoundButton compoundButton, boolean b) { 30 if (b) strBasketball = "Basketball"; 31 else strBasketball = ""; 32 tvResult.setText(strFootball + " " + strBasketball); 33 } 34 }); 35 } 36 37 }
3、RadioButton与RadioGroup
要获取RadioGroup内RadioButton的选择状态，为RadioGroup添加选择事件即可。
1 rGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { 2 @Override 3 public void onCheckedChanged(RadioGroup radioGroup, int i) { 4 // TODO 5 } 6 });
首先在RadioGroup内创建两个RadioButton
1 <RadioGroup 2 android:layout_width="match_parent" 3 android:layout_height="match_parent" 4 android:layout_below="@+id/textView" 5 android:layout_alignParentLeft="true" 6 android:layout_alignParentStart="true" 7 android:id="@+id/rGroup"> 8 9 <RadioButton 10 android:layout_width="wrap_content" 11 android:layout_height="wrap_content" 12 android:text="男" 13 android:id="@+id/rbMale" 14 android:checked="false" /> 15 16 <RadioButton 17 android:layout_width="wrap_content" 18 android:layout_height="wrap_content" 19 android:text="女" 20 android:id="@+id/rbFemale" 21 android:checked="false" /> 22 23 </RadioGroup>
然后，为RadioGroup设置OnCheckedChangeListener()
1 rGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { 2 @Override 3 public void onCheckedChanged(RadioGroup radioGroup, int i) { 4 if(i==rbMale.getId()) { 5 result.setText("你的性别是：男"); 6 } 7 else if(i==rbFemale.getId()){ 8 result.setText("你的性别是：女"); 9 } 10 } 11 });
完整代码：
1 import android.support.v7.app.AppCompatActivity; 2 import android.os.Bundle; 3 import android.view.Menu; 4 import android.view.MenuItem; 5 import android.widget.CheckBox; 6 import android.widget.CompoundButton; 7 import android.widget.RadioButton; 8 import android.widget.RadioGroup; 9 import android.widget.TextView; 10 11 public class MainActivity extends AppCompatActivity { 12 13 private TextView result; 14 private RadioButton rbMale; 15 private RadioButton rbFemale; 16 private RadioGroup rGroup; 17 18 @Override 19 protected void onCreate(Bundle savedInstanceState) { 20 super.onCreate(savedInstanceState); 21 // this.setTitle("Button"); 22 setContentView(R.layout.activity_main); 23 24 result = (TextView)findViewById(R.id.textView); 25 rbMale = (RadioButton)findViewById(R.id.rbMale); 26 rbFemale = (RadioButton)findViewById(R.id.rbFemale); 27 rGroup = (RadioGroup)findViewById(R.id.rGroup); 28 29 rGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { 30 @Override 31 public void onCheckedChanged(RadioGroup radioGroup, int i) { 32 if(i==rbMale.getId()) { 33 result.setText("你的性别是：男"); 34 } 35 else if(i==rbFemale.getId()){ 36 result.setText("你的性别是：女"); 37 } 38 } 39 }); 40 41 } 42 43 }
