慕课网/安卓攻城狮视频学习及练习——简陋计算器

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简陋计算器

1 public class FActivity extends Activity implements OnClickListener{ 2Button btn_0; 3Button btn_1; 4Button btn_2; 5Button btn_3; 6Button btn_4; 7Button btn_5; 8Button btn_6; 9Button btn_7; 10Button btn_8; 11Button btn_9; 12Button btn_point; 13Button btn_clear; 14Button btn_delete; 15Button btn_add; 16Button btn_minus; 17Button btn_multiple; 18Button btn_divide; 19Button btn_equal; 20private EditText et; 21String string; 22Boolean flag=false; 23@Override 24 protected void onCreate(Bundle savedInstanceState) { 25// TODO Auto-generated method stub 26super.onCreate(savedInstanceState); 27setContentView(R.layout.factivity); 28 29btn_0=(Button) findViewById(R.id.button_0); 30btn_1=(Button) findViewById(R.id.button_1); 31btn_2=(Button) findViewById(R.id.button_2); 32btn_3=(Button) findViewById(R.id.button_3); 33btn_4=(Button) findViewById(R.id.button_4); 34btn_5=(Button) findViewById(R.id.button_5); 35btn_6=(Button) findViewById(R.id.button_6); 36btn_7=(Button) findViewById(R.id.button_7); 37btn_8=(Button) findViewById(R.id.button_8); 38btn_9=(Button) findViewById(R.id.button_9); 39btn_point=(Button) findViewById(R.id.button_point); 40btn_divide=(Button) findViewById(R.id.button_divide); 41btn_add=(Button) findViewById(R.id.button_add); 42btn_minus=(Button) findViewById(R.id.button_minus); 43btn_multiple=(Button) findViewById(R.id.button_multiple); 44btn_delete=(Button) findViewById(R.id.button_delete); 45btn_equal=(Button) findViewById(R.id.button_equal); 46btn_clear=(Button) findViewById(R.id.button_clear); 47et=(EditText) findViewById(R.id.editText1); 48 49btn_0.setOnClickListener(this); 50btn_1.setOnClickListener(this); 51btn_2.setOnClickListener(this); 52btn_3.setOnClickListener(this); 53btn_4.setOnClickListener(this); 54btn_5.setOnClickListener(this); 55btn_6.setOnClickListener(this); 56btn_7.setOnClickListener(this); 57btn_8.setOnClickListener(this); 58btn_9.setOnClickListener(this); 59btn_point.setOnClickListener(this); 60btn_delete.setOnClickListener(this); 61btn_add.setOnClickListener(this); 62btn_minus.setOnClickListener(this); 63btn_multiple.setOnClickListener(this); 64btn_divide.setOnClickListener(this); 65btn_equal.setOnClickListener(this); 66btn_clear.setOnClickListener(this); 67 68 69 } 70@Override 71public void onClick(View v) { 72string=et.getText().toString(); 73 74switch (v.getId()) { 75case R.id.button_0: 76case R.id.button_1: 77case R.id.button_2: 78case R.id.button_3: 79case R.id.button_4: 80case R.id.button_5: 81case R.id.button_6: 82case R.id.button_7: 83case R.id.button_8: 84case R.id.button_9: 85case R.id.button_point: 86{ 87if (flag){ 88flag=false; 89string=""; 90 91} 92et.setText(string+((Button)v).getText()); 93 94break; 95} 96case R.id.button_add: 97case R.id.button_minus: 98case R.id.button_multiple: 99case R.id.button_divide: 100{ 101et.setText(string+" "+((Button)v).getText()+" "); 102 103break; 104} 105case R.id.button_clear: 106{ 107et.setText(""); 108 109break; 110} 111case R.id.button_delete: 112{ 113if (!string.equals("")){ 114string=string.substring(0,string.length()-1); 115et.setText(string); 116 117} 118break; 119} 120case R.id.button_equal: 121{ 122getResult(); 123break; 124} 125} 126} 127private void getResult(){ 128string=et.getText().toString(); 129Double result=(double) 0; 130if (string=="") 131return; 132if (!string.contains(" ")) 133return; 134if (flag){ 135// flag=false; 136return; 137} 138flag=true; 139String s1=string.substring(0,string.indexOf(" ")); 140String op=string.substring(string.indexOf(" ")+1,string.indexOf(" ")+2); 141String s2=string.substring(string.indexOf(" ")+3); 142 143double num1=Double.parseDouble(s1); 144double num2=Double.parseDouble(s2); 145 146 147if (!s1.equals("")& & !s2.equals("")){ 148if (op.equals("+")){ 149result=num1+num2; 150} 151if (op.equals("-")){ 152result=num1-num2; 153 154} 155if (op.equals("*")){ 156result=num1*num2; 157 158} 159if (op.equals("÷ ")){ 160if (num2!=0) 161result=num1/num2; 162else 163result=0.0; 164 165} 166}else if (s1.equals("")& & !s2.equals("")){ 167result=num2; 168}else if (!s1.equals("")& & s2.equals("")){ 169result=num1; 170} 171 172et.setText(result+""); 173 } 174 175 }