我试图以编程方式更改imageView的颜色，但看起来只有setBackgroundColor（Color.WHITE）正在执行而setBackgroundColor（RED）却没有。
答案：我的RelativeLayout文件中的ImageView被另一个元素掩盖了。
当我调用happybirthdayimage.setBackgroundColor（Color.RED）时，没有任何反应。 Logcat表明应用程序已到达该行代码，但我没有收到任何类型的错误。
当我调用happybirthdayimage.setBackgroundColor（Color.WHITE）时，它的工作正常。
这是为什么？即使有工作，我也想知道为什么我的代码不起作用。
使用Android Studio v 1.0.2 在Nexus 5.0.1上进行测试
我已经包含了testForErrors类和GaussAlgorithm类，但我不认为这些是问题的一部分。
我的主要活动在这里：
package dayOfWeekApp;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnFocusChangeListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.view.KeyEvent;
import android.view.inputmethod.EditorInfo;
import com.example.com.piercestudio.R;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button calculateButton = (Button) findViewById(R.id.calculateButton);
final TextView resultView = (TextView) findViewById(R.id.resultTextView);
final EditText editTextField = (EditText) findViewById(R.id.editText);
final ImageView happybirthdayimage = (ImageView) findViewById(R.id.imageView);
editTextField.setOnFocusChangeListener(new OnFocusChangeListener() {
public void onFocusChange(View v, boolean hasFocus) {
if (!hasFocus) {
Log.i(testForErrors.E, "Lost focus, getting it back");
v.requestFocus();
}
}
});
editTextField.setOnEditorActionListener(new TextView.OnEditorActionListener() {
@Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
if (actionId == EditorInfo.IME_ACTION_DONE) {
calculateButton.callOnClick();
return true;
}
return false;
}
});
calculateButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Log.i(testForErrors.E, "CLICK");
String mArray[] = {editTextField.getText().toString(), "error"};
//error testing:
mArray = testForErrors.check(mArray);
if (mArray[1].equals("error")) {
Log.i(testForErrors.E, "error passed to main");
if(mArray[0].length() == 0){
//Intentionally blank so that touching the button does not give errors on pushing the button accidently.
}
else{
//-------
这是imageView应该变成红色的地方
happybirthdayimage.setBackgroundColor(Color.RED);
Log.i(testForErrors.E, "background RED");
//-------
calculateButton.setText(mArray[0] + " is not a real date");
editTextField.requestFocus();
}
} else {
Log.i(testForErrors.E, "no error passed to main");
if (mArray[0].startsWith("10/25")) {
Log.i(testForErrors.E, "Birthday entered");
happybirthdayimage.setBackground(getResources().getDrawable(R.drawable.happybirthday));
editTextField.requestFocus();
if(editTextField.hasFocus()) {
Log.i(testForErrors.E, "editText has focus");
}
else{
Log.i(testForErrors.E, "editText does not have focus");
}
Log.i(testForErrors.E, "background birthday");
editTextField.setText(null);
editTextField.requestFocus();
Log.i(testForErrors.E, "text to null");
} else {
这是转向白色的地方
happybirthdayimage.setBackgroundColor(Color.WHITE);
Log.i(testForErrors.E, "background WHITE");
}
}
if (!(mArray[1].equals("error"))) {
Log.i(testForErrors.E, "pass to gauss");
resultView.setText(GuassAlgorithm.getDate(mArray[0]));
calculateButton.setText("I think it's " + GuassAlgorithm.getDate(mArray[0]));
}
editTextField.setText(null);
}
});
}
}
XML布局：
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:background="#ffffffff"
tools:context="dayOfWeekApp.MainActivity"
>
<TextView
android:id="@+id/introText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Welcome! What day was it then? Enter the date in mm/dd/yyyy format and you'll see the answer below!"
android:textSize="20sp"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true" />
<TextView
android:id="@+id/typeDateHere"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="Type the date in here:"
android:paddingBottom="40sp"
android:paddingTop="10dp"
android:layout_below="@id/introText"
android:layout_alignParentStart="true" />
<EditText
android:focusable="true"
android:id="@+id/editText"
android:layout_width="wrap_content"
android:layout_height="50sp"
android:ems="10"
android:inputType="date"
android:layout_below="@+id/typeDateHere"
android:layout_toEndOf="@+id/imageView">
<requestFocus />
</EditText>
<Button
android:id="@+id/calculateButton"
android:layout_width="200dp"
android:layout_height="wrap_content"
android:text="Click here for the day!"
android:layout_below="@+id/editText"
android:layout_alignParentStart="true" />
<TextView
android:id="@+id/resultTextView"
android:layout_width="300dp"
android:layout_height="wrap_content"
android:text="The day will show up here :)"
android:textAppearance="?android:attr/textAppearanceLarge"
android:layout_below="@id/calculateButton"
/>
<ImageView
android:focusable="false"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView"
android:layout_above="@id/editText"
android:layout_alignParentTop="true"
android:layout_below="@+id/resultTextView"
/>
检查类和方法时出错：
package dayOfWeekApp;
import android.util.Log;
public class testForErrors {
public static String E = "TAG";
public static String[] check(String[] sArray){
String s = sArray[0];
sArray[1] = "error";
if (s == null || s.length() != 10) {
Log.i(E, "length out of bounds or null");
return sArray;
}
Log.i(E, s.substring(0,2) + s.substring(2,3) + s.substring(3,5) + s.substring(5,6) + s.substring(6));
try {
if((Integer.parseInt(s.substring(0, 2)) > 0 && (Integer.parseInt(s.substring(0, 2)) < 13)) != true) {
Log.i(E, "month out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "month out of bounds error");
return sArray;
}
Log.i(E, "month in bounds");
int month = Integer.parseInt(s.substring(0, 2));
Log.i(E, "month = " + Integer.toString(month));
//this activates only after the month has passed it's test
//if it were inside the "try" block 1: the rest of the code couldn't see it.
//10/25/1980
try {
Log.i(E, s);
if(s.substring(2,3).equals("/") != true) {
Log.i(E, s.substring(2,3));
Log.i(E, "first slash out of bounds");
return sArray;
}
}
catch (NumberFormatException e){
Log.i(E, "first slash error");
return sArray;
}
Log.i(E, "first slash in bounds");
//day
try {
if((Integer.parseInt(s.substring(3, 5)) > 0 && Integer.parseInt(s.substring(3, 5)) < 32) != true){
Log.i(E, "day out of bounds");
return sArray;
}
}
catch (NumberFormatException e){
Log.i(E, "day error");
return sArray;
}
Log.i(E, "day in bounds");
try{
if ((month > 1 && month < 13) != true){
Log.i(E, "month out of bounds");
return sArray;
}
}
catch(NumberFormatException e){
Log.i(E, "month error");
return sArray;
}
Log.i(E, "month in bounds");
switch (month) {
case 1:
try {
if ((Integer.parseInt(s.substring(0, 2)) > 0) && (Integer.parseInt(s.substring(0, 2)) < 32) != true) {
Log.i(E, "Jan out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "Jan error");
return sArray;
}
Log.i(E, "Jan in bounds");
break;
case 2:
try {
if ((Integer.parseInt(s.substring(0, 2)) > 0) && (Integer.parseInt(s.substring(0, 2)) < 29) != true) {
Log.i(E, "Feb out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "Feb error");
return sArray;
}
Log.i(E, "Fed in bounds");
case 3:
try {
if ((Integer.parseInt(s.substring(0, 2)) > 0) && (Integer.parseInt(s.substring(0, 2)) < 32) != true) {
Log.i(E, "Mar out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "Mar error");
return sArray;
}
Log.i(E, "Mar in bounds");
break;
case 4:
try {
if ((Integer.parseInt(s.substring(0, 2)) > 0) && (Integer.parseInt(s.substring(0, 2)) < 31) != true) {
Log.i(E, "Apr out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "Apr error");
return sArray;
}
Log.i(E, "Apr in bounds");
break;
case 5:
try {
if ((Integer.parseInt(s.substring(0, 2)) > 0) && (Integer.parseInt(s.substring(0, 2)) < 32) != true) {
Log.i(E, "May out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "May error");
return sArray;
}
Log.i(E, "May in bounds");
break;
case 6:
try {
if ((Integer.parseInt(s.substring(0, 2)) > 0) && (Integer.parseInt(s.substring(0, 2)) < 31) != true) {
Log.i(E, "Jun out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "Jun error");
return sArray;
}
Log.i(E, "Jun in bounds");
break;
case 7:
try {
if ((Integer.parseInt(s.substring(0, 2)) > 0) && (Integer.parseInt(s.substring(0, 2)) < 32) != true) {
Log.i(E, "Jul out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "Jul error");
return sArray;
}
Log.i(E, "Jul in bounds");
break;
case 8:
try {
if ((Integer.parseInt(s.substring(0, 2)) > 0) && (Integer.parseInt(s.substring(0, 2)) < 32) != true) {
Log.i(E, "Aug out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "Aug error");
return sArray;
}
Log.i(E, "Aug in bounds");
break;
case 9:
try {
if ((Integer.parseInt(s.substring(0, 2)) > 0) && (Integer.parseInt(s.substring(0, 2)) < 31) != true) {
Log.i(E, "Sep out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "Sep error");
return sArray;
}
Log.i(E, "Sep in bounds");
break;
case 10:
try {
if ((Integer.parseInt(s.substring(0, 2)) > 0) && (Integer.parseInt(s.substring(0, 2)) < 32) != true) {
Log.i(E, "Oct out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "Oct error");
return sArray;
}
Log.i(E, "Oct in bounds");
break;
case 11:
try {
if ((Integer.parseInt(s.substring(0, 2)) > 0) && (Integer.parseInt(s.substring(0, 2)) < 31) != true) {
Log.i(E, "Nov out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "Nov error");
return sArray;
}
Log.i(E, "Nov in bounds");
break;
case 12:
try {
if ((Integer.parseInt(s.substring(0, 2)) > 0) && (Integer.parseInt(s.substring(0, 2)) < 32) != true) {
Log.i(E, "Dec out of bounds");
return sArray;
}
} catch (NumberFormatException e) {
Log.i(E, "Dec error");
return sArray;
}
Log.i(E, "Dec in bounds");
break;
}
try {
if(s.substring(5,6).equals("/") != true) {
Log.i(E, "second slash out of bounds");
return sArray;
}
}
catch (NumberFormatException e){
Log.i(E, "second slash error");
return sArray;
}
Log.i(E, "second slash in bounds");
try {
if((Integer.parseInt(s.substring(6)) < 1700 && Integer.parseInt(s.substring(6)) < 2600) == true) {
Log.i(E, "century out of bounds");
return sArray;
}
}
catch (NumberFormatException e){
Log.i(E, "century error");
return sArray;
}
sArray[1] = "PASS";
return sArray;
}
}
package dayOfWeekApp;
public class GuassAlgorithm {
public static String getDate(String s){ //method declaration
if(s == "error"){
return "error";
}
String dayOfWeek = "some day"; //String declared with variable to test if anything is changing
int centuryInt = Integer.parseInt(s.substring(6, 8));
int decadeAndYearInt = Integer.parseInt(s.substring(8, 10));
int monthInt = Integer.parseInt(s.substring(0, 2));
int dayInt = Integer.parseInt(s.substring(3, 5));
Object monthName[][] = {{3, "March"}, {4, "April"}, {5, "May"}, {6, "June"}, {7, "July"}, {8, "August"}, {9, "September"}, {10, "October"}, {11, "November"}, {12, "December"}, {13, "January"}, {14, "February"}};
switch (monthInt){
case 1: monthInt = 12; //jan
break;
case 2: monthInt = 13; //feb
break;
case 3: monthInt = 0; //mar
break;
case 4: monthInt = 1; //apr
break;
case 5: monthInt = 2; //may
break;
case 6: monthInt = 3; //jun
break;
case 7: monthInt = 4; //jul
break;
case 8: monthInt = 5; //aug
break;
case 9: monthInt = 6; //sep
break;
case 10: monthInt = 7; //oct
break;
case 11: monthInt = 8; //nov
break;
case 12: monthInt = 9; //dec
break;
}
这是Charles Gauss开发的用于计算星期几的算法。 为什么我对这几个月进行编号，然后立即将其作为m + 1运行，然后再也不再使用它超出了我。这是算法。
int h = (dayInt + (26*(monthInt+1)/10) + decadeAndYearInt + (decadeAndYearInt/4) + (centuryInt/4) + (5*centuryInt)) % 7;
String weekDays[] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
dayOfWeek = weekDays[h];
return dayOfWeek;
}
}
**如果你能看到为什么我的editText在happyBirthday图像出现后失去焦点，那么你可以看到奖励积分。
答案 0 :(得分：0)
public class MainActivity extends Activity {
ImageView happybirthdayimage;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button calculateButton = (Button) findViewById(R.id.calculateButton);
final TextView resultView = (TextView) findViewById(R.id.resultTextView);
final EditText editTextField = (EditText) findViewById(R.id.editText);
happybirthdayimage = (ImageView) findViewById(R.id.imageView);
也可能是由XML文件中imageView的demensions引起的。我尝试了它，直到我在图像视图中添加了填充，它才会显示出来。